Invasive Species and Future Ecologies: Bugs, Viruses, Mussels, and Weeds

welcome to all of you this late morning afternoon this is the first Pardee seminar of the year and this is also my first party seminar as director at interim of this amazing place with an amazing set of people that you represent at least the first iteration of I hope to see many of you back again for for events just wanted to say that I deal in the John our good colleague and friend is with us in spirit who knows where on the globe he is that’s always hard to tell but this is very much in keeping with the kinds of issues that have been introduced and developed here at pardee and I want to put our meeting today in the context of a series of things that party has begun to mark out as its territory for thinking about not forecasting as you all know but in fact anticipating and thinking about what comes from our knowledge of the past our knowledge of the present and to introduce elements such as the ideas about complexity and unintended consequences of interactions whether they be economic financial political or ecological and one of the points I want to make today to this audience and with with my colleagues here is that this is a new additional direction that we’re adding to the part to the party to pantheon of ideas and people which is future ecologies it’s hard to imagine a future that doesn’t include the transformation of interactions between the natural world the context of human activity and the regime’s of health and of the different kinds of things that human beings engage in so this is today future ecologies is the subtext here the specific issue that I’ve asked our colleagues to talk about is invasive species and within this this the title there is the the implied notion perhaps that invasive species are these individual things that we know about in our daily lives or perhaps we know about in a global sense but in fact each of these invasive species and valves in ecology some succeed don’t some don’t the ecologies have to do with human action economics politics globalization of transportation globalization of economic interactions so let me do a brief introduction of my colleagues here since they’re all affiliated with Boston University many of you may know them but the the reason for their joining us today has to do with interactions unintended consequences and the particular perspectives that they bring to to understanding the longer term future as it says on the sign outside of our door let’s coffman many of you know les has probably spent more time underwater and more parts of the globe than anyone I know oh I didn’t know that what new information but less working in marine and freshwater aquatic systems particularly in my first getting to know him about his work in like Victoria so les is going to to talk a bit about his aquatic context for invasive species rich Pollock is my longtime colleague in the malaria malade maze project sponsored by the Ford Foundation we’re on our fifth year and final year what did I say cord thank you rockefeller how could I say that about her foundation rich also had the distinct pleasure and I can testify to this of working with one of the world’s great malaria logis Andrew Spielman we’ve dedicated our project to Andy left left us three years ago but rich reflects the work done in the harvard school of public health malaria laboratory which is is and was quite a visionary perspective that we’ve now incorporated into our project which will talk about this portion of the bugs he does work consulting work that has Massachusetts Tripoli one of my great experiences was just to be outside of a small hotel where we just had dinner in rural Ethiopia and to have him on his satellite phone calling down the helicopters to distribute the insecticides to Massachusetts counties that he would say yes this one no that not that one so it’s something but the globalization of health disease and response where’d you Premack that we’ve we’ve had less interaction except I’ve

known his name for a very long time he’s got an astonishing website those of you who don’t know any of you of course will know him and so Richard maybe I’ll is make the website well thanks oh whatever what about me this is recruiting can take place now so we have represented here three areas of invasive species but many of you represent a body of knowledge about very local contexts global contexts connections and then what are the set of interactions there looming on the horizon so the format we’re going to use today will be one in which each of our guests in order that we put them here and I’m not sure there’s a rhyme or reason to that but for less to talk about aquatic contexts rich to talk about various kinds of insects bugs in Richard talk abut vegetation and the geography represented here is in all of the cases goes from the very local Concord Massachusetts to wherever there happen to be bugs bed bugs is which brings bedbugs back from our trips to Ethiopia less of course no not only Lou England fisheries but fisheries in a very global context so we have a range of geographies I’m going to talk about not formal presentations but to engage one another and then to engage the audience in terms of these these issues so less on the two-term so the classic script if you want to be an invasive species is that you migrate to or get stuck into an environment where you no natural enemies you there had to have been two of them of course and then you go wild reproductively and you edged out native species push them off their turf take over the system and there’s a massive loss in biodiversity and that’s pretty much the story Lake Victoria the largest lake in the tropics was infected with a two metre long 100 kilogram exotic fish in 1954 called the Nile perch and what we’ve learned about the Nile perch and Lake Victoria since then gives the lie to the basic script for invasive species first of all most attempted introductions even deliberate ones fail when you move species from one place to another the likelihood that it will be able to survive long enough to adapt to local conditions is vanishingly small so what we’re hearing about in the terms of single species introductions are the exceptions and when Nile perch was put into Lake Victoria we actually know who did it because he raised his hand at the back of an auditorium the idea was a European concept that they would turn hundreds of endemic tiny little fish into large white fillets and this guy poured the fish into the lake and it actually took many successive introductions until the fish could reproduce in the lake at all and it took 25 years of Nile perch being extremely rare in the system until suddenly almost overnight beginning in 1980 the population went exponential and the biomass of the fish in the lake went from one percent Nile perch to eighty percent Nile perch within a five-year period so something happened they rediscovered sex a locally adapted mutant appeared the speculation that it hybridized with another species that was accidentally co introduced but it suddenly took off so the first lesson is it’s hard to do and it takes time for the introduced species to get local adaptations and what happens after that is highly unpredictable in the case of the Nile perch it began to destroy both the habitat and to consume directly about 400 species of fish that live nowhere else in the world and did you ever see the movie Brazil okay so you know the whole world is run by plumbing and and and you know HVAC systems and things so imagine that that HVAC system is the ecosystem and you just take a machete to it that’s what now perched it and there were things just oozing out of corners all over the place there were there were explosions of abundance of Lake flies that would emerge from the lake and cloud so thick and this was out of season would happen all year that if you pass through in a boat you would choke if you didn’t put a cover of your face small shrimp just exploded in abundance they began to form a quivering mass that

covered the bottom of the entire Lake the lake one anoxic and the shrimp was one of the few animals that could survive down there one native species of fish went exponential a tiny minnow and all the others essentially vanished except for the Nile perch and another species Nile tilapia that was introduced at the same time and we foretold the ultimate collapse of the system and the annihilation of the protein base for 30 million people and that is exactly what did not happen because what did happen is that this new system although extremely volatile and violent and changing rapidly year-to-year was unbelievably resilient and still is the Nile perch had so many sources of energy that they could switch to as the system went through its kaleidoscopic turn it kept changing in nature from year to year the purchase switched prey and the system remained mostly a Nile perch engine and two to four hundred million dollars a year foreign revenue from the fishery that was developed to follow the Nile perch brought much-needed economic security 23 countries in East Africa now of course most of that money went into private coffers there are a lot of lurid tales attached to that so in addition to the ecological surprises there a huge economic and social surprises how many of you have seen the film Darwin’s nightmare okay this is a very bizarre film by a friend of mine or he became a friend in the process of making the film he went to Tanzania to make a film about the introduction of Nile perch in the extinction of the native fishes and he called me halfway through the film from he would call at three in the morning from phone booths and apologizing that the movie was no longer about fish was about people because what he discovered what he claimed the discoverer were two things that we knew one that the introduction of Nile perch and the growth of an export fishery cut women out of the commodity chain completely normally they the men catch the fish and the women sell them and as a result in order to get fish to sell the women had to sleep with fishermen to just get the leftover frames after the giant Nile perch had been filleted aids took off children were orphaned they began to burn the cartons that the fish was shipped in the styrofoam to get a high there was just huge social unrest the number of jobs at Lakeside numbered in a few hundred thousand as a result of the Nile perch 10 million people flocked to the shores of Lake Victoria so all of a sudden you have this enormous detached population feral population of people who have nothing to do no jobs no nutrition and on top of everything else Hubert who made the film asked what happens to the planes that carry the Nile perch to to Europe how do you afford to bring them to Africa and his answer which the Tanzanian government disputes is that those planes were loaded with guns and tanks for the wars in central Africa and that material is transshipped room wanza to Angola and the DRC and the Central African Republic all of this from Nile perch from the introduction of an exotic species now some people will say that much of this would have happened anyway but I think the important thing is that when you modify a biological community the potentialities and the constraints change utterly and you don’t know what’s going to happen you also don’t know if it happened because of the introduction or because of other things it’s a meaningless question the whole constellation of interactions has been transformed so the take-home lesson from Lake Victoria about introductions is that when you introduce a new element or many new elements actually many species who introduced the lake victoria when you introduce them you change the game rules you don’t know exactly how things are going to reorganize but what happens is you create a new kind of community that has been called recently a no analogue community an example of a no analogue community is the Pleistocene megafauna today there’s nothing like what dissolved into the La Brea Tar Pits we don’t have you know giant condors and ground sloths and elephants roaming around North America that the whole system is different now similarly the oceans of the world have been stripped bare of the surviving megafauna the great white sharks in fact all the Sharks the dugongs and manatees the turtles they’re missing and so what we

have now in the world ocean is a no analogue community that’s the result of extraction of annihilation so it can go either way you can add or subtract but when you do this to a complex system the outcome is uncertain and always exciting yeah that’s a hard act to follow it’s a great start switching gears now for something completely diff I think it’d be helpful to sort of step back and to help with the discussion later on and for the audience members to better understand what it is we’re talking about here and then I’m going to tell my own stories that I probably can’t hold a candle to yours that on that oh okay all right well if I can do that what is an invasive species you ask ten people you want to get 11 different answers but it’s something that’s actually defined in law federal regulation an invasive species means an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health all right well that could be just about anything but it gives us a framework yeah part of my training is in epidemiology and so I sort of consider the world is sort of like a big host and all these little infections coursing through what is or what is what causes a disease in one kind of animal for instance the Lyme disease bacteria in white-footed mice causes essentially no pathology or very little but you put it into the wrong kind of animal like one of us and you end up with disease things are different and the infection still takes but the the way we perceive it is considerably different so where am I getting to with us that is that a members of a species which are part of the the normal native ecology in their own home range they’re not an invasive species if members of that group are transported intentionally or accidentally elsewhere and if they cause this kind of harm well okay they’re considered an invasive species but it kind of dams the whole species in some respect it depends on where they’re introduced to or where they’re invading the seasonality the climate so the same tick that is that that might arrive at Boston Logan in February and not have a chance in surviving if it arrives here in June and somehow gets out and lays eggs well it could be a big problem so it’s a judgment call as to whether you consider it an invasive species or not enough on the etymology of all of that okay the other thing is a larger conceptual idea is is this what do we do about it and I know that’s not necessarily the goal of this session but the vast sums and energies put into trying to interdict what potentially invasive species and it’s a lot of effort and money is still going towards that but rarely is there a good risk assessment as to whether it makes sense to do that versus trying to to stop the things once they’ve arrived and there’s a great debates raging right now among scientists in the invasive biology community on this so this might be a theme that we can talk about a little bit can we stop something from coming in can we predict what it’s going to do when it gets here and if it does get in is there anything we can do about it or is it too late okay so those are the general comments the specific things a couple of examples so I deal with all sorts of insects particularly those that find me and you folks attractive so mosquitoes and ticks and fleas and bedbugs and lice and all those lovely things that that creep people out it’s how I get my my fun so those things and things they transmit so a couple of examples from those those kinds of individuals in the 1930s actually late 1930s there was a an entomologist working for the Rockefeller Foundation I was wandering about in Brazil he was there consulting for the Brazilian government and for the Rockefeller Foundation on the epidemic of yellow fever that was raging through the area

trying to do something about it one of his days off he was wandering about and he looked down into a puddle and he noticed a mosquito that he instantly recognized was one that shouldn’t be there he called an awful ease gambiae it’s one of the most significant vectors are the vector complex in sub-saharan Africa and this is one of the members of that group he knew it shouldn’t be there he knew the potential even though there was malaria various types transmitted by local mosquitoes and it did burden people caused the illness and death he knew that this mosquito if it became established and it likely was established would cause havoc and he went to the to the government officials who said uh we already have malaria why we already have mosquitoes that transmit it why do we need to worry about this yes it’s an introduced species big deal it’s just it’s another mosquito well as this fellow had anticipated the population of this mosquito blossomed and the result was a tremendous epidemic of malaria I was much more efficient as a vector that many more people that became infected by the various kinds of malaria parasites much greater Morton morbidity and mortality and it wasn’t until many years into this when none of the workers were able to to harvest the crops that the government decided okay let’s do something about it it’s a very long story it’s a fascinating story there’s a whole book written about this the upshot is it’s one of the few examples where a an invasive species an introduced mosquito that was actually eradicated from a country actually eradicated from hemisphere if it if it had not been contained by geographic and topographical barriers it probably would have spread throughout South America and would still be causing tremendous death to this day a little closer to home and more recent in time you all know about West Nile virus well that’s an invasive virus it’s not native to this country what is now it’s here it’s likely going to stay but that’s a fascinating story by itself it’s probably the fourth Horseman of this complex relationship the mosquito that mainly transmits West Nile virus from bird bird is QX pipiens at least here in the east that’s an introduced species that probably came in in the earliest days of sailing vessels probably in the bilge water of those old sailing vessels and it established it does very well that’s particularly well around human habitation and disturbed environments and it’s with us it’s not too much of a pest by itself but it’s out there every catch basin on the streets are the storm sewers is a wonderful habitat for this mosquito every gutter on our homes is a great habitat okay what else so it’s that’s one of the the horsemen a second one would be the Japanese creeper this vine also known as boston ivy which covers the sides of our academic buildings and other buildings it’s a wonderful habitat for it’s an introduced plant but it’s also a wonderful habitat for the third Horseman which is the European or house sparrow which is brought in in eighteen sixty eight or so for various reasons it’s worth a whole lecture by itself now that bird is a very good host of a blood meal host for these mosquitoes it also is particularly suitable for harboring West West Nile virus for about a week or so which is enough time to amplify the virus and allowed to be transmitted by yet other mosquitoes and then well then the virus so the fourth one which arrived here in North America in 1999 and is spread right across the country and these things are now part of our local ecology and there’s still people deciding what we need to eradicate it there’s something we must do to to control it or eliminate it there are no good answers but that’s another example I’ll just finish up many other things that might be of interest that whether other mosquitoes we have two perhaps three new mosquitoes that have arrived in Massachusetts in the last few decades one is just right lapping at the edge of the Massachusetts border and it might be here what if we see the effects of global warming maybe this environment

will be more conducive to it and this mosquito can also be a pest and can transmit a variety of things there are hundreds and hundreds of species so we could go off on a tangent with any one of these but those are just a few examples and and actually I used a dozen or so as part of a full year course at Harvard that I entitled uninvited guests it was just on invasive species so I think I’ll stop there and you know okay look read introductions so far thanks very much and again kind of just repeating the definition of invasive species so an invasive species is really generally people call it a non-native species which increases in abundance to the detriment of that of the native species and we have lots of examples of these in Massachusetts and I’ll really talk mostly about plants justice to give that perspective and a general these kind of invasive species out-compete and replace the native species it’s really a huge problem in the United States which just keeps getting more attention all the time so a recent estimate was that forty-two percent of the endangered species in the United States are threatened by invasive species so forty-two percent of this of the endangered species are directly threatened by in by invasive species so it’s a very major problem for maintaining the biological diversity of the United States there’s also some economic estimates which people always kind of make up out of the air I think they’re kind of a lot of uncertainty about these estimates but one estimate is that invasive species class tonight say it’s a hundred and twenty billion dollars per year in costs but most of this cost is really the cost of getting rid of agricultural weeds so it’s really agricultural weeds which are non-native invasive species I mean really the main threat in terms of our economy so these invasive species have come here because of a lot of different reasons a lot of them as was mentioned came by the Europeans when they first arrived in North America Europeans not only brought ship ballast but they also just were were wildly releasing species they wanted North America or wherever they went to be as much like Europe as possible so they were just releasing all kinds of plans and birds and insects and some of these species became invasive a lot of species were released as part of agriculture horticulture aquaculture so for example in the case of plants large numbers were plants were grown in people’s gardens because they were beautiful or economically valuable and then they became invasive in the surrounding area and those dramatic example that we have around here probably is purple loosestrife which was planted as as an invasive species or as planted as an ornamental species and then started spreading into all the wetlands throughout New England a lot of species are transported by accident and again Richard mentioned some of those another example is biological control a lot of our most invasive species were introduced to control something else and then became invasive on their own a point has also been made that most species are don’t become invasive and there’s kind of a ten percent rule of invasive species which is that about only about one out of every ten species which is introduced into an area will be able to reproduce on its own and only about one out of those ten species will become invasive so they’re about 5,000 plant species which have been introduced into the United States which some seems unbelievable but five thousand species have been introduced into the United States and out of these you could figure about 500 reproduce on their own and about 50 of them are really truly invasive so it’s that the ten percent rule again just think about local examples so if you go canoeing on the Charles River you’re just struck by the fact that the charles river is full of water chestnuts so water chestnut plant is just just totally bogging the waterways of the of Charles River or water milfoil is another example and they were introduced up as ornamentals or the case of water chestnut maybe for the edible tubers and they just you know have become invasive and they have out competed the native species are taken over habitats with it where there were no native species the general rule of thumb for invasive species is that invasive species occupy habitats which are altered in some way and so they were able to out compete the species because the environment has been altered in some way which they can take advantage of and most obvious kind of place are very disturbed environments so environments where there’s a lot more kind of digging up of the ground clearing cultivating of the soil or digging up of the soil create conditions which are suited to invasive plant species because they’re able to tolerate the disturbance much more than the

native species but in fact the whole environment has now become disturbed by human activity so if you just think about things like acid rain so the soil is more acidic than it used to be or nitrogen deposition so when we burn fossil fuels is all this nitrate dust which is created which then comes down and the environment the soil environment has mount much more nitrogen than in the past and a lot of these evasive species probably are better taking up nitrogen from the soil and this allows them to grow more vigorously but we can also think about things like climate change so as temperatures get warmer a lot of the invasive species might be able to tolerate the warmer conditions more than the other species and then we also think about habitat fragmentation so we just have a lot more roads in doing Linden trails and people walking and people using mountain bikes and with all this kind of breaking up of large continuous habitats into smaller pieces it provides more of an opportunity for the seeds of plans to get in or for invasive insect so are invasive animals to sort of come into these habitats where they couldn’t so in the past people used to say the place where you see the most invasive species are the most disturbed habitats and that’s certainly true so if you go to the Charles River for example or allowing the muddy river it’s virtually all invasive species are non-native species and very few native species are still along the charles river there’s still a few there but not so many but generally as you go to less disturbed habitats there’s more native species and but even when you go into the most remote areas there are still at least some invasive species in those areas but very few I mean if you go to for example in New England into kind of country areas of New Hampshire there’s probably no invasive plant species inside of the forest this may be a few invasive insects or birds that can get in there but eventually those areas will become disturbed enough so they will be probably invade at least by some species one interesting example is conquered conquered conquered is great because conquered is the most well-documented place botanically probably in the United States and when Thoreau was working in Concord about eighty percent of the species were native about twenty percent of the species were non-native some of those species were non-native but not invasive probably most of the non-native species that were growing in Concord were not invasive but some of them were invasive even in Thoros time so about eighty percent of the species were native species and twenty percent were non-native in the last hundred and fifty years we’ve changed that so there’s now sixty percent native species and forty percent non-native species so the native species are not only declining in numbers so the native species are declining in numbers the native species the non-native species are increasing in numbers but also the individual species within concord that are still there are declining in abundance so many native species which used to be common in concord are now rare and many of the non-native species which used to be rare are now very common an example of this is garlic mustard so garlic mustard was this non-native species it’s this little small mustard plant with white flowers and they used to be present in low numbers 150 years ago in occurred and throughout Boston and then beginning around 20 years ago garlic mustard sort of transformed it went from kind of you know kind of a nice interesting European species that was often found near polluted habitats where there was a lot of extra nitrogen in the soil or places where people walk dogs you could often find garlic mustard plants and suddenly garlic mustard exploded 20 years ago and has now become extremely abundant and a very aggressive invasive species in the southern New England area and in Concord and that’s probably because it’s better able to take up nitrogen than a lot of the native species mostly talking about New England but I mean this is really happening throughout the world and one very dramatic example for those of you from the west coast know about is the plant called brohm grass so traditionally in the California landscape a lot of the grasslands in California and other places in the West they were often perennial grasses and shrubs in a lot of the the areas of the west and but there were no annual grasses which lived in in the prairie areas and or the Prairie or chaparral or desert areas and in these areas we now have European and Asian grasses which are called brohm grasses which are annual grasses and these grasses grow very quickly in the spring set their seeds and then afterwards they’re the dead plant material catches fire and we now have fire in the desert sand in the chaparral much more frequently than ever occurred in the past and as a result of these fires it tends to kill a lot of the perennial grasses and kill a lot of

the shrubs and makes the area more suited to annual grasses and the reason that the grasses were able to grow there is because they’re able to take up the nitrogen that’s now in the soil and this allows them to grow faster than any plan could have before and so these areas are being transformed from being ecosystems with mostly perennial plants to now mostly non-native invasive annual plants mostly grasses so it’s a whole transformation of ecosystems characteristics so what are we going to do about invasives there’s a number of strategies for it for dealing with in vases but probably the most important one is never let them get there in the first place so there are certain known invasive species and it’s very important that there be border controls or very close monitoring to make sure that the invasive species sort of doesn’t get there in the first place and the next thing is monitoring habitats where the invasive species aren’t there but monitoring to make sure they don’t get there and this is something that we need a lot more of and particularly to eradicate them when they first arrive so an example of this is the spotted knapweed cisplatin that we’ve is a terrible problem in the western United States and they’re starting to become isolated patches of it in southern New England and but nobody’s really watching it so it’s going to get established here and it’s going to become very aggressive in our habitats but nobody’s really doing anything about it it occurs in West Concord train station and I’ve told the town officials about it but they don’t seem to be very worried about it I thinking to wake up one day and it’s going to be everywhere in Concord so that’s kind of you know things need to be monitored and eradicated whence they once they first arrived but before their very common once invasive species become really common once invasive plant species become very common they’re incredibly difficult to eradicate because they often have a huge bank of seeds in the soil which comes up year after year are often you can eradicate 99% of them but one percent remains and it can quickly produce seeds which then repopulate the whole area so it’s very difficult to eradicate things and again kind of an example from Concord there was a proposal a few years ago to create a invasive to make Concord an invasive plant free zone the plan was to eradicate all the invasive plants from Concord and they did it kind of as a trial they they tried to eradicating all the the oriental bittersweet from this one patch of land that was about 50 feet by 50 feet in a kind of a hundred several hundred acre woods and apparently like whole crews of volunteers were out there cutting and poisoning for like days and they just managed to complete this one patch of 50 p by 50 feet and by the next year it looked completely unchanged I mean all the bidders we just simply grew back so you really it’s very difficult to eradicate things once they get established the only way to really eradicate them is by biological control so trying to find very specific insects that only eat that plant and no other that’s probably one of the only ways of getting rid of invasive plant species and there’s a very interesting case of great meadows again another example from Concord where purple loosestrife was a terrible invasive plant there and without competing all the native plant species on which the native insects and wildlife dependent so an invasive or a biological controlled beetle was released into great meadows it eradicated the purple loosestrife or largely eradicated from great meadows and another invasive species the American Lotus came in and took over all the same habitat so we had this kind of replacement of one non-native species by another non-native species and then kind of a final comment so one of the big discussions about invasive species which is presently taking place is whether we shouldn’t just accept them in a lot of circumstances so there are a lot of very disturbed habitats particularly in cities or roadsides or places where you have a lot of changing environmental conditions where these invasive species are creating new kinds of habitats new ecosystems but they’re providing ecosystem services so there they are absorbing carbon dioxide they’re producing biomass which can be harvested they’re stabilizing the soil and so they may be providing some benefit to us and in situations where we can never reach the native vegetation anyway because of the seed bank because of the altar conditions we should just learn to love the invasive species and accept them for who they are thank you and what I’d like to do now is to open the discussion for questions and comments and logs to the Aces brought here these are anecdotal in one sense but there’s also I think overall one has it has a sense here of that notion of future ecologies the interactions

particularly that the Richard on the other side entry introduced one last dimension I’ll add here for us to consider then please raise your questions would be the other kinds of invasive species in which one sees on a landscape we began our project and working in southwestern Ethiopia five years ago look at the landscape look at the varieties of species that were there insects plants different kinds of ecological context so where water was and what we found was at the end of five years it had become totally covered engaged with one plant maize corn there’s rich why because not because ecologically was more suited one had to provide fertilizer add nitrogen had to do a whole series of things to cultivate it it was human interest in the economic value and the government policy to say grow this not that resulting in a transformed ecology and in effect the human transformation was a little bit like what you like Michael Pollan pointing out that the reason people like marijuana and tulips and the examples he has is because humans like it persuades humans this is the thing to begin to transform their own environment so sometimes it’s invasive species that are unwanted unexpected sometimes very much expected and provided for by humans so that’s a dimension there a little bit like perhaps Nile perch but with that change in this one environment we’re talking about the one ecology included new news species of mosquitoes mosquitoes no one anticipated new varieties of everything including humans transformed by the economic and government context they’re in so with these examples and our distinguished colleagues who know a great deal well first of all comments from the group and then let’s move to the audience which one thing about the picture the three non-natives in that this is the center picture where I’m one of the non-natives there in Ethiopia holding up maize which is non-native for that continent and if you look closely maybe those in the very front row can see tiny little holes in the leaves those are caused by the European corn borer so it’s yet another well it’s increasing diversity in some odd way locally all of these non-natives in there enough silliness let me we start the ball rolling by asking my colleague I left a question the issue of eradication how practical is it and I think we need to define what what eradication is can you have partial eradication or is that population suppression eradication in in my lexicon is complete elimination and that’s very very difficult to do it’s almost never done it’s never successful the closer you get to reducing the population of whatever the pest is the more asymptotic it becomes it’s more difficult to find the remaining remaining individuals the more expensive it is and at some point you have to accept failure so that that’s an issue you folks try to eradicate these conquered as well then this for a club and bottled water whether through it it’s probably very very difficult to eradicate most species once they’re established but control is another possibility so for trees for example invasive tree species like the Norway maple it’s probably possible to control that because they grow relatively slowly they don’t reproduce until there are many years old so that that could be a target but for garlic mustard for example eradication is probably impossible because the seeds live for 10 years in the soil and so that’s probably impossible for biological control you’re also not really going for eradication that with the biological control does is it really kind of the insects attack species when they’re in concentrations and so you often have you know scattered individuals much further away which which can survive is brought in our perspective a bit if you back up a minute so what we’ve got going on in the world now are my new enclaves that actually vaguely resemble what was there before humanity took over the world and then you have humanized environments which constitute what forty percent now or so of the land surface with some very very large percentage of the land surface and then you have what Richard number one or two over there alluded to tell me the plan guy the plant guy alluded to which is that in the marginal

zone between the humanized landscape and the wilderness what’s left of it is this vast area that’s been compromised and in that kind of zone around people the anything that gets an edge anything that people have moved their potential invasives exotic species are likely to do better uh and establish a new kind of community then are you to see the wilderness come back into that area and this is a reversal if you read a literature from the 19th century people were astounded at the vigor with which jungle or any natural vegetation type would recolonize space that was left fallow I think we’ve seen it go the other way now and it may be because of this monumental Bank of seeds and eggs and propagules of exotic things that are just waiting there to monopolize these marginal areas so it’s I don’t think I think the genies out of the bottle here I don’t think there’s still even possible to go around eradicated things I think it’s a totally different situation and if you look at the you know the army that’s on the frontiers trying to save what’s left of wilderness it’s kind of a pathetic pathetic scene so I think the real question is what can we do with this middle ground can we tip it a little bit the other way I just have one sort of come in for the bug guy and actually tells us also which is that I’m kind of struck by all three of us have mentioned examples which have happened very recently of invasive species so we’re not talking about like some textbook examples that took place in the distant past but that all of us within the last 10 years have seen tremendous transformations of invasive species actually at this point maybe we could invite Tom coins to make a comment because he’s studying white nose syndrome and bats which is also a very recent invasive species you want to mention that one well actually I always just comment on a broader context each of you basically gave examples the underlying theme was competition as a driving force for invasive species but it turns out there there’s more than competition and and many animals for example that and I bring up the idea of what we call pathogen pollution which is occurring with emerging diseases and certainly a fungus that causes white nose syndrome is is one of them but many our environment which is both plant and animal and fungi and microbes and so on we need to really consider that microbial evolution of microbes is rampant and and that many animals for example don’t have the immune system there that to handle introduced pathogens and this fungus that is killing bats as one example that the immune system is compromised or not effective against the this invasive pathogen but there are many others of viruses and I think rich could probably address this better than any of us here having not only a bug guy but he’s also a virus guy and a bacteria guy and so on so I’m an amazing hope baby enrich it could could continue this discussion a bit about one of the problems that in terms of invasive pathogens is really affecting our environment and will continue to infect our environment we can’t really control many of these viruses and bacteria and fungi so rich I there’s not much more to add to that I it’s a great jumping-off point well we are bringing in a bunch of things whether they be microbes viruses whatever that we’ve never seen before and there are no natural predators from the larger creatures the insects they’re not necessary natural creatures that they’re there maybe not native creatures that will feed on the plants that are brought in it’s going to be expanded to any kind of ecological system so there’s there’s no immunity in that respect then there’s us there as a tangent to that they’re viruses that we have as an example mutate well all of these creatures mutate and so we end up with these odd populations offshoots that act differently which the host is no longer as able to defend itself against so we see examples of that as well so this is a dynamic and complex system it’s constantly changing we don’t know where

we are necessarily at this moment we don’t know where we’re going to be next week let’s move to we have about half an hour and what I would like to do is to engage the audience to to ask questions to offer comments and perhaps my last one would be from the chair is to say that what we should anticipate is the unanticipated that in fact if we expect complexity and expect interactions and we look to identify them in to future generations both but measured by decades and by the reproductive calendars of these these various species that that’s one of the ways of looking forward and say we have to expect these unexpected responses and learn from them both passively as scholars but actively is people like actually everyone here who’s taking action and making choices about what to do and what not to do I think you’ve heard that today so questions we have wait for the microphone one back here and one back here hi thank you Jono mendler as far as I would like to ask you to go back to kind of Jim’s opening framing looking at the issues of complexity and specifically I’m wondering about if you can elucidate a little bit more on the role of complexity in relation to the resilience of systems obviously we really have no more pristine systems on the planet whether you want to say that you know the anthropogenic influence of climate change or industry you know many of you mention the you know the opportunistic species that are capitalizing on more nitrogen but you know we also have these temperature changes that are kind of you know pushing whole ecosystems horticultural zones are moving we see in you know global fisheries the transformation of biomass you know from fish to jellyfish and I think you know we need to we need to look at what creates the opportunities and how to manage if we can’t eradicate and I’d like to maybe to give you a little bit of focus ask how you feel about management approaches like marine protected areas or the you know terrestrial preserves as ways to conserve complexity rather than specific biodiversity well what would you want go around well I think in complexity is our only hope because one of the things about complex systems is they they don’t have an infinite number of states they can assume and something like a preserve whether it’s marine or terrestrial what it really creates is a nucleus with in which toward the center there’s the highest probability of that original system persisting and it all depends upon how well enforced it is so we looked at marine reserves you just finished a study in which we looked at marine reserves in 23 countries what we found is that like 99.9 bar not enforced but the ones that are work even if they’re astonishingly small so we make a lot of the extraordinary aggressiveness of these invasive species but in fact a natural i mean a non humanized system given a little bit of a chance can become a nucleus for the recrystallization of a phone and biota that’s much more similar to what adapted in the NC to in that environment so I don’t see marine reserves as a solution to everything I see parks and reserves as kind of the seeds that could so a new no non analog community that some strange combination of what was there before and the forces that we really can’t resist anymore I’d like to mention the fact that in so many of our conservation lands which have been studied in Massachusetts what we’re finding is that the number of species in those parks like in Concord or the Middlesex fells or in needham massachusetts that the number of plant species in those areas is declining over time that native species are being lost and they’re not being replaced by either native species or non-native species and so one thing which many biologists are considered right now is the idea of what it’s called assistant migration so instead of just simply watching our conservation

lands for example I conquered declining in terms of abundance over time that we actually look to the south for example to a place which is a little bit warmer like Connecticut or Rhode Island or New Jersey and we start transforming or transporting species from those places further to the south of here into concord so that they will be able to establish themselves and be able to adapt to the warming climate this is called assisted migration and this is really one of the most exciting and kind of most discussed topics right now in the field of conservation biology the argument against doing it is that even though you might be increasing the biodiversity you might accidentally be creating new invasive species so you might be taking species from say Connecticut and bringing them here they would become invasive and so this is why most people think that we shouldn’t be doing this but I’m actually one of the people who believes that we should do it because the chance of a rare species from kinetic at a rare native species from Connecticut bringing it up you know one or two hundred miles further north of its existing range and then it becoming invasive is so astonishingly small and that what’s almost certainly going to happen is that these wild flower species probably won’t grow very well it’s very difficult to create new populations of rare wildflowers and so I think we should start doing it now and gaining that experience and as the context of climate change introduced there is a conscious part of the process of dealing with thee and also political ecology since this has to do with law enforcement of law maintenance of a public awareness of issues so exactly with the mix yeah I have a question for dr. Premack so you mentioned the example of the garlic method and how it really just likes all the extra nitrogen in the ground is there any examples of similar species or a species that really focuses on one aspect completely depleting it and then the ecosystem returning back to normal or to its baseline yeah I think generally what people say is that invasive species alter eco systems and take them away from their their original condition so I think that there’s really no example I can think of where something comes in and alters it back to the original condition where it can’t survive itself and I haven’t heard about that I mean think that they generally really just totally transform an ecosystem and you experience that yourself if you ever going canoeing on the Charles River because you know the past used to be able to sort of you know go down the Charles River and the whole river was pretty much sort of open bank to bank and now you just have all this water chestnut forming this sort of carpet there which is very difficult to move through it by being difficult to move through it it means that the water chestnut can grow even better because there’s nothing disturbing it so I think that in general invasives tend to alter eco systems in a way to their own advantage so you’re saying there’s no clemency in succession yeah there’s no succession back to the original situation these in these invasions the invasives are only healing in the sense that they will take a disturbed habitat and often stabilize it so in that sense they provide benefit so in most areas in New England if you have very disturbed soil after say construction or creating a house or building roads and you don’t do anything to it that gradually plants will come in there and they will stabilize the ground they will form a eventually a forest canopy there and that will tend to prevent erosion so that in that sense it’s a very beneficial function and that’s why a lot of at least some to college just think that we should be embracing these non-native species we did ever over compete with itself too much me to the point where it excludes itself yeah I guess I mean allylic chemicals can it ever boys in itself well I think that some trees do this every so I mean even some of these non-native trees for example so if you for example establish a black locust for example so black locust will form these stands and then in the inside of the stand there’ll be no black locust seedlings because it’s two shaded for them but that’s kind of the natural process of succession that many trees won’t grow up under there under a dense canopy cover that they either from others that they create themselves but kind of on the fringes of the black locust for example if you look at a black locust and you know in the fringes of it there’s just huge amounts of black locust your black locust seedlings and demography identify yourself my name is Marian Wong from biology department and I forgot a question I guess mainly for dr. Kaufmann in that even in that you mentioned when the Nile perch was introduced there was a trade-off between a reduction and diversity of the native cichlids by an increase in resilience of the remaining ecosystem and I can see

that in some respects and increase resilience of an ecosystem may be actually beneficial for example to the human communities that rely on fish as a source of protein and so require this kind of food security so in these kinds of situations I was wondering what your opinion is about how much we should control that particular ecosystem as opposed to simply embrace it and trying and find well the wonderful thing matters is we don’t have a lot of choices in that case we’re not going to get rid of nile perch we’re trying very hard to do it they’ve succeeded in there are two kinds of overfishing growth overfishing which means to take all the big ones but they’re still big enough to mature so you don’t run out of them and recruitment overfishing which means you take so many big ones down to such a small size they can’t reproduce anymore and then you lose them so in in Lake Victoria we only have growth overfishing and that’s that’s why they’re resilient the other reason and resilient is that when you take the Predators down the native pray go up and the Predators grow faster on the native prey than on the exotic ones so there’s this that’s the most beautiful thing we learned so there’s there’s a complexity of de novo complexity in that system that wasn’t there before but I want to be careful it’s not that the new system is more resilient than the old it’s that we expected anything but the old to be untenable and we were wrong it is possible to have an extremely low diversity system that is resilient and I find that frightening because it means that all the value that is stored in the biodiversity of the world is at risk much greater risk than we appreciate it hi my name is anne-marie I’m from the College of Communication a science journalism student I have two questions the first is do invasive species ever become native species over a certain period of time and the second question is for dr Premack you mentioned biological control do in do you know of examples where invasive species are used as biological control for other invasive species or do you always or are methods or specifically cater to using native species as methods of biological control so I mean the first question I mean do invasive species ever become native I mean they don’t because they’re not here originally they didn’t evolve in this area so they would always be classified as non-native but one thing which is interesting is that sometimes native species are sometimes considered as invasive so sometimes people alter the conditions such that native species will increase tremendously in abundance and so for example we’ve altered the conditions right now in New England such the deer are essentially invasive so the deer populations have become so large that they become nuisance that they’re actually their numbers have increased to the point where they have very serious negative consequences for wild flowers in our for us and they’re causing erosion they’re probably vectors of the carrying Lyme disease from place to place so many people would say that they are like invasive species in this area or another example might be the Coyotes probably not here originally but certainly increasing an abundance now and the the second question is where do we find biological control agents we always find biological control agents in the places where the invasive species originally came from so if people biologists want to find biological control agents they go back to the original habitat where that species occurred and they find a an organism which is a specific predator on the invasive species and so in the case of the purple loosestrife people went back to the areas in Europe and Asia where the purple loosestrife is native and they found an insect which is as specific a feeder as possible in case a purple loosestrife I mean they actually found a beetle which I think only eats purple loosestrife and nothing else so and also there’s nothing really in our native flora which is very closely related to purple loosestrife and certainly nothing of economic importance so that’s where they always look there are some odd examples i think the Colorado potato beetle is one which I think that that’s example where potatoes were not native they were brought in and yet they were attacked by a species that was here feeding on other things so it’s sort of a reverse of that and the case where I think the row was remarking in 1850 about the that my gosh and littleton few miles away someone shot a deer there was a deer there he

was he was shocked and amazed and the transformation of wild turkeys or in the case of deer of being invasive sort of species now has become pest pests like yeah one attack down man man no I heard the turkey did oh yes yes yes you see them often on the way to work get one other example of how a native species has become an invasive species and that is what is commonly called the corn earworm moth or the cotton bollworm moth this is a moth that’s been is native to the southwestern US its original host where wildflowers and it turns out they still that’s the first generation of hosts that they use but now that there are monocultures of cotton and corn they proliferate in these in these mana agricultural systems and have become invasive and very serious one of the the maz in the world that is the most serious pest of Agriculture I wanted to ask a question about vines well I’m Joan Joan crim Liske I’m an alum of bu and let’s see I vines that if they are cultivated you know they can have a trellis and grapes are quite a large industry but other vines when they cannot stand alone they can strangle other plants and grow so I just was wondering if you comment on those well it’s certainly a you know a class of invasive species I mean I did mention bittersweet for example another one is Japanese honeysuckle screaming crazy kudzu kudzu which we actually there’s a it could be a little bit of kudzu maybe in the Boston Harbor but I mean certainly purple loosestrife is the greatest you know invasive species around here so I mean they they really are out of control they grow up on native trees and and pull them down they have fruits which are dispersed by birds so they can go from place to place if you cut them they Reese prout so there really a terrible problem I’ve actually never heard of any really effective way of controlling bittersweet other than actually just cutting them down manually and poisoning them so very serious problem in this area hi my name’s do you on okay okay my name is Andy Sutton I’m an artist and I have a question for I guess all of you I’m interested in the tying some of this conversation into the economic political social factors and I’m wondering if there are any instances where there is actually an economic or political or a social benefit that happens in the promotion of biodiversity or of natives or of you know something that’s outside of a gigantic cash crop or yeah yeah but it’s it’s on a different scale I’m sure Richard will want to speak to this but one of the one of the mechanisms we work with the organization called Conservation International and one of our primary tools is the development of natural products so for example in coastal Brazil in the Atlantic rainforest it sounds it sounds unlikely but the production of honey from native bees that live only in the rainforest is one of the forces that’s helping to preserve the tiny little fragments that still remain and there are a lot of examples of that I mean in marine environments there are like the the curio trade for seashells could be sustainable and then you need to have the whole reef in order to in order to have any seashells so there there’s a whole literature on that i wish i wish i could say it could hold the candle to like Cargill and those guys but no Richard Richard well I’m just going to pick up on the comment about bees honey bees are not native to North America they were brought in hundreds and hundreds of years ago I don’t know anyone who considers them to be invasive species but they sort of would fit the bill partly but yet those that have been bred with slightly different traits they’re still honey bees the Africanized honeybees are considered villains and invasive in areas they’ve moved into but that again is a judgment call for those beekeepers that are able to cope with the Africanized honeybees there oh they’re absolutely a wonderful resource they get up earlier in the morning they fly later and under poor weather conditions they work harder

yeah yeah we just don’t want them in our own backyards such that’s the issue so yeah these are a good example something that’s been exploited good my name is our zoom with a science journalism program I’m wondering when you when you discuss possibly embracing the invasive species is there is there a way to do that by accommodating them in some way so that they don’t push out other species well i would say that when you accept the native species is being appropriate for a circumstance i mean you have to make sure that they don’t go on beyond that into the into the native of areas or into national natural protected areas so i think that that’s you know one of the concerns there you can see an example of the difficulty of doing this at the Arnold Arboretum at the Arnold Arboretum they grow huge numbers of non-native species some of which have the potential to be invasive if you go into the surrounding properties the surrounding forest areas around the Arnold Arboretum you can see that they’re often there are these really strange weeds growing in the woods or the edges of some of these for us and the reason is because they are the growing up from the seeds brought into those areas by birds flying from the Arnold Arboretum into those places so they’re just really odd weeds there that you would never find anywhere else in in New England but just in the properties near the Arnold Arboretum because that that’s kind of a focal point for these very unusual species some of which have the potential to be invasive so you have to be careful whenever you’re growing growing up things like that Botanical Gardens zoological gardens are historically terrific voci we had two zebras that got out from the zoo and the guys with the hoofs yeah yeah well they you know as far as we know that they didn’t breed and they’re not rampaging down Commonwealth Avenue but a silly example but no those are areas where there’s great risk of escape so at what point do you decide to do something about I think you have to decide first as to what is an acceptable level of intrusion into the environment what is the the economic or public health or other harm that might come of these things and at what point does it make more sense to take action it’s a very delicate balance and not necessarily any right answers that people are going to agree on okay can I take issue with that sure okay I think actually the situation is one where we’ve unleashed a lot of dis regulating forces by moving species around and actually it’s up to the younger people in the world in the world in the room I can cop out now a job has been forced on you a job similar to that of Adam and Eve you are the gardener’s of the world now you don’t really have a decision whether to tend the natural garden or not whether to give it that slight edge that it needs you need to do that to preserve your options you need to prevent the world from becoming entirely homogenized by weeds if you fail to do that your children will pay the price because an enormous amount of natural wealth is sequestered in these natural systems it’s not that there’s something wrong with weeds a lot of them taste good a lot of them are weeds because they were useful to us now you don’t know what we’re going to be needing tomorrow so I just want to add to that also that we’ve mostly talking about plants in terms of plants becoming invasive but actually what one thing which continues to impress me is how many fish and aquatic organisms are moved around the rolled in the very strange and so we actually supposedly like after I guess Hurricane Andrew or various other Achaeans hit Florida all these aquariums both commercial aquariums as well as the aquariums and pals houses just washed out into the Illinois I know where you’re going with this and so one example is there’s lionfish right now which is this ornamental fish which is del just devastating apparently a lot of the ecosystems sort of off the coast of Florida and that’s because of people like you know you want to know the irony of this the irony is when Hurricane Andrew hit I was hoping that all the lake victoria cichlids that were held in facilities in Homestead would get loose and populate Florida and they fail in the littles the leaks in Florida yeah not the ocean no the lake the lakes there but they failed I mean we had 200 species here and and they were a

complete disappointment I was wondering about your comments surrounding even just identifying what’s an introduced species you were mentioning that you saw potential for a plant to explode yet the politics aren’t there to try to control it the cane toads in Australia they wanted to put up a two-million-dollar fence to prevent them from women territory that they were not considered actually taking any other animals meat and then on the other side of it he were to look knowing like Yellowstone area with the introduction of the wolves that are really putting ship as a top predator taking a lot of food from the grizzly bears that are now going into camps and we’re being a lot of their tents I had not heard this attributed to wolves but consider you know environmentally impacting as well as economically with the ranchers and such so I’m wondering with the controversy issues of the wolves they’re not really being considered as an entry species but there by what you outlined before dr. Park might be qualified that the cane toads are not qualified as an entry species or invasive species sorry so curious about political agendas and controversial issues and your ideas on that how that would impact man’s participation well let me just clarify one point the definition I read is is one of the federally recognized definitions of an invasive species if there are depending on which agency of the federal government you talk to you you’ll get a slightly different definition so just because it doesn’t necessarily impact a human health or our economic situation doesn’t mean it’s not an invasive species it’s also it’s it is intriguing why the society mobilizes against certain species I think it depends to some extent on publicity and and charisma and who the leaders are and what the characteristics of the species so in Newton for example is just where I live there’s just huge interest in getting rid of Japanese knotweed so I think it’s because it’s very easy to recognize it’s very distinctive it also sort of feels good when you rip it because the kind of the stem snaps in a very kind of satisfying way when you rip it out so i think that people like to get rid of it it’s also kind of big plans so it’s kind of again it’s kind of easy to go after and we’re very good to organize school groups to eradicate japanese knotweed whereas purple loosestrife is much more difficult to eradicate for example now i think that it to some extent to the squeaky wheel that gets the money if you can demonstrate a real economic harm then your elected officials are more likely going to pass some sort of legislation to put money towards doing something about it so as evidence of this well again there’s an article in the local paper today about the long the Asian longhorn beetle that it’s been found and yet another community a little further the infestations a little more extensive than had been expected there’s a lot of money going towards trying to search detect and destroy these things I think one argument is at what point is it going to be in five years 10 years 20 years that someone’s going to say well we’ve been spending money on this from X number of years we still have them do we accept them or not or do we just keep spending money on this well we spend a lot of money to control like measles and measles is going to be here for a long time I mean there are a lot of there are a lot of organisms that are do not find favour with us and and we want to create an environment where they are rare even if you’re not going to completely get rid of them but I mean well you’re citing ational longhorn beetle has enormous economic and emotional impact where it appears what strikes me as interesting is that we do have a focus on Asian longhorn beetle which I think it’s justified I don’t think the state of Massachusetts has a coherent plan for the restoration of old-growth forests we only have places where trees are growing but I don’t think we say we have any places that say this will be left alone for 400 years because that’s how long it takes to restore the biodiversity of an Eastern deciduous forest so I advocate policies of getting rid of longhorn beetle even if it’s impossible to completely eliminate it but it has to be balanced doesn’t it with some kind of

vision of what you do want and some kind of energy put in that direction let’s take one more question we want to we want to win a close and fine good point of closure we’re a couple you have mentioned poisons and so I want to ask about poison ivy as a natural poison and is there a purpose or a reason that it appears and then is it do you have to fight a poison with another poison well I mean poison ivy is a native species but it’s a species which obviously has benefited from disturbance it’s what grows very well along roadsides it probably is able to take up nitrogen but you can’t really use it to fight other vines for example it doesn’t work I would say it’s almost you know an example of a species which is almost invasive within its within its own range but you can’t really use it to fight other vines and use it right the lemurs well actually another interesting thing about poison ivy is that poison ivy is one of these species which seems to also be thriving under higher co2 environments so there actually have been some laboratory experiments which suggests that that with higher co2 levels it’s actually stimulating it to grow to grow more and also certainly with higher nitrogen levels yeah kill poison ivy walk well that’s draws to a close with just a couple of comments first of all thanks to our to our guests you