Interesting topic. I live in the country (in Tennessee - so this is a Southern story), so I don't have neighbors to fight with on this issue, but I do know a little about trees and the health of forrests. On my own property, I am preparing for some selctive logging and thinning of the forrest. This is necessary because the old growth in some spots has gotten to the point of causing a DECLINE in bio-diversity. When you get trees that are 100+ feet in height, they can shade out just about anything else underneath. So shade-tolerant species are the only ones that can grow under the canopy, and they eventually create somewhat of a monoculture in the forrest. When the large canopy trees do die - as they all will - what's left are the shade-tolerant trees, and they prevent the next generation of hardwoods from growing. So eventually you loose the majestic Oaks, Hickories, etc. and are left with little more than Beech, Ironwood and Maple. These trees are not as good for the ecology, and don't provide much food for wildlife. Oaks and Hickories are the back-bone of the forrest, providing the lion's share of the food crops. An Oak tree also processes twice as much CO2 as a comparably sized Maple. But their seedlings are shade-intolerant. The Oaks will not grow back if the forrest is shady. So, if we never thin the forrest, and insist on preserving all the mature trees, the richness of our ecology declines. The forrest supports fewer species, and weedy species gradually become dominant. We have eliminated much of the natural "turnover" that occurred in the forrest, especially wildfires. We put them out with a vengence! Yet these acts of nature are crucial to clearning areas where Oaks and Hickories can sprout and thrive in the sun. The Forrestry service did a survey of my land for me and recommended selective thinning to allow a greater diversity of species to grow here. I'm negotiating with loggers who use low-impact logging techniques, such as the use of mules to haul out the logs, so as to minimize the impact on the land. No one loves trees more than I do, but we all need to realize we have a responsibility to manage the forrest, just as we would any garden. It IS a garden - just a garden of giant plants! Diversity and renewal are an essential part of any healthy ecology. I think those principles extend to urban neighborhoods and back yards too. :-) K4

Ah..a political agenda? What kind of a political agenda would that be? Regardless, let's not get ad hominem. Useless. Let's stay on topic. If you read climate research, another kind of global change that evokes strong emotions you will rarely if every come across judgmentality. Whether warming is good or bad is not proven. you cannot do that. However: what you can prove is that global warming is antropogenic. Caused by humans. You cannot prove it is unnatural. What people think about it, is not up to a scientist. It is up to themselves. I don't like it at all and am all for action. The facts here are very clear. Within the climate research, which can be found in nature and Science, there is no doubt. The same cannot be said when it comes to invasive species. There is ample peer reviewed research, done by ecologists themselves, that shows what I say. The lithany of judgemental and value laden wording does not have any place in science, yet it is almost a constant in ecology. And it has a strong influence in the perception of people to what is simply a living organism and at times, a sentient being. I have read many scientific research on it and my point is precisely the opposite: I think most people are simply reiterarting what they have been hearing time and time again without reading on the subject. Niot from outsides, like you see in climate sience, but ecologists working in the field. What bothers me is that this ideology has all the signs of what we see in human culture. That the ideal of some system is worht more than life. That individuals have no value, have no meaning and should be killed. This also has a strong aching to what we see (and tend to fear and despise) in antisocial people, who fail to acknowledge that other people matter, have intrinsic value. That other people have rights, emotions and feelings. Hence extreme antisocial people kill people without a second thought and do not mind one bit. I have seen this been propagated in nature towards various animals. And they are sometimes killed in the most painfull way imaginable. Like the GRey Squirrel in the UK, which is killed by using warfarine so it slowly dies a painfull death from internal bleeding. An alternative is clubbing the pups and, if they ca catch thhem, their parents to death. That is what extremism and hatecampaigns can do. Another thing I have seen in Scotland when I was there and in The Netherlands is the propaganda that is genetically inspired. The Scottish Red dear, which is not a subspecies at all and is not threatened in any way worldwide, is now at the "threat" to be mixed with Sika deer. They have fertile young, which do just fine. Seem happy. Nothing is wrong. But the Scottish Landscape Trust (or what is called) says that "pure blood" Scottish Red Deer are at the verge of extinction. There is nothing wrong with the mix, the calfs are not sterile..Nope. But they have no rights and need to be killed. Wrong blood, wrong place. LEts shoot 'em... In Nl there are quite a few who want to use pure Dutch Beech trees which seeds have been selected an stored, to repopulate the country. Foreign beech trees are no good... The White Tail Duck and the Ruddy Duck have fertile offspring. They are as dissimilar as blacks and whites among people. Yet the Ruddy Duck needs to be killed, because the White Duck would be extinct. And it is unnatural. However, a passerine is naturally hybridising in Europe now. That is okey, it is nature... Now I do understand these are extremes but they are the direct result, again like we have seen in culture so many times, of the thought that nature should be pure and that bastards are no good. Foreign species are somehow worse than native species and need to be eradicated when possible or when they threat our ideal view of the world.... So to me, saying that native is somehow better than nonnative is not as innocent as it looks. I find it very strange actually. I think a species is in its place where it can survive on its own. It seems well adapted, at least for some time, to the place it now occupies. Ceertainly in times with rapid change (climate change) an inflexible attitude towards these seems not feasable. If climate change starts to shift climate zones more and more, you might end up with nothing or very little native things that can grow where they used to... Native and nonnative is a dichotomy that has no meaning in the natural world, only in human culture. It puts evberyhting in a historical context and not in a contemporary one. It seems to be aimed to freeze thing in atime (the past mostly) and on many occasions involve the killing of sentient beings on massive scales as it devaluates their lives based on their origins. and on may occasions without any sight on some final result. Finally, it also puts makind in the position to decide what should and hsould not live somewhere, again making nature and the natural world dependant on us and at times halting processes continuously. Like the spread of Juniperus virginia to the prairie or Pinus sylvestris in NL to occupy the heath again. As this is a continuous proces, this kind of management (which is certainly not unique) means large areas are dependant on economy. If economy fails considerably and there is no more money for maintenance, all the work to keep the landscape in some personally preferred state was in vain. That is my gripe with this. I find it unethical at times, not based on natural but human preferences and strongly based on prejudice rather than facts.

Hi pineresin, Long story and last one here, because I do not want to hijack this thread... No these people are nice people, they in general totally against cultural xenophobia. They are not bad people and quite likable in general. But they in general seem to be blind for their xenophobic views and dismiss them immediately. I have read 6 books, chosen by my girlfriend (blind test) with the subject�nasive species". So I did not pick 'm. These are books meant for Univerity ecology/biology students. All these books are ridden with valueladen wording. At the end, it will be hard not to think of immigrant species as villains, pest, aggressive beings etc. You are indoctrinated in this way, like we can be indoctrinate din so many other ways. This psychological effect is ture for everybody, it is not that scientists themselves are not affected by this. And so it goes...these people find labour in various nature conservancy associations etc. And so their theory becomes practice.. In our Dutch naturereserves you find all sorts of sgns and explanations. In many instances, you read the simplified version: we cut out spruce and pines because they don't belong here because they are foreign". The University of Wageningen has done some research on what people think about foreign species. In two ways. One was to ask about what they think about foreign species and cutting them down because they don't belong here. Answer: 65% are totally against. They were surprised that after explaning (wrngfully!) that they weed out other species and cause extinctions, still the majority did not buy it. Especially Doug fir was highly valued. They thought that broadleaves would be nr 1. They weren't. More on that in a moment. A second one was to evaluate 200 woodland pics. They choose pics with clear foreign species, clear native species and a mix. End result: 4 woodlandtypes were highly valued. The top 2 consisted of a broadleave (beehc and oak) and in both cases a spruce tree (by some not considered native).. So....who are ecologists doing it for? Not for the Dutch people. Not for nature. If nature has anything to say some species simply don't grow somewhere and others do. Not because trees and plants cause extinctions. Well... they think so everstill, but peerreviewed research shows they don't. Even in those books I mention you can read this in between lines. The do not emphasize did, but in those book they stated that not one foreign species ahs actually led to extinctions. And then: "until now" implying that this will probably happen or is likely to happen. It hasn't. So what does Wageningen Uni want to do? DO they want to change their views..nope. Their goal is to change our views. They clearly concluded that other approaches need to be developped to make people change their views. This again comes close to some propaganda in the cultural sense. In the UK, you see they want to weed out Pinus contorta and Picea sitchensis of the Caledonian forest (Scots pine). Which is "unique" (also another words that has no scientific meaning as so many things can be called unique). Now why is Scotspine a threatend species? No: it is the most widespread conifer around the world. It is the Scottish crossbill, a bird in that forest only found in Scotland. Okey, sound plausible. But the Crossbill is happy to feed on contorta. even more strange: waht makes this bird so special? It s colour? No? Does look different from the two other crossbills in that area...No...They in fact fligh in the same flocks with all others, you cannot distinguish them. So what is it? It is the song. It has its own song...so that is a good reason the set it apart and to weed out all sorts of nonnative species apparantly. Etcetc. If biodiversity is the main reason and it cannot be local biodiversity (because our local biodiversity has gone up much by all those foreign species and not too much loss of older species). Biodiversity is global, according to them. Scots pine is not at risk. Nor is any other species in that area of any concern worldwide. Why spend so much money in your scottisch forest, while you would do A LOT more for global diversity if you would spend that money to protect the Indonesian rainforest? The fact is that ecologists and conservatist use biodiversity as a reason, but their main goal is their own nation. Not global biodiversity. Finally: it seems to be a big problem that the Ruddy duck intebreads with the whitehead duck. They however get fertile offspring. Besides: genetic swamping has never let to the demise of any species. The Ruddyduck and the Whitetailduck are no more different than black and white people. They are the same species. But in ecology, basic human things like discrimination have not the proble of being considered morally incorrect. So even so, we must kill the Ruddyduck at sight to keep the whiteheadduck (whitetailduck??) genetically pure. Where did we read that before. Another final example is the Sikka deer, also in England. It interbreeds with reddeer. Is the reddeer at threat wordlwide? It is not. do they produce fertiel offspring? Yes they do. So if anything, you get another species. A new species. But that is not okay: the reddeer must nbe kept genetically pure. The Sikkadeer must be shot a sight. I think ecology is a good showcase how people can think basically when confronted with newcomers and strangers when they do not feel the pressure of morals. They tend to be prejudice, act on their prejudice etc...This is also our nature. It shows that nature and natural do not equal good and unnatural equals bad. We do not need to judge., However: it is the people at large and not some scientist who decide what happens in a countyr and what not. If I tell these examples to people, they find it totally unacceptable. The only ones who do, are ecologists and co...

That is an excellent piece of the puzzle KT. It fits with the likely consequences of shifts in vegetation patterns due to warming at the end of the Pleistocene period and inability to adapt to shrinking habitat. Researchers in Australia recently revisited Darling Downs. This is what they found: "By systematically analysing a 10 metre deep section of creek bed, the team uncovered 44 species, ranging from land snails, frogs, lizards and small mammals to giant wombats and kangaroos including many species previously unknown to have occurred in the Darling Downs fossil record. The results suggest that the extinction of Darling Downs megafauna was caused by a massive shift in climate rather than by the arrival of humans who over hunted animals or destroyed habitats by burning the landscape. The findings, which were unearthed with the help of amateur fossil hunter, Ian Sobbe, are of particular significance because the Darling Downs fossil deposits are among the youngest Australian megafauna deposits - laid down on the cusp of the extinction event. [snip] The Darling Downs contain some of the most extensive and significant Pleistocene megafauna deposits in Australia but because it's been excavated since the 1840s it was assumed that the palaeoenvironment record was well established. Closer examination revealed a bias in sample collection in favour of larger animals and there had been few attempts to document ecological and sediment data." See link for full text. The N.A. overkill hypothesis doesn't account for the birds lost at the same percentage of the megafauna. Who knows what else that may have been overlooked. Even more suspect is the fact that Martin's theory is based on the land bridge hypothesis which isn't supported by any evidence, yet has become gospel. Here is a link that might be useful: alert