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Tópico em 'Biosfera e Atmosfera' iniciado por FSantos 20 Jul 2010 às 22:33.
No Parque Biológico de Gaia é exactamente isso que tem sido feito.
Não creio que abater todas as árvores de uma vez e replantar tudo seja uma boa ideia mas trocar rapidamente essa árvore, que destrói o solo, por outras muito mais características de Portugal parece-me, além de uma excelente ideia, uma obrigação.
Voluntarizo-me para a reflorestação.
Se alguém conhecer alguma iniciativa que pretenda reflorestar a serra do Marão, também gostaria de poder ajudar.
O mais grave é que estes eucaliptos que existem aqui nos arredores do Porto, na sua maioria, não são para a produção de pasta de papel, estão apenas a ocupar baldios, bermas de estrada, margens de cursos de água... imaginem o que seria se não tivéssemos eucaliptos mas sim carvalhos, a diferença paisagística no Outono ou no Inverno!
Em relação ao Pinus pinaster (Pinheiro Bravo) é uma espécie nativa mas foi plantada em muitos locais onde nunca o devia ter sido, em detrimento dos carvalhos e outras folhosas
Há metodos para controlar estas pragas: Acacia dealbata, Acacia melanoxylon e Eucalyptus globulus.
Soy contrario a esos metodos quimicos. Afectan as aguas, as aves, aos mamiferos pequeños como raposos, as plantas autoctonas, afectan a tudo.
Penso o melhor e que a poboaçao arranque as cando vejam esas plantas no monte.
Li há uns tempos que a indústria do mobiliário poderá dar mais emprego e riqueza que a indústria da pasta de papel. A proposta seria apostar na plantação de pinheiro-bravo, mas também de carvalho.
Consta que estamos a importar madeira de pinho da Espanha ou de França, e da madeira de carvalho já nem se fala, passámos de exportador no passado para importador. Nunca houve uma política de protecção e reflorestação em relação ao carvalho-roble, ao negral, ao de Monchique e ao cerquinho.
Por motivos de ordem económica sei que é impossível voltarmos a ter o país todo coberto de vegetação autócne, mas já seria óptimo se houvesse um maior número de hectares de matas nacionais ou parques municipais cobertos de vegetação natural.
Well, sorry, in English. Now I don't want to be the devils advocate either, but there is no need to do so. I have done my research on the topic of exotic species thoroughly and I am currently writing a book on it. It is difficult where to begin.
Let me start with the scientific rigor of ecology and their job (ecologists/biologists), which is to obtain unbiased data withtin their field of study. A overwhelming majority of ecologists do not behave like impartial scientists in this field. For my book, I asked my girlfriend to get me 10 books about exotic species. I had no clue what she was bringing. This served as my own, unbiased test on the language used in those scientific books. Mind you those books are used in Universities.
The following language was a constant in every single book. Exotic species, among which was Eucalyptus, were: a pest, a nuicance, threating, invasive, aggressive, prolific, a plague, injurous, have adverse effects, alien, noxious etc.
All these words are subjective, valueladen and do not belong in any scientific research. In a scientific research, such allegations must be substantiated. No one can prove that something is a pest, a nuiscance, noxious, injorous etc. If I like these species, they are not and therefor this is subjective.
We over here know the Artic is melting and it is melting at an statistical significant rate. That is how you address changes. Whether it is a good or a bad change, depends on your personal stance. No scientist can tell you how you should think about the change, what is (im)moral. A society as a whole has its ethics, which change over time and in space. And a society as whole decides what is needed. Not one scientists or one scientific field. They shoud gather data and let society decide. Not so in ecology: here the scientists say it is in fact their role to judge. Influential ecologists literally say that.
The effect is clear: students on Universities adopt this attitude and so this spreads throughut the community/world. It is a typical, conservative look upon newcomers and changes in general. Changes are bad, newcomers must be scrutinized. What we have is good, what is new is bad. We do not look at what is really causing things we perceive as a problem. That what we know and consider indigenous, is highly valued. It is in fact bordering on xenophobia and it is difficult to keep an open mind, once you start reading the literature. That is what indoctrination does.
Now, not all ecologists work along these lines. About Eucalyptus: the same story was told to students in Californai about their Eucalypt forrest. These were ecological deserts best cut down. Untill some students started to rsearch them. The older they got, the bigger they grew. And the more diverse they became, They were rich in plantlife, they were rich in animal and birdlife and they were equaling the longgone redwood forests. No wastelands at all. This example is no exception. Over here in The Netherlands, the same is told about various coniferous forests that do very well. We have some natve conifers and some that are questionable (Norway Spruce, which rejuvenates very good). Those forest are cut down and formed into...heath..
First of all: we have Sitka spruce forests where 23 of 27 of all fern species grow. Not just grow, they do so extremely well. They are in fact only comparable to their NW Pacific "natural" counterparts. Many species are redlist species, but they are cut down nevertheless. Under Norway spurce canopy and soil, funghi do very well. Many red list species depend on them. Yet, they are cut down and transformed into heath...Heath is not a landscape that can exist without human interference. And so we have double standards.
It goes even further...they ar enow planting purebread Dutch Fagus trees (and all other trees) as imported ones from Norhern France are genetically different. And when confronted with remarks by some this seems like ecofacism, they get very aggitated. Right...
But more importantly, in England native oak and pine woodland have been compared in biodiversity (which is becoming a dogma) with Norway and Sitka spruce stands...The outcome was, totally contrary to the firm belief of ecologists and natureenthusiast alike, that the biodiversity in all these forests was equal to native forests.
These examples are not the exception, these examples are the rule. To summ it all up. Peerreviewed scientific research has shown that on continents, exotic species do not cause extinctions, Plants never do. All reported cases have reseachred by Dov Saxm Steven Gains and James Brown. It has been published in PNAS, a highky regarded paperon the topic and it has not been denied either. Extinctions occur, rarely on continents but sometimes on Island like habitats like The Pacific, Lake Victoria and the cause is disease or predation. Even there, on those Island the story is not single sided. In almost all cases the species lost were already in decline well before any alien species arrived. In all, local diversity rose enormously. New Zealand: had 2069 native plants, received 2065 newcomers that became established and lost the "grand total" of 4 species...Yet again: the rule. In Europe we now have: different kind of squirrels, American Mink, Tsuga, Pseudotsuga, American Oak, Sitka spruce, Eucalyptus, etcetc. The fact is we get more biodiverse because of this. It is like counting the Portuguese population and say it is 8,2 million....8,2? Yes, all immigrants do not count...??? It is simple: worldwide bidoiversity declines, locally it rises. Fact.
There are mass extinctions and personally (I love nature, I am in it many times for photographic purposes) I dislike it. But if we want to change it, we must start with what IS without any doubt the cause. for loss of species. It is habitatloss, hunting and polution. It is our consumption of meat that means we cut down the Amazon and Indonesian tropical forests which are immeasurably more biodiverse than any temperate habitat. Our need for wood. It is also habitatloss in Europe, Asia...anywhere. Not because of exotic forests or animals, but because of cities, farmland etc.
Like foreign people, exotic plants and species are the scape goat. When one fingerpoints to them, three point to us...
In the end the world is changing. Fast. We see cultural exchange at an enormous rate. Would you say Portugal or Europe is now culturally poor compared to 100 years ago because we lose some of what was considered typically Dutch, Portugese or whatever? Do we want to go back and only eat Portugese food, Portugese music and share our soil with purebread Portugese people? Do you think it is okey that even if you think so, you can wipe out all things that don't suite you?? Are there no ethics?
Because that is what happens in nature nowadays...the homogenisation of the Earht biota is considered BAD. If we count biodiversity we only count what was in a place before newcomers came. And we want to go back..guess what happens to the newcomers (animals especially)..I think it is not bad in culture and it is not bad in nature. I think it is a conservative, unethical goal that will cost billions because there is just one big problem: we cannot accept change in nature. We despise those who feel the same when they propose similar tactics towards human foreigners or human foreign elements in culture but are blind when it comes to our own stance in nature.
I end my rant here.
But what is natural. Is importing things not natural? It is what humans do and have done so. Natural does not equal "'good". By using "natural" people have tried to say somehting was good or bad all the time. Like homosexuality...that was "unnatural" and therefor "bad". While those people just experienced love for the same sex. Or the British Natinal Party, who had an add on the BBC in which as Sikh said "nothing wrong with the BNP, they try to protect the brittish people. In India, we do the same..it is only natural...
People transporting things all over the world is nothing "unnatural" it is natural. The spread of species over landbridges and seabridges (so to speak) has happened and has never had an adverse effec on the number of total species. If people say that currently that number has risen is one thing. To say it is unnatural and there for (in the end) native forests are "natural", is unsubstantiated. Where did humans become "unnatural" and why is your interference in purpose in what humans do natural and what those human did (importing species) unnatural?
Why is it bad? Because the soils changes and, so we get a vicious circle, local species have more difficulty to survive. May be yes, may be not. I have seen and heard about forests in Galiza which are rich in biodiversity also but even biodiversity is not a dogmatic, all good thing.
The reality of the matter is that the exchange of plants and animals has rarely caused an extinction and is on the rise. Yu can single out Eucalytucs, but there ar einnumerous others who'll havetheir own effect. You are trying to turn the tide because you think things are better another way. It will costs you a lot of money, better spent (in my view) not in getting rid of immigrant species but better to address the real cause: habitatloss because ofd agriculture and co. In Portugal and Spain many inland villages have been abondonded. Fine. Do nothing. Cheap and sensible. Not rowing against the stream, but flowing with it. And observe and see what happens, not trying to have it your way and placing your insight above other humans. Because it is not a problem at all for nature, it is a problem only in the heads of humans who yet again try to change things with force. It is not going to work in the long run. You won't get rid of immigrant species. Even now, in econimical worse times we see the money spent in nature (it is at the end of the econimical bill) has been reduced drastically, so many goals are not achieved already.
Besides: I see nothing good in getting rid of species because they don't do what some people like. Not at all.
I understand your point, J.S., the same can be applied on global warming...some scientists have ideas about putting thousands of small mirrors just off earths atmosphere, to block solar income and reduce temperatures...without considering the side-effects on photossyntetic organisms or even the atmospheric padrons themselves.
Propagation of species troughout the world is something that has always happened...the difference now is that we are ( just like the GW) speeding it up.
Now think...GW and extremist scenarios ( some of them tottaly impossible and non-realistic..) about sea rise may not be so harmfull to earth as thought...is it that we consider bad only what is bad to us, humans?
GW may be excellent for multiple species, and increasing C02 can be a way to avoid natural ice age phases, wich are quite traumatic to earth´s life..
My idea is that, now that we have the knolledge, we should be more carefull about interfering with natural processes and we MUST stop deflorestation an pollution, but when trying to reverse what we´ve done wrong i think its better to let them reverse themselves rather than try miraculous cures..
As its said here in Portugal, there´s the risck of dying of the cure instead of the disease