Hot answers tagged ecology
16
The conservation biology literature has a great deal of information, particularly with reference to developing species survival plans (e.g., Traill et al. [2007] report a minimum effective population size of ~4,000 will give a 99% persistence probability of 40 generations).
Because the question specifically mentions human populations, I'll focus my answer ...
15
A hormone is defined as "a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism" (I'm just taking Wikipedia definition).
Hormones work by binding to specific receptors present on their target cells so, if there is something in the environment that mimics the hormone, by ...
13
There are several key ways in which rising atmospheric CO2 concentrations will affect photosynthesis, and these are related to the different types of photosynthesis. In order to properly answer your question, I'll provide some background about photosynthesis itself.
Photosynthesis evolved in a high-CO2 atmosphere, before the oxygen-enrichment of the ...
12
While poison affects not every organism equally, plants did develop some poisons to avoid being eaten. However, if you look at the great multitude of so-called secondary metabolites, most of them are poisonous to either viruses, bacteria, fungi or other microorganisms, or insects, or even other plants. Plant evolution just hasn't had time to adapt to humans.
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10
I wanted to add a little more to the excellent answer above, especially since the OP asks about research into this question in a "real-world context".
There is a substantial body of evidence on exactly this question that comes from experiments at "Free Air CO2 Enrichment" (FACE) sites. FACE is an experimental method/technology in which standing ecosystems ...
9
Population dynamics occupies a whole subset of mathematical biology. Perhaps the most pragmatic uses for modelling population dynamics come from the fields of epidemiology for modelling disease infection and transmission through a population (one such article), or ecology modelling things like forestation, fishing dynamics, predator-prey relationships (an ...
9
I did some research on the topic and came accross this paper by Johnson et al. I am not a zoologist, so everything I write here is taken from the references paper.
The authors used genetics to estimate gene flow between different populations of limpets Lepetodrilus fucensis which is considered to be an endemic hydrothermal vent animal. They used a ...
8
Following up on Alexander's response, I read a little more on the subject by looking at some of the references in the Johnson et al. paper.
This paper discusses an interesting case where researchers could study a hydrothermal vent ecology before and after a catastrophic eruption giving a "natural clearance" experiment. Since endemic organisms were ...
6
Two previous answers listed many applications of population dynamics models. I want to add that they are also important for conservation of endangered species. For example classical stage-class model (Crouse et al 1987, free copy) indicate that the most effective way to protect sea turtles is reducing mortality of large juveniles.
Moreover, you don't have ...
5
Leonardo's already given you an excellent answer, but I thought I'd add my perspective. I'm a mathematical epidemiologist, so I'd at least like to believe these types of models are useful.
For me, there are a number of things population dynamics models are especially useful for:
Highlighting data requirements. Yes, models need data, as you've mentioned. ...
5
There does not appear to be a current standard, but Veg-X is a standard that has been developed to facilitate exchange of plot-based vegetation data, and may provide the closest to what you are looking for.
Veg-X is described in Wiser et al 2011 and the project home page is http://wiki.tdwg.org/Vegetation/
From the abstract:
The exchange standard for ...
5
I guess you meant the population size stability.
It is considered that the biosystems will increase their capacity of adaptation when evolving in very fluctuating environments. I believe the population stability is embedded in the adaptability of individuals.
There is a measurement about it, evolvability, when the environment changes, the faster the ...
5
Barring the very obvious surfaces (the pits of active volcanoes), the only place I'm aware of that might not contain life is the Atacama Desert near the Andes Mountains in Chile and Brazil.
Whereas other places that seem inhospitable - Antarctic, Hot Springs, regular deserts, extremely high altitudes, etc. - the basic necessities for life still exist ...
5
That will depend on many things. How do you define surface? Is one meter underground still "surface"? How about a kilometer?
Also, how large an area are we talking about? You could probably find a square millimeter in, for example, Antarctica that has no organisms. I don't think you would find a square kilometer with no organisms though.
There are ...
5
There are many websites which describe this phenomenon. They all seem to confirm the basic premise of the question: in tropical rain forests most of the minerals are held in the biomass and rapid decomposition contributes to the recycling of these nutrients for new growth. One example is here.
Tropical rainforests are noted for the rapid nutrient cycling ...
5
I think it does make sense - with a population density for finland that is so low, the disease with such a low beta cannot communicate to enough people to propagate.
The number of people who have this disease will be fewer each week. I think this makes sense because at 16 / km^2, you can expect that practically nobody will ever see each other.
This is ...
4
After talking to my teacher, he said that biological control is the introduction of species to control another species, however species may be introduced for other reasons (the "Introduced Species" method), such as to "assist an ecosystem cope, flourish or re-establish itself."
The example he gave was the introduction of South African veldt grass to ...
4
I'm not an expert on Shannon-Weaver Index, but according to wikipedia it is the same as exponentially transformed Renyi entropy. If it is the case, you can compare them since they are scale invariant summary statistics. If you want error bars, you can always try resampling methods such as bootstrapping. Hypothesis testing can also be done with bootstrapping, ...
4
In an environment where all plants are resistant to certain parasites, a rare breed which has a mechanism against this resistance has free play - lots of food and no competition. However, in plants which do not have the resistance, this rare parasite breed may be at a disadvantage compared to parasites who do not have the mechanism against that resistance ...
3
Both are measures of carbon fixation rate.
RuBisCO activity specifically refers to the rate at which the enzyme RuBisCO fixes carbon to RuBP, and is measured by isolating the enzyme from tissue samples and, usually, using radiolabelled CO2 to measure how much carbon is fixed in a set amount of time in controlled conditions and with controlled supply of ...
3
There are a bunch of possible answers;
On my own property I have such a line. Turned out it was an old fence line. One side was farmed intensely for 90 years, the other side left in bush. The farmed soil is enough different that it doesn't grow good trees. Even the grass is different.
Another place I have an abrupt line of willows. That one turns out ...
3
This has been tried and it sorta works.
Algae in general seems to be inhibited by rotting barley straw in the water.
There is also an observation (not universally accepted) that many plants in the water do not have as much algae. This post is from April 2011, so it seems pretty current.
2
Biological control does not have to be with an introduced species. It can also be accomplished by either artificially inflating the number of existing predators.
E.g. Spruce bud worm has a natural predator in the form of a tiny wasp. But budworm can spread through a stand faster than the wasp can. By moving popluatins of the wasp to the forefront of the ...
2
I think you may have covered the answer in your question... but here's my take;
The 'mowing' occurs at a distinct time-point and is highly destructive and uniform, so the selection pressure is very high and only highly competitive species that are fast to grow and reproduce will be successful.
As you point out, animals will defecate and naturally fertilize ...
2
It sounds like you are interested in beta diversity which is the change in taxa composition (i.e., alpha diversity) between plots. There are a number of approaches to calculating beta diversity and the correct choice generally depends on the question(s) you are trying to answer. The most common approaches are very well described in this paper:
Anderson, ...
2
Take a look at Field and Laboratory Methods for General Ecology by James E. Brower, Jerrold H. Zar, and Carl N. von Ende.
If you are only interested in plant sampling techniques, an great resource published by U.S. Bureau of Land Management is Measuring & Monitoring Plant Populations by Caryl L. Elzinga, Daniel W. Salzer, and John W. Willoughby.
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2
There was actually just such an article in Nature recently.
"They don't occupy an unassailable niche in the environment," says entomologist Joe Conlon, of the American Mosquito Control Association in Jacksonville, Florida. "If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse ...
2
This is a prototypical case of evolution by natural selection. Any trait that prevents the organism from being eaten or destroyed will probably make that organism more likely to reproduce* than similar organisms that do not have that trait**. This results in self-preservation traits becoming more prevalent in the population and eventually ubiquitous.
* Or ...
2
Well, first of all 812mm is a pretty precise value to be preceded by the word "about". "Mildly hot", on the other hand, is too vague a term for your question to be answerable. If you update your question with better parameters, you may get more helpful answers.
In any case, according to this page, a tropical savanna has mean monthly temperatures at or above ...
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