What are the main drivers of soil microbial diversity?
117488
Each of the microbes performs a limited number of tasks (so to speak) in maintaining soil structure; some of the tasks are, I suspect, mutually exclusive of others...\n\nIt is actually impossible to be sure why there are so many diverse organisms, beyond that: we weren't there when the structure was put together, and the best we can do besides make this humble observation is make scientific, wild-eyed guesses based on whatever theory we prefer...
757663
Microbes break down materials by using them as nutrients for their own growth. In the process, the materials are reduced to simpler molecules. In a sterile environment, nothing would decay, only desiccate (dry out).
535384
The paddy soil-rice system has efficient nutrient replenishing mechanisms. Basic cations and silica are supplied by irrigation water, while biological fixation works as an inexhaustible source of N in the system, and phosphorus availability is enhanced under anaerobic conditions. This, along with almost perfect resistance to soil erosion, gives the paddy rice system high productivity as well as high sustainability.It has been shown that of the three essential macroelements, two of these, K and N, have an assured, if not sufficient, supply mechanism in paddy soils.Phosphorus has no such supply mechanism. However, it is the 11th most abundant element in the earth's crust, and is present everywhere in the soil in reasonable quantities. Therefore, what matters usually is its availability rather than the absolute quantity present. In acid soils in a humid climate, P is present mainly in the form of iron phosphate (Fe-P) and aluminum phosphate (Al-P). Neither of these is readily soluble. There are, of course, organic forms of P that may be released during the process of organic matter decomposition. However, in contrast to N, the quantity of such organic P compounds is normally very low, compared to the mineral forms of P.In the process of anaerobiosis in paddy soils, iron phosphate tends to be reduced, with a release of some of the P in available forms. Moreover, reduction of iron oxides releases some of the occluded P into the soil. Thus, there is at least one mechanism to raise the availability of P in paddy soils. The reduction of paddy soils under submerged conditions is accompanied by an elevation in soil pH. This is the result of H+ consumption as oxidized materials, such as NO3- and Fe2O3, are reduced. Usually the pH of acid paddy soils stabilizes at around 6.5. The rise in pH enhances the solubility of iron phosphate and aluminum phosphate, by a factor of 10 times per unit rise in pH.
280929
Tundra has low diversity (only 23 different species are plentiful there, 16 of which are in the same class)\n\nConiferous Forests and tropical regions have enormous diversity
687109
Paraphrase: "Most pseudomonads are free-living saprophytic organisms in soil or water where they play an important role in decomposition, biodegradation, and the carbon and nitrogen cycles. Because of this lifestyle, pseudomonads are characterized by great metabolic diversity and are able to utilize a wide range of carbon sources, including molecules which few other organisms can break down. Consequently, they are important organisms in bioremediation."\n\nYou'd do well to google it and actually visit the source I provided below. By the way, what was your motivation to ask this question? Or were you just gaming for points? Be kind, don't SPAM up Yahoo Answers.
825715
Bacteria are involved in decomposition, fixing Nitrates into the soil and digesting plant matter in the guts of herbivorous animals, for starters. Without this crops wouldn't grow, animals couldn't eat them and dead bodies wouldn't break down.
810788
They've got the starring role! Bacteria, fungi, protists, all of them pick away at whatever dead matter they find, and the important thing is that they often secrete digestive enzymes onto the stuff so it breaks down. This helps them have small food particles to ingest, and it cleans up the environment to boot.
230027
Diversity is a term that refers both to the different classes of items in a given system, and also to the distribution of those items in those classes.\nBiological diversity or biodiversity is related to the concept of biocomplexity, that is, the web of interelationships and fluxes circulating in the ecosystem. It is usually measured at three levels: ecological biodiversity, species biodiversity and genetic biodiversity.\n\nSpecies biodiversity is not only the number of species in a given ecosystem, but also the proportion of individuals that belong to each species. \nExample: \nIf you have 10 species, but out of a 100-individuals sample, 91 belong to a single species, then the biodiversity is not that high. In probabilistic terms, you  could say that the chances of finding 9 of the 10 species in any sample is low. \n\nThe rainforests of the world are classical examples of high diversity ecosystems. In contrast, most ecosystems that are under continuous stress are less biodiverse, for example deserts, or grasslands. However, low biodiversity does not necessarily mean "less healthy" ecosystems. Although a grassland is less biodiverse than a rainforest, it's a stable biome all the same.\nA related concept, ecological biodiversity, refers to the variety of ecosystems in a given area, and the pattern of distribution of communities in a given landscape. No ecosystem is completely isolated from others and the health of each one depends partly on the interrelationships with other areas, therefore, the loss of ecological biodiversity due to the disappearance of certain environments can lead to greater unbalances.\nGenetic biodiversity refers to variety at genetic level. In a population, it refers to the different alleles (variations of a single gene) that are present. We know that evolutionarily speaking, polymorphisms (presence of different alleles) are a sign of a healthy population, because a greater source of variation is a better resource to respond to environmental changes. Populations that lose their genetic biodiversity (for example, because the number of individuals is severely reduced) may be more exposed to extinction. \nBiodiversity can be measured at all the organization levels studied by Ecology, but is especially focused in communities and ecosystems.
825850
Bacteria, amoebas and fungi
613676
If the relation is not intimate as in mycorrhiza as said by skeptic,there are certain fungi which thrive on exudates from roots at it's rhizosphere.So,due to this reason they are species specific.These biochemical secretions are needed for it's growth and germination of spores.
434994
None of them- Tropical rain forests tend to have very poor, shallow soil, but a high variety of trees, plants, and lifeforms, with a great deal of diversity.  So for the first chioce, yes it has a dence layer of plants, but it does not have dense thick soil\nFor the second, it does have many species of animals and poor soil quality, but it also has many species of trees\nand for the third, yes, it has year-round warmth and moisture, but the animals and plants are not 'very similar" (a phrase I dont really understand-similar to what?)
414931
Biology\nEnvironmental Science\nChemistry
355458
The formation of supercontinents (like Pangaea) can reduce niche habitats and reduce species diversity through mass extinction.  There is also some evidence for magmatism associated with continental rifting emitting enough gases to effect the climate.  If you want to know more about huge volcanic flows that could do this, google "Deccan Traps" or "Siberian Traps" (which seem to have occured at roughly the same time as the end-Cretaceous extinction and the end-Permian extinction, respectively).
796104
soil analysis\ncrop rotation\ncontour planting\ngene manipulation\nthe use of chemicals for soil enrichment and pest control\nbetter and more efficient machinery for field preparation, planting, maintaining and harvesting\nbetter and faster transportation between the field and table\nthe use of insects - bees for pollination and natural pest control
73469
This smells like schoolwork so I'll just leave a few leads. \nBiodiversity or biological diversity can be measured as:\n- species diversity\n- ecological diversity\n- genetic diversity\nEach has specific methodologies for conservation.\n\nConservation can be basically of two types: \n- in situ\n- ex situ.\n\nTry the web and also the book "Living in the environment" by G. Tyler Miller. It's probably available in your school library.
1032957
Soil Science An Interdisciplinary Approach to Soil Research, satisfies the professional needs of all scientists and laboratory personnel involved in soil and plant research. The authoritative research articles published in the journal report the most significant work of leading experts from every area of soil and plant science–soil chemistry, physics, fertility, morphology, microbiology, and environmental soil science.\n\nThe pH of soil or more precisely the pH of the soil solution is very important because soil solution carries in it nutrients such as Nitrogen (N), Potassium (K), and Phosphorus (P) that plants need in specific amounts to grow, thrive, and fight off diseases. \n\nIf the pH of the soil solution is increased above 5.5, Nitrogen (in the form of nitrate) is made available to plants. Phosphorus, on the other hand, is available to plants when soil pH is between 6.0 and 7.0. \n\nCertain bacteria help plants obtain N by converting atmospheric Nitrogen into a form of N that plants can use.These bacteria live in root nodules of legumes (like alfalfa and soybeans) and function best when the pH of the plant they live in is growing in soil within an acceptable pH range. \n\nFor instance, alfalfa grows best in soils having a pH of 6.2 - 7.8, while soybean grows best in soils with a pH between 6.0 and 7.0. Peanuts grow best in soils that have a pH of 5.3 to 6.6. Many other crops, vegetables, flowers and shrubs, trees, weeds and fruit are pH dependent and rely on the soil solution to obtain nutrients. \n\nIf the soil solution is too acidic plants cannot utilize N, P, K and other nutrients they need. In acidic soils, plants are more likely to take up toxic metals and some plants eventually die of toxicity (poisoning). \n\nHerbicides, pesticides, fungicides and other chemicals are used on and around plants to fight off plant diseases and get rid of bugs that feed on plants and kill plants. Knowing whether the soil pH is acidic or basic is important because if the soil is too acidic the applied pesticides, herbicides, and fungicides will not be absorbed (held in the soil ) and they will end up in garden water and rain water runoff, where they eventually become pollutants in our streams, rivers, lakes, and ground water.
76491
Depends on the soil and what chemical process was used, but mostly plant nutrients. Very helpful website below.