Essay on Nitrogen Cycle
Understanding of biological process in the surrounding world and human body is of paramount importance for seeing the bigger picture of the world. Knowledge of biology makes us more conscientious and aware of ecological problems by showing the inherent connection between human beings and the environment. In addition, learning biology can help to understand the nature of life and develop one’s own perception of the origins of life.
Very interesting findings are presented in the article ‘Tropical Plants Go With The Flow ... Of Nitrogen.’ Researchers from the National Academy of Sciences (Benjamin Houlton of the Carnegie Institution's Department of Global Ecology, Lars Hedin and Daniel Sigman of Princeton University and Ted Schuur of the University of Florida) contested the theory that plants specialize in one specific source of nitrogen by showing that tropical plants, in fact, can derive this element from different sources.
Nitrogen is an important nutrient for plants, which means that they need to get it from the surrounding environment in order to live. Most plants can absorb nitrogen in three forms, namely nitrate (NO3-), ammonium (NH4+), or dissolved organic nitrogen (DON). Yet tropical plants are by far more flexible and can derive nitrogen from whichever source available. Benjamin Houlton, the leading researcher, makes a very interesting analogy between plants and children at pizza party: ‘they may prefer pepperoni, but if only plain cheese is available, they'll still have a slice.’
The research team analyzed the soil content of nitrate, ammonia, and dissolved organic nitrogen and measured each source's comparative role in the process of growth of different plant species. They discovered that in areas with little rainfall, nitrate was the main source of nitrogen, and in areas with much rainfall, ammonium was dominant. Plants were using the source of nitrogen which was abundant in the soil they grew on. There was enough dissolved organic nitrogen in both types of soil, yet plants didn’t rely primarily on it.
The scientists also used new measures and models of variations in the atomic masses of nitrogen compounds that are naturally present in plants and soils with a view to investigating the tropical plants' nutritional response to possible changes in environmental conditions. By examining these different masses, referred to as isotopic ratios, in drier and wetter climatic conditions, the researcher were amazed by the ability of whole forest ecosystems to undergo an abrupt shift in the nitrogen cycle and in the nutritional strategies.
As for the significance of the findings, the study gives hope that rainforests are able to survive the climate change trough adapting to different sources of nitrogen. When temperate plants suffer shifts in nitrogen availability, they are seriously endangered. Since they derive nitrogen from a single source, they are doomed to inhabit certain niches based on the availability of nitrogen. Lethal consequences are brought about by the crash of that single source.
This doesn’t apply to tropical plants, though. Therefore, the research offers hope that tropical plants will be able to survive climate change, which can prove devastating for other natural ecosystems.
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