Our environment is stressed out

Our environment is not to be taken lightly as is being done these days. No doubt, the biosphere is under stress, and it is vital that this 'stress' is analysed and removed. Why? Understand. The biosphere consists of all the life and ecosystems on Earth and the environments where they occur.  Ecological processes at the level of the biosphere include global climatic, oceanic, and atmospheric regimes, the planetary energy budget, and global nutrient cycles. These biospheric processes influence all life and ecosystems. At the same time, life and ecosystems also influence biosphere-level processes. Each species within a community exploits the environment and interacts with other species in a particular manner. Competition occurs when the biological demand for an ecological resource exceeds the supply, causing organisms to interfere with each other. Plants, for example, often compete for access to limited supplies of sunlight, water, nutrients, and space. Animals may compete for food, nesting sites, mates, and other resources. Intraspecific competition occurs when individuals of the same species vie for access to resources, while interspecific competition occurs between species. If a species is particularly effective at co-opting resources to its own benefit, it may displace other species, a phenomenon known as competitive displacement (or in extreme cases, competitive exclusion). This affects the presence and relative abundance of species in the community. Environmental stressors are factors whose influence is to constrain productivity, reproductive success, and ecosystem development. To some degree, stressors affect all organisms as well as their populations, communities, and ecoscapes (landscapes and seascapes). Stressors may be natural in origin like floods, droughts or wildfires, however, stressors associated with human activities are the most critical influence on species and ecosystems. In too many cases, anthropogenic stressors are causing important-and devastating- damage to resources that are needed to sustain people and their economy, and also to natural biodiversity and ecosystems. It is important to understand, however, that damage occurs when one or more stressors elicit responses that can be interpreted as a degradation of environmental quality. Such responses may include illness or death caused by an exposure of wild animals to pesticides, or as a reduction of the productivity of ecosystems, or the endangerment of vulnerable elements of biodiversity. Exposure to a higher intensity of environmental stressors can result in evolutionary changes if individual organisms vary in their tolerance and those differences are genetically based. At the community level, relatively vulnerable species will be reduced or eliminated from the habitat if the intensity of stress increases markedly. The niches of those species may then be occupied by more tolerant members of the community, or by invading species that are capable of exploiting a stressful but weakly competitive habitat. A prolonged intensification of stress will cause longer-term ecological change to occur. Consider, for example, a case in which a new powerhouse or a metal smelter is constructed in a forested landscape. If the smelter emits toxic sulphur dioxide gas, the toxic stress will damage the tree-sized plants of the forest and eventually cause them to give way to shrub-sized and herbaceous vegetation. If the long-term stress is extremely severe, the landscape could entirely lose its vegetation. This kind of damage has actually occurred around a number of Canadian smelters, such as those near Sudbury. Ecologists have described the general attributes of ecosystems that have been subjected to severe stress for a period of time. In general, as environmental stress intensifies significantly (such as by increasing pollution), the following changes are observed: mortality increases, especially of the most vulnerable species, species richness decreases, the stocks of nutrients and biomass become depleted, the rate of community respiration exceeds that of production, so the net production becomes negative, sensitive species are replaced by more-tolerant ones, top predators and large-bodied species may be lost from the ecosystem, previously self-maintaining ecosystems may require active management to sustain their desirable attributes, for example, to maintain declining populations of rare or economically valuable species that have become threatened. Ecosystems that are chronically exposed to intense stress (such as climate-stressed tundra) eventually stabilize. Typically, the stable ecosystems are low in species richness, simple in structure and function, and dominated by relatively small, long-lived species. As well, they have low rates of productivity, decomposition, and nutrient cycling. Hence, it is very important to study these stressors and the prediction of their effects on people, other species, and ecosystems with the aim of finding solutions. -Saumya Misra