The typical definition of biodiversity, also referred to as biological diversity, is the variability as well as a variety among living organisms, and the ecological complexes in which they take place (Coulston & Riitters, 2005). It may be considered in a hierarchical structure where degrees include species, genes, communities, populations, landscapes, and ecosystems. With no detailed information on actual diversity, there is a suggestion that protection of a community of plants may be a substitute for protection of the diversity of constituents linked to that community. Put differently, protecting a community of plants also offers protection to the species, genes, as well as populations inside that community. It is suggested that at least 12% of the land area in the world ought to be reserved so that to preserve biological diversity. Even though 12% might be enough to maintain biological diversity in a number of communities, other communities may need a smaller or greater percentage (Soulé & Sanjayan, 1998).
Since retaining biological diversity calls for protection all over a range of plant (Scott, et al., 2001), a better guide can be to establish protection thresholds on the basis of the plant community variation. If two communities of plants have a similar areal degree but one community has small variation while the other one has a big amount of variation, then the community that has the bigger amount of variation will need to reserve a bigger part of its geographic range to attain a similar degree of efficient protection.
Modern agriculture, medicine and industry all depend on a healthy level of biological diversity. Several medical cures are discovered via the probe of diseases in a broad array of organisms, and several nations, as well as cultures, depend on medicine obtained from plants. As for nutrition and agriculture, a range of local foods offers the nutritional value essential for a healthy diet. And even the majority of essential manufacturing materials are frequently obtained from a variety of living organisms. Additionally, adding value to day to day lives, a variety of organisms also contributes to the wellbeing of the environment. Biodiversity helps in natural processes for instance water purification as well as nutrient recycling.
Majority of threats to biological diversity can be ascribed to activities of human beings with the greatest being destruction and loss of habitat. One key cause of loss of habitat is deforestation, which if carried on at the current speed, will rub out all of the rain forests on earth in a century. Changes of land-use, as well as construction, are also important drivers of loss of habitat. Exploitation of resources and human pollution also add to loss of species. Excessive fishing, hunting, and usage of natural products all contribute to the reduction of biological diversity, as does the water and air pollution that many organisms need to live. This pollution includes unsuitable waste disposal, transportation and industry emissions, and application of pesticides and fertilizer. Change in climate and the introduction of encroaching species are also a threat to biological diversity. Change in climate affects loss of biological diversity by changing patterns of migration, acidification of oceans, and rising extreme events of weather, all of which might result in extinction of species.
Rapid loss of biological diversity is a universal phenomenon. It is approximated that probably half or more of all existing species could be at danger of extinction in the predictable future (Sax & Gaines, 2003). This loss of biological diversity is of vital concern, given that a rising amount of research shows that diversity has a significant role in long-term functioning of the ecosystem (Groombridge & Jenkins, 2002). Several aspects are adding to loss of biological diversity including modification of habitat, competition from species that have been introduced, human demand for some products and species, as well as fast changes in the environment, for instance, fluctuations of climate (Groombridge & Jenkins, 2002). Conserving large, intact regions of the natural environment is a fundamental way of conserving biological diversity. Nevertheless, this might not be practicable in highly urbanized areas where there is small natural habitat left. One feasible alternative is enhancing biological diversity in the ecosystem of urban areas. The loss of stands of natural forest and the degradation of the stands that are left, puts great significance on conserving as well as enhancing the biological diversity, which is available in forests in the urban areas.
Several processes and patterns cause a huge effect on urban biological diversity. In spite of proof that suburban and urban areas can hold comparatively high degrees of biological diversity, it is usually in agreement that the heavily settled urban center does not hold up almost as many species, particularly those that are indigenous as likened to less urbanized regions. A number of studies have demonstrated that the fragmentation and loss of the natural environment has decreased the richness of taxa, which include birds, plants, mammals, and insects in the urban center to less than 50% of the one found in rural areas (McKinney, 2002). Competition from exotic-invading species promotes reduction of native diversity of species. As one migrates from rural regions towards the city center, density of human population, density of road, pollution of soil and air, average temperature of air, compaction of soil, as well as alkalinity of soil have been demonstrated to rise (McKinney, 2002). As these modifications take place, there loss of the natural environment and is substituted with the managed vegetation, ruderal vegetation, as well as built environment.
A number of analyses depend on this approach of urban–rural gradient, in which biological diversity is examined along a transect from inside a city to nearby, less-changed ecosystems. Long-term management goals of biological diversity may be enforced more efficiently through the application of the apprehension of the urban–rural gradient. For instance, McKinney (2002) proposes that restoration of ruderal and managed habitats may be more practicable in the urban center as well as highly urbanized suburban area than developing remnant habitat. Nevertheless, the patterns and processes, which mold biological diversity in and around metropolises, require being more fully understood. The traditional inductions concerning the urban–rural gradient might not be well-grounded in every situation. Godefroid and Koedam(2003) examined the spatial disparity of assemblages of plants in a remnant forest, which is partly located in an administrative limits of a capital. As anticipated, forest stands, which were near to urban regions, held up more exotic and pioneer species than the interior of the forest. Surprisingly though, the stands were as well more expected to be settled by species that are classified as species of ancient forest as well as species that are rare. Up to 23% of species that are rare were seen in the edge of the forest, while fewer than 5% were seen in the interior of the forest. Such studies as this disclose that there may necessity to update the traditional presumptions concerning the urban–rural gradient as well as effects of forest edge (Godefroid & Koedam, 2003).
Promotion, as well as preservation of biological diversity in urban green-space, is among the ways to slow down the fast rate of loss of biological diversity. As the world turns increasingly urbanized, the forest in the urban will progressively become a significant reserve of biological diversity. There is need to acknowledge the possibility of urban regions to comprise of significant amounts of biological diversity, as well as work to enhance that diversity. In the future, there is the likelihood to see rising importance afforded to preservation, as well as promotion of biological diversity in the urban forest. Planners of cities, as well as foresters in the urban areas, will have the chance to enlarge the traditional functions through incorporation of a more ecological position into their management designs. Ecological, as well as social benefits will be acquired through protection of biological diversity, for instance raised tree health and greater aesthetical discernment. New alternatives of management ought to be examined and integrated into city plans that will ultimately result in more sustainable as well as biologically rich urban forests.
Coulston, J. W., & Riitters, K. H. (2005). Preserving biodiversity under current and future climates: a case study. Global Ecology and Biogeography, 14, 31–38.
Godefroid, S., & Koedam, N. (2003). Distribution pattern of the flora in a peri-urban forest: an effect of the city–forest ecotone. Landscape and Urban Planning, 65, 169–185.
Groombridge, B., & Jenkins, M. D. (2002). World Atlas of Biodiversity: Earth’s Living Resources in the 21st Century. Berkeley, CA: University of California Press.
McKinney, M. L. (2002). Urbanization, biodiversity, and conservation. BioScience, 52, 883–890.
Sax, D. F., & Gaines, S. D. (2003). Species diversity: from global decreases to local increases. Trends in Ecology and Evolution, 18, 561–566.
Scott, J. M., Davis, F. W., McGhie, R. G., Wright, R. G., Groves, C., & Estes, J. (2001). Nature reserves: do they capture the full range of America’s biological diversity? Ecological Applications, II, 999–1007.
Soulé, M. E., & Sanjayan, M. A. (1998). Conservation targets do they help? Science, 279, 2020–2061.