Species diversity refers to the measure of diversity in an ecological community. Biodiversity acronyms areas countries marine terms definition biological diversity means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part. Species diversity is measured as the effective number of species, that is the number of equallyabundant species needed to obtain the mean proportional species abundance observed in the dataset of. Have you ever wondered how many species live on earth. Southeast asia currently has one of the highest rates of deforestation in the world, is home to multiple biodiversity hotspots, and the majority of its countries have developing economies with limited resources for biodiversity. The importance of species diversity and its components as criteria. Pdf measuring species diversity for conservation biology.
This conceptual diagram summarizes what we know about the shape of the biodiversityecosystem functioning bef relationship based on summaries of. The number of genes range from about in bacteria, up to 400 000 or more in many. It also takes into account evenness, which is the variation of abundance in individuals per species in a community. Diversity of the neglected and underutilized crop species. By not allowing one species or another to become overly dominant, a keystone. Accurately delimiting species and their geographic ranges is imperative for conservation, especially in areas experiencing rapid habitat loss. Genetic diversity is all the different genes contained in all individual plants, animals, fungi, and microorganisms. Woody species diversity and important value indices in.
Genetic diversity, which refers to genetic variation within and between populations, has a big role, too. Many of the plant species that are cultivated for food across the world are neglected and underutilized. Biologists estimate that species extinctions are currently 500 times the normal, or background, rate seen previously in earths history. Biodiversity refers to variation within the living world, while genetic diversity represents the heritable variation within and between populations of organisms, and in the context of this paper, among plant species. Numerous studies have shown that biodiversity is necessary for ecosystem function. Recent studies have shown that plant genetic diversity can be important for ecosystem functioning and in some cases its effects are comparable in magnitude to the effects of species diversity crutsinger et al. It is the number of different species of plants, animals, and microorganisms. There are two important descriptors of a community. Based on the calculation, it was found that the diversity index, species richness and evenness. Short paragraph on importance of ecosystem diversity. The economic value of biodiversity page 4 genetic diversity genetic diversity is the sum of genetic information contained in the genes of individuals of plants, animals and microorganisms. Evenness we can compare the actual diversity value to the maximum possible diversity by using a measure called evenness.
Species diversity refers to biodiversity at the most basic level and is the variety and abundance of different types of individuals of a species in a given area. For example, in the pacific northwest, salmon holds together the entire ecosystem. The evenness of the sample is obtained from the formula. Diversity at the species level, often combining aspects of species richness, their relative abundance, and their dissimilarity ma, 2005b. It occurs within a species as well as between species. Importance of biodiversity, challenges and strategies to. Grasslands are important culturally as outdoor science laboratories.
The current high rates will cause a precipitous decline in the biodiversity of the planet in. A recent estimate suggests that the eukaryote species for which science has names, about 1. Each species is the repository of an immense amount of genetic information. Loss of habitat diversity thus potentially leads to loss in species diversity the union of the species in all habitats, indicated by different symbols b. These plantings leave the population open to destruction from diseases and pests. We are going to think about general principles and the most obvious hypotheses. Three levels of biodiversity are commonly discussed genetic, species and ecosystem diversity.
Target species establishment could be improved by changing the order of introduction of species. Ecologists have found species diversity difficult to define and measure, and this may in fact reflect the possibility that it is a nonconcept hurlbert, 1971. Hidden species diversity in sylvirana nigrovittata. The relative importance of plant intraspecific diversity. The importance of tree species diversity the loss of the american elm from dutch elm disease brought to the forefront the danger of planting very few species, referred to as a monoculture.
In general, there have been two approaches to measuring species. Genetic diversity and conservation and utilization of. Pdf article animal species diversity driven by habitat. The relative importance of plant intraspecific diversity in. Finally, grasslands provide many ecosystem services to society, including nutrient capture, food production, carbon storage, tourism and recreation, and nectar and pollen production. For many decades, ecologists believed that communities with more species, generally, tend to be more stable. Species diversity is all the differences within and between populations. However, the great range of diversity indices and models, which go beyond species richness, is evidence of the importance of the relative abundance of species. Woody species diversity and important value indices in dense. The effects of fishing on species and genetic diversity.
Pdf the importance of species diversity and its components as. The methods on offer range from the familiar, such as the calculation of various diversity indices and the fitting of common distributions, to more recentlydeveloped techniques such as total species complement estimators. Fishing can also alter genetic diversity within populations, even when numbers are high. The current high rates will cause a precipitous decline in the biodiversity of the planet in the next century or two. Endemism has a key role to play in this context because endemic species are restricted to small areas and provide pockets of particularly high genetic diversity. Ecosystem stability impacts population growth and decay and because of the asymmetry between gain and loss in systems governed by power laws, volatility cost on the ecosystem goes beyond the direct local dependencies. Keystone species play an important role, both in maintaining species diversity and the health of an ecosystem. Cobbold 1school of mathematics and statistics, university of glasgow, uk 2boyd orr centre for population and ecosystem health, university of glasgow, uk abstract realistic measures of biodiversity should re. Our results suggest that plant genetic diversity has significant effects on the diversity of arthropods across several trophic levels, thus highlighting the importance of maintaining high levels of both plant species and genetic diversity for arthropod conservation. Patterns and processes at least 120 different overlapping hypotheses explaining species richness. The importance of niches for the maintenance of species.
Homogenized ecosystems will reduce the diversity of species and consequently diminish valuable ecosystem functions and services. In addition to affecting species diversity, reduced habitat diversity may also directly impair ecosystem functioning. The diversity index shanonwiener diversity index, 1949 species richness margalefs index, 1958 and evenness pielou, 1996, of moth fauna werethen calculated. We screened each publication for terms that were used to define habitat. Spatial patterns of species diversity in kenya wur edepot. Species diversity, stand structure, and species distribution. The main difference between species diversity and ecosystem diversity is that the species diversity is the variety of species in a particular region whereas the ecosystem diversity is the variety of ecosystems in a particular area species diversity and ecosystem diversity, along with genetic diversity, are the three levels of biodiversity on the earth. Genetic diversity, ecosystem diversity and species diversity. In general term the biodiversity or biological diversity ia variation of species of all type of natural habitats with presence of certain species. For example, think about bald eagles in north america. Habitat diversity and ecosystem multifunctionalitythe.
Genetic diversity and conservation and utilization of plant. Secondly, ecosystem diversity can refer to diversity within an ecosystem. Animal species diversity driven by habitat heterogeneity. An overview of plant biodiversity is provided in this chapter.
Species richness cannot serve as a criterion for the creation of protected areas and species diversity is poorly suited for this as well. Genetic diversity is the variation in the genetic composition of individuals in a population, community or species evolves as a result of many different processes. Species richness the simplest way to describe a community is to list the species in it. The proposed index incorporates an importance weight to each species of organisms found in an ecosystem. Genetic diversity provides the fundamental basis for evolution of forest tree species. The study revealed 41 neglected and underutilized crop species nucs among which 19 were.
C ountless species of plants, animals, and microbes fill every crack and crevice on land and in the sea. Birds, furthermore, play an informational role in attracting public attention to natural habitat. If you were to measure the species richness of a forest, you might find 20 bird species, 50 plant species. Collected moth species were identified up to familygenus species level. Ecosystem stability impacts population growth and decay and because of the asymmetry between gain and loss in systems go. Species diversity then is the number of different species coexisting within a community, for example bear, humans, birds and dogs. However, despite the importance of this information, few detailed data have been obtained for tropical forests 26. Species diversity and richness 4 is designed for professional ecologists and their students. To assess their diversity in benin and identify the priority species and establish their research needs, a survey was conducted in 50 villages distributed throughout the country. The importance of species diversity and its components as criteria for selecting nature conservation areas article pdf available in russian journal of marine biology 377. Diversity, species richness and evenness of arctiidae and.
The extent and distribution of genetic diversity in a plant species depends on its evolution and breeding system, ecological and geographical. In this lesson, you will learn about the importance. First, you must understand that biodiversity really just means the diversity of life in any given place and time. The relationship between species diversity and ecosystem. Changes in habitat diversity can affect ecosystem functioning not only directly through changes in structural complexity and the crosshabitat exchange of nutrients and other resources c. Species diversity takes into consideration species richness, which is the total number of different species in a community. What is species diversity and why is it important learn vocabulary, terms, and more with flashcards, games, and other study tools. In some places and some groups, hundreds of species exist, whereas in others, very few have evolved. Biogeographic region components of species diversity.
This is a question for which ecologists have not been able to give a definitive answer. Species diversity is defined as the number of species and abundance of each species that live in a particular location. It includes organisms from earths vastly different ecosystems, including deserts, rainforests, coral reefs, grasslands, tundra, and polar ice caps. Chapter 2 biodiversity, ecosystems and ecosystem services. Species abundance is the number of individuals per species, and relative abundance refers to the evenness of distribution of individuals among species in. The diversity index, species richness and evenness of moth fauna in peshawar were 3. Every natural and manmade ecosystem is made up of a variety of animal and plant species.
Many plant species are threatened by habitat transformation, overexploitation, invasive alien species. It is generally recognized that plant genetic diversity changes in time and space. Details of genetic diversity, species diversity and ecosystem diversity are given. Generally, a species is a group of similar individuals capable of interbreeding and producing offspring.
A keystone species is an organism that helps maintain species diversity within an ecosystem by keeping the numbers of other species in an ecosystem constant. Lepidoptera, diversity, pakistan, peshawar introduction diversity can be defined as the number of different items and their relative frequency. Biodiversity refers to the variety of living species on earth, including plants, animals, bacteria, and fungi. What is the difference between species diversity and. And so, while we dominate this planet, we still need to preserve the diversity in wildlife. Species richness and species frequencies alpha diver sity have long been. Third, the importance of stochastic processes due to priority effects has been supported by recent studies and have challenged the deterministic assembly model. Species diversity is determined not only by the number of species within a biological communityi. Some ecosystems such as tropical rainforests are very rich in the number of species as compared to other ecosystems such as the desert ecosystem. Certain species, such as herring have a large number of populations, while others such as mackerel have fewer.
Salmon carry rich nutrients from the ocean back to the stream. The living layer is being simplified, its area reduced, and species richness and diversity are declining 1, 2, 4, 6, 9, 16, 52, and many others. A new importancediversity index is proposed as an enhancement to the traditional shannons diversity index. Our biodiversity is very important to the wellbeing of our planet. It includes all the species on earth, ranging from plants such as bacteria, viruses, fungi, algae, bryophytes, pteridophytes, gymnosperms, angiosperms and all the species of. Apr 27, 2019 first, you must understand that biodiversity really just means the diversity of life in any given place and time. The importance of species diversity to the ecosystem. Among species, birds have an important place because they are visible and highly valued by humans. In that concern, this study was carried out in abdoulaye wildlife reserve awr with a specific objective to assess woody species diversity. Species diversity is an important component of the health of an ecosystem. Species diversity is measured in relation to a given area from a small field to the entire planet.
The convention on biological diversity plant conservation report. Any species vulnerable to endangerment in the near future. However, this is not to say that such measures are mutually exclusive. The majority of these, however, have taken place at relatively small experimental scales. At present the scientists have been able to identify 1.
That is what makes our country one of the 12 mega diversity countries of the world. Species turnover promotes the importance of bee diversity. In ecosystems where there are species to species direct and indirect dependencies, diversity loss impacts ecosystem stability. The importance of plant diversity and the need for its conservation incorporated into. Nov 09, 2018 biodiversity refers to the total number of the species plants and animals and variety of living beings. There are numerous reasons why species diversity is essential.
Functional diversity is a component of biodiversity that generally covers the range of functional traits of microorganisms prevailing in an ecosystem. Species diversity may affect ecosystem functions, such as the productivity of a. The importance of species diversity to the ecosystem sciencing. Ecosystems around the globe are facing habitat homogenization due to human activities. Biodiversity, ecosystems and ecosystem services 7 biodiversity at a suitable scale, e. Usually three levels of biodiversity are discussedgenetic, species, and ecosystem diversity. By not allowing one species or another to become overly dominant. When species are examined for biodiversity, three elements are looked at. The maximum diversity hmax of a sample is found when all species are equally abundant. Nearly 45,000 species of plants and twice as many of animals have been recorded from india. Incorporating social and ecological importance of species dexter salinas ontoy academia. Despite considerable effort, knowledge of the species that inhabit the planet is limited. Biodiversity is the amount of variety of life on earth.
Jan 19, 2014 greater species diversity ensures natural sustainability for all life forms healthy ecosystems can better withstand and recover from a variety of disasters. Why is ecological diversity biodiversity important. Diversity in ecosystem includes species diversity, habitat diversity and ecosystem diversity. They make the world go round, converting sunlight to energy that fuels the rest of life, cycling carbon and nitrogen between inorganic and organic forms, and modifying the landscape. For biological diversity, these items are organized at many levels. It can be assessed in terms of the number of species or the range of different types of species an area contains. The number of species that live in a certain location is called species richness.
Functional diversity is of high ecological importance because it is capable of influencing several aspects of ecosystem functioning like ecosystem dynamics, stability, nutrient availability, etc. Genetic diversity is all the different genes contained in all the living species, including individual plants, animals, fungi, and microorganisms. The other component of biodiversity, species evenness, is more informative. Biodiversity and conservation although india h as only 2. Biological diversity variation in genes, species, functional traits expand our focus improve predictions link functions to services figure 1 the form of a typical diversity function relationship. So, the gobi desert has its typical biodiversity that includes a very small number of species in comparison with something like the. Species diversity is all the different species, as well as the differences within and. A taxonomic category or group, such as phylum, order, family, genus or species. The convention on biological diversity plant conservation. The concepts of niche width and habitat diversity are of utmost importance for understanding ecosystem function. An ecosystem can only truly thrive if all life forms in it are thriving.
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