Endemic Species

7 Key excerpts on "Endemic Species"

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  Plant and Animal Endemism in California

  • Susan Harrison(Author)
  • 2013(Publication Date)
  • University of California Press

    (Publisher)

  However, in the literature on the biology of rarity, the term is sometimes used in a narrower sense. For example, in a classic review of endemism in higher plants, Kruckeberg and Rabinowitz (1985) define endemics as species existing as only one or a few populations. They note that such species can nearly always be considered rare in the sense of having very small geographic ranges. Many endemics (as defined by these authors) are also rare in the sense of having narrow niches; the best-known examples are plants specialized on particular soils, often called “edaphic endemics.” Ende-mism is uncorrelated with a third type of rarity, namely, low population density; these authors note that endemics are often locally abundant within their narrow geographic ranges or habitats. Appropriate Spatial Units Islands are natural units for defining and measuring endemism, because the boundaries of an island are clearly defined and obviously linked to the evolutionary processes giving rise to unique species. This is less true for almost any other kind of geographic unit. Political boundaries seem especially inappropriate since they are unrelated to biology, yet the Biotic Uniqueness: An Overview | 9 majority of the world’s biodiversity data are compiled by country, state, province, or other similar unit. In the United States, an important source of data is the Natural Heritage Network, a national program founded by the Nature Conservancy in the mid-1970s and now implemented by each state. Each member of the network—in California’s case, its Department of Fish and Wildlife—compiles occurrence records of imper-iled species and other conservation elements such as natural communi-ties and makes these records available in an interchangeable format. Analyses of these data (Stein et al. 2000), discussed in Chapters 3 and 4, point to California as the U.S.

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  Current Progress in Biological Research

  • Marina Silva-Opps(Author)
  • 2013(Publication Date)
  • IntechOpen

    (Publisher)

  2.1. Defining the term The idea of endemism dates back to more than 200 years, and has been employed, as it is actually understood, by de Candolle [1]). Since then, the concepts of endemicity and areas of endemism have been widely discussed. Some problems around these concepts emerge from the diverse uses and interpretations given to them in literature (e.g. [16, 20-21], Harold and Moii [21], Although differences between diverse uses as regards connotations could seem minor, the lack of precision in the definition of these concepts hinders an unambiguous interpretation and causes confusion. Additionally, numerous expressions, such as “general‐ ized track”, “track”, “biotic element”, “centers of endemicity”, “units of co-ocurrence”, among others, are commonly used as synonyms of area of endemism, [16, 21-23]. Although basically related with the term ”areas of endemism”, these concepts refer to different patterns of distribution and are defined on different theoretical grounds. 3. A clear conceptual framework As it usually happens in other fields such as morphology and embryology, in the field of biogeography, the identification and description of patterns precede the inference of the causes of its occurrence. However, some biogeographers assume that vicariance must be involved [12, 17]). According to this idea, a pattern of sympatry among species could be defined as area of Current Progress in Biological Research 4 endemism only if it emerged from a vicariant event. This assumption entails new difficulties for the identification of areas of endemism: the causes which originate the patterns must be known a priori, or else, the identification of patterns and processes should be performed simultaneously. Fortunately, most biogeographers follow the generalized concept, which supposes that multiple factors affect and define current patterns.

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  Protecting Life on Earth

  An Introduction to the Science of Conservation

  • Michael Paul Marchetti, Peter B. Moyle(Authors)
  • 2010(Publication Date)
  • University of California Press

    (Publisher)

  103 Biodiversity and Extinction 7 Conservation science depends a great deal on understanding the nature of biodiversity as well as on understanding the process of extinction. Biodiversity (aka biological diversity), as we will see below, has many facets and encompasses a wide range of ideas. Understanding some of these complexities will allow us to build bridges between ecological and evolutionary science and conservation science (aka conservation biology). In order to do this, we will first define what we mean by biodiversity, and then explore how it can be measured, examine where biodiversity is found, enumerate how many species we are dealing with, and discuss major threats to bio-diversity. In order to understand extinction, we will first describe what it means for a species to be extinct, and then look at what scientists know about the process of extinction from studying the fossil record. We will end the chapter with a discussion of the ongoing extinction event. BIODIVERSITY Biodiversity has been defined in many ways over the years, but we like the 1989 definition used by the World Wildlife Fund, which defines biodiversity as “the wealth of life on earth (all plants, animals, and microorganisms), the genes they contain, and the intricate ecosystems they help build.” This is a useful definition for many reasons, one of which is that it is inclusive and really captures the essence of what scientists mean by the term. In addition, it highlights that there are three distinct levels of biodiversity that are important for us to consider. First is the level of the species. Species biodiversity essentially considers the wealth of different species on the planet or at some more local geographic level. Species biodiversity includes the obvious organ-isms such as mammals and birds and trees but also encompasses all other forms of life such as mosses, bacteria, viruses, algae, worms, fungi, and microbes.

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  The Endangered Species Act at Thirty: Vol. 2

  Conserving Biodiversity in Human-Dominated Landscapes

  • J. Michael Scott, Dale D. Goble, Frank W. Davis, J. Michael Scott, Dale D. Goble, Frank W. Davis(Authors)
  • 2013(Publication Date)
  • Island Press

    (Publisher)

  The lesson from biotas past is far from an isolated and banal, academic exercise. In this particular case, if we are to preserve the natural character of North America’s sole surviving antelope—its size, great speed and endurance, and complex social system—we may need to maintain a diversity of its populations across its historic range and within ecosystems that continue to challenge it to survive by vigilance and speed (see Dudley 1999 for a similar case study for rare plants and now-vanished herbivores; see also Burney et al. 2001).

  Significance of Conservation Biogeography

  Preservation of native biotas in their natural state as integral components of functioning ecosystems and as significant and adaptable evolutionary units means that we should strive to preserve the geographic context of endangered biotas. This is not just a purist’s vision. Conservation of imperiled species requires that they maintain the speed, size, reproductive, predatory and avoidance behaviors, immune responses, and the many other survival strategies that in the past were maintained as responses to natural selection regimes across the species’ historic range. This, of course, requires a better understanding of the geographic structure of native species and their communities. The task, however, is plagued by an insidious catch-22 of conservation biology: we need to know the most about the rarest species—those that are likely atypical and difficult to study. We can develop sound inferences not just from the few snapshots and glimpses we have in recent time and limited locations but also from the wealth of studies on the history and prehistory of these and related species. How were they distributed in the past? How did their distributions change with climatic conditions, habitat shifts, or invasions by other species, including humans? Based on phylogenetic and phylogeographic reconstructions, we can determine the distinctiveness of focal species along with when, where, and in what forms their relatives persisted and perished (Avise 2000; Lockwood et al. 2002).

  David Steadman, Timothy Flannery, Paul Martin, and other distinguished scientists have chronicled the ecological history and biotic upheavals of the late Pleistocene and early Holocene (e.g., see Martin 1984; Flannery 1995, 2001; Steadman 1995; Steadman and Martin 1984). Their work has convinced many that few regions exist where ecological and evolutionary conditions are similar to those that produced any extant species. We do not have to dig too deeply into the fossil record to reconstruct these ghosts of communities and ecosystems past. The remains of native rodents of the Galapagos Islands, hundreds of species of Pacific island birds, and many thousands of other species of animals and plants from around the world have been collected just a few centimeters below the surface. These have provided us with a more complete picture of the natural, intact ecosystems as well as clues to the origins, persistence, and extinction of native biotas.

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  Conservation of Biodiversity and Natural Resources

  • Singh, M P, Soma Dey(Authors)
  • 2021(Publication Date)
  • Daya Publishing House

    (Publisher)

  Such species are usually localized within restricted geographical pockets or habitats or are thinly scattered over a more extensive range. Rare species have a population of less than 20,000 individuals. Some species are naturally rare and have never occurred in greater numbers, yet they are able to maintain these numbers. Other species become rare through man’s action or other unnatural forces. Extinct : Species that are no longer known to exist in the wild but survive under captivity or cultivation. Generally, the term Extinct is used for the species that are no longer known to exist in the wild. e.g. the Cheetah and Lesser Indian Rhinoceros. Threatened : It is a broader term that is used for species that fall into any of the vulnerable, rare and endangered categories. Threatened Animals Though the IUCN in 1988 listed 23 species of mammals as endangered or vulnerable to extinction, 75 species are totally protected as listed under schedule I of the Wildlife (Protection) Act 1972. Forests of the Western Ghat is famous for their endemic fauna and flora. The lion-tailed macaques, the Nilgiri Langur, the Malabar large-spotted civet, the Nilgiri tahr, etc. are some important endangered species. The Hoolock gibbon is the only ape found in the hilly forests of north-eastern India. Among the 19 primate species, 12 are endangered. The Manipur brown-antlered deer (Thamin), once distributed in some parts of the northeast, is perhaps the most threatened species. There are some 50 to 100 of them in the Keibul Lamjao on the bank of Logtak Lake sanctuary of Manipur. About 427 endangered plant species have been listed by the BSI for the red data book. This contributes about 20 per cent of the flouristic composition This ebook is exclusively for this university only. Cannot be resold/distributed. of higher plants of India. Some examples are given below. Eastern Himalaya Acer laevigatum, A. molle, Anglics anubigena, Bunium nothum, Carum villosum.

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  The Dry Forests and Woodlands of Africa

  Managing for Products and Services

  • Emmanuel N. Chidumayo, Davison J. Gumbo, Emmanuel N. Chidumayo, Davison J. Gumbo(Authors)
  • 2010(Publication Date)
  • Routledge

    (Publisher)

  Species richness (total number of species in a given area) and endemism (proportion of species restricted to a particular area) are often used to describe biodiversity. Endemic taxa are species or genera or families that have at least 75 per cent of their geographical range within one ecoregion. An ecoregion is characterized by a suite of plant taxa that respond to distinct patterns of landform, geology, soils and climate. Centers of endemism are areas of high concentrations of taxa that are endemic to an ecoregion. Because of taxonomic revisions, variable sampling effort and differences in delineating phytoregions, there are often large differences in estimates of species richness and levels of endemism among different workers. This problem is particularly acute in the case of dry forests and woodlands of Africa that are diverse and their delineations vary considerably among workers.

  Floristic diversity in African dry forests and woodlands was assessed by White (1983) and has recently been re-evaluated by Linder et al (2005) (Table 3.2 ). Both the assessments by White (1983) and Linder et al (2005) indicate that the Zambezian Regional Centre of Endemism has the highest floristic diversity of dry forests and woodland types. Mittermeier et al (2003) focusing on the Zambezian woodlands also identified the miombo-mopane woodlands as one of the five ecozones (together with Amazonia, Congo, New Guinea and the North American deserts) needing to be prioritized for biodiversity conservation because of their irreplaceability in terms of species endemism. The Zambezian Regional Centre of Endemism has eight endemic genera compared to four in the Sudanian Regional Centre of Endemism; however, endemic genera in the Somali-Masai Regional Centre of Endemism are even higher at 50 (White, 1983). The Zambezian phytoregion is also a centre of diversity for the Brachystegia and Monotes

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  Biodiversity in Horticultural Crops Vol. 6

  • Peter, K V(Authors)
  • 2018(Publication Date)
  • Daya Publishing House

    (Publisher)

  Chapter 2: Assessment on Endemism and Biodiversity among 34 Hotspots of the World Aparna Banerjee and Rajib Bandopadhyay* UGC-Centre of Advanced Study, Department of Botany, The University of Burdwan, Golabag, Burdwan – 713 104, West Bengal *E-mail: [email protected] Global scenario of biodiversity is changing as the sensitive factors; such as-land use, vegetation, climate, atmospheric green house gas concentration etc. are changing fast (Sala, 2000). The biodiversity is considered by diversity of life on Earth, and is calculated at different levels of biological set up together with genes, species and ecosystems along with its interactions. In 1992, Rio de Janeiro world summit, importance of biodiversity was the core point, which resulted in the Convention on Biological Diversity (CBD). The aims of CBD were ‘conservation of biological diversity, sustainable use of its components, and fair and equitable sharing of the benefits from the use of genetic resources’. But anthropogenic impacts resulted in gigantic biodiversity loss, including ecosystem disturbance, global warming, sea-level increase, habitat destruction, and loss of species genetic diversity. Now a days, species are heading towards extinction at the highest rate from the time when the mass extinction of dinosaurs (Banerjee, 2016). Biodiversity Hotspots A ‘biodiversity hotspot’ is a biogeographic stretch which should be both an important pool of biodiversity and also in danger of extinction. Species richness, endemism and threat to extinction- are the 3 factors that usually determine a hotspot. A biodiversity hotspot should accomplish two important This ebook is exclusively for this university only. Cannot be resold/distributed. criteria: it must include at least 1500 endemic vascular plants and also have 30 per cent or less of its natural fora, i.e.

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