Endemic Species
Endemic species are plants or animals that are native to a specific geographic area and are not naturally found anywhere else. These species have evolved and adapted to the unique environmental conditions of their habitat, making them particularly vulnerable to changes in their ecosystem. Conservation efforts often focus on protecting endemic species to preserve biodiversity and maintain the balance of their respective ecosystems.
5 Key excerpts on "Endemic Species"
eBook - ePub- Michael J. Jeffries(Author)
- 2006(Publication Date)
- Routledge(Publisher)
...The evolutionary concept defines a species by a single, distinct lineage with an identifiable evolutionary history and fate. Ecological diversity Taxonomic diversity classifies types of organisms and their relatedness but organisms do not live in isolation from one another or the physical world. Humans have long recognised different ecosystems of apparently interdependent life. Ecological science focuses on these patterns and processes, hence ecological diversity is the inclusive term for this third category. Ecological diversity covers a host of concepts; ecosystems, communities, assemblages, habitats, biomes and biogeographical regions. These are not one and the same, indeed some may not be biodiversity proper. The term ecosystem embraces the living organisms and non-living (abiotic) features such as climate and geology of a site. Some have argued that the inclusion of abiotic components excludes ecosystems from biodiversity. A community refers to organisms living together, essentially the live component of an ecosystem. Again this deceptively simple idea is problematic. The term implies a linkage, an interdependence of species that may not exist. Even tightly linked communities will harbour fleeting tourist species, moving through without necessarily playing any role whilst other communities may be very loosely tied assortments, often described as an assemblage. Habitat conjures up precise images such as the giant panda habitat, but the term may not mean anything if the species is not present; does giant panda habitat cease to exist should the giant panda become extinct? Biome is the term associated with global or continental scale, regional ecosystems defined by vegetation and fauna, in its turn largely determined by climate. A formation is a similar concept, relying solely on vegetation data...
eBook - ePub- Charles Krebs(Author)
- 2008(Publication Date)
- CSIRO PUBLISHING(Publisher)
...Species arise primarily by geographic isolation, and the patterns of isolation that have arisen from continental drift have resulted in some areas being much more species-rich than others. Many, but not all, of these areas of high biodiversity occur in the tropics. Identification of these hotspots of biodiversity has become important in recent years because humans have cleared more and more areas for agriculture and forestry, thereby endangering many species. Hotspots are defined in several different ways, but in general the measure used to define a hotspot is the number of Endemic Species that it contains. Endemic Species are those that occur in only one relatively small geographic area. The Hawaiian goose, for example, is an endemic bird found only on the islands of Hawaii and Maui. Figure 12.6 Species diversity of Alcid seabirds and of seals and sea lions (Pinnipedia) in relation to latitude. Southern latitudes are given as a minus sign. In neither of these marine groups is there a tropical to polar gradient in biodiversity. (Data from Proches 2001 ; drawing of horned puffin courtesy of Fairman Studios; photo of sea lions courtesy of Andrew Trites.) There are 34 hotspots of biodiversity around the globe (Figure 12.7). Hotspots are defined as areas containing at least 1500 endemic plant species. One surprising feature of this map is that not all the hotspots are in tropical countries. Many hotspots are tropical, but the Cape Floristic Province of South Africa and New Zealand are two examples of temperate hot spots. Polar regions contain no hotspots. Table 12.1 lists the size of the most important hotspots and the number of plant species and vertebrate species they contain. These data are incomplete and err in the direction of minimal species counts...
eBook - ePub- Richard John Huggett(Author)
- 2004(Publication Date)
- Routledge(Publisher)
...In other words, some species do not occupy all places that their ecological tolerances would allow. Often, a species has simply failed to reach the ‘missing bits’ by dispersing. To an extent, the actual range of a species is a dynamic, statistical phenomenon that is constrained by the environment: in an unchanging habitat, the geographical range of a species can shift owing to the changing balance between local extinction and local invasion. Moreover, it may enlarge or contract owing to historical factors, as so plainly shown by the spread of many introduced species and chance colonizers in new, but environmentally friendly, regions. SUMMARY Species are not uniformly distributed over the land surface. Fauna and flora display regional differences. The largest regions of animals and plants are biogeographical regions, each bearing a distinctive fauna and flora. Some families and even some orders of animals are endemic to particular biogeographical regions. Others families are shared by two or more regions. A few families are cosmopolitan, being found in all biogeographical regions. Biological evolution and geological evolution have acted together to produce the biogeographical regions, subregions, and the transition zones between them seen today. Species, genera, and families display three basic distributional patterns – large or small, widespread or restricted, and continuous or broken. Relict groups are remnants of erstwhile widespread groups that have suffered extinction over much of their former range, owing to climatic or evolutionary changes. Range size and shape display relatively consistent relationships with latitude and altitude. ESSAY QUESTIONS 1 Why do different regions carry distinct assemblages of animals and plants? 2 What conditions favour the survival of relict groups? 3 Why do species ranges tend to become bigger with increasing altitude and latitude? FURTHER READING Cox, C. B...
- Justin Garson, Anya Plutynski, Sahotra Sarkar, Justin Garson, Anya Plutynski, Sahotra Sarkar(Authors)
- 2016(Publication Date)
- Routledge(Publisher)
...Different kinds of rarity include abundance rarity (when there are few organisms of a species left), geographical or habitat rarity (endemics with limited or specific range), and temporal rarity (a biological event that only happens rarely). An area with rare or Endemic Species is more diverse than one without, other things being equal. The abundance rarity criterion is of course directly in conflict with the evenness criterion, since communities with more rare species will be by definition less even. Combined with the decision points presented above, this list of criteria suggests that all biological diversities cannot be fully captured by a single measure, although single measures and indices are often convenient and useful in practice. As noted, some of the criteria above trade off as a logical matter, for example, evenness and abundance rarity. But the problem is not just a conceptual one, as there is also empirical evidence that measures of diversity can be non-concordant. For example, Hughes et al. (2002) show that there is low concordance between species richness and endemic fish and coral species in Indo-Pacific coral reefs. Another example is provided by the data set from Neige’s (2003) study of the biogeography of Old World Sepiids or cuttlefish (Cephalopoda). Neige’s data show no simple relationship between cuttlefish species richness and his constructed measure of morphological disparity: richness does not predict disparity. I take the multiple conceptually and empirically incompatible ways of defining and operationalizing ‘‘biodiversity’’ given by the options above to establish a solid preliminary case for pluralism and at least shift the burden of proof to the anti-pluralist, for example, the eliminativist, an option canvassed below. Some of the possible ways of more carefully defining and operationalizing ‘‘biodiversity’’ given the plethora of options above will no doubt prove useless in some contexts...
eBook - ePubBiodiversity and Conservation
Characterization and Utilization of Plants, Microbes and Natural Resources for Sustainable Development and Ecosystem Management
- Jeyabalan Sangeetha, Devarajan Thangadurai, Goh Hong Ching, Saher Islam, Jeyabalan Sangeetha, Devarajan Thangadurai, Goh Hong Ching, Saher Islam(Authors)
- 2019(Publication Date)
- Apple Academic Press(Publisher)
...Although the way species are defined has different viewpoints that differ between groups and between taxonomists (Robson, 1928), but measurement of species richness and distribution are important tools in assessing the state of the environment as well as the direction and speed of change (MAR, 2005). 1.1.3 ECOSYSTEM DIVERSITY Chapin et al. (2002) and Diaz et al. (2006) defined ecosystem diversity as it describes the variety of different natural systems found in a region and is delimited and characterized by the variations in the plants and the animals found among biological communities and the physical landscapes that support them. According to Chakhaiyar (2010), there are different ecosystems on the planet, such as deserts, rainforests, and coral reefs are all part of Earth biologically diverse. The quantitative assessment of the diversity of the ecosystem, habitat or community levels remains problematic. The scientists (Whittaker, 1972; Chapin et al., 2002; Diaz et al., 2006; Chakhaiyar, 2010) suggested that it is possible to define what is in principle meant by genetic and species diversity, and to produce various measures. Therefore, there is no unique definition and classification of ecosystems at the global level (Chapin et al., 2002; Diaz et al., 2006). The interactions among the living organisms (animals, plants, and microbial resources) of the world with the physical environment to produce a wide variety of ecosystems may be described as a range of temporal and spatial scales. Three terms for measuring biodiversity over spatial scales: alpha (within-community diversity), beta (between-community diversity), and gamma (diversity of the habitats over the total landscape or geographical area diversity) is described by Whittaker (1972). 1.2 DISTRIBUTION OF BIODIVERSITY For nature and development, understanding the global distribution of biodiversity is one of the most significant objectives for ecologists (Benton, 2001)...
