Human factors include pollution, deforestation, overpopulation, overexploitation, hybridization, and introduction of alien invasive species which all lead to habitat alteration or removal. The effect of altitude and slope in the species diversity. Although these pests are attacked by several species of parasitoids in major cerealgrowing regions zhou et al. Factors affecting woody plant species diversity of fragmented. Factors affecting species diversity of plant communities and the restoration process in the loess area of china. Factors affecting species richness of marine elasmobranchs. The results on the species diversity and species dominance are presented in table 3, which confirm that the status of forest biodiversity between the two strata is differing significantly. Ecological and historical factors affecting distribution pattern and richness of endemic plant species. Diagram depicting the effects of increased atmospheric carbon dioxide on global oceans.
The variation of species richness and diversity significantly correlated with time since abandonment, elevation and soil type. For example, the dominant factors affecting the appearance frequency of orchid and nonorchid species were altitude and the distance between population and road, respectively figure 2b, figure 2c. Environmental factors affecting understory diversity in. Factors affecting species diversity of plant communities and. Generally speaking, greater species diversity alpha diversity leads to greater ecosystem stability.
Factors affecting species diversitycorona species diversity 11. Factors affecting moorland plant communities and component species in relation to prescribed burning. Factors and processes affecting plant biodiversity in permanent. Learning objectives biodiversity define the meaning of the words species, niche and adaptation. Factors affecting woody plant species diversity of fragmented seasonally dry oak forests in the. These include the behavior, distribution, and ecology of the species. Because the coalition balances two different beliefs within society, and each party fight to get there view across to gain power, society is split into two seperate groups.
Environmental factors affecting the composition and diversity. How can species diversity affect ecosystem stability. Biodiversity factors affecting the variety of species in. Given the breadth of relevant human activities, the diversity of wildlife species potentially affected, and the multitude of ways they may be affected, scientists and resource managers planning to assess the effects of human activities on wildlife must be careful to state their study objectives explicitly. Environmental factors affecting endemic species, species richness and species diversity in saint catherine protectorate, south sinai, egypt. Understanding the factors that affect and are affected by small scale species richness is fundamental to community ecology. We used the software package modestr to determine the geographical distribution of all valid marine elasmobranch species 512 species of sharks and 619 species of batoids.
Abiotic factors anthropogenic and natural environmental variations are voraciously affecting the arthropods with the passage of time. Species richness s, and both shannonwiener and simpsons diversity indices were best explained by independent pca factors involving leaf litter, water volume, dissolved oxygen concentrations, and tank light levels. Pdf flora and factors affecting species diversity in the. The echinades islet group greece article pdf available in willdenowia 441. Pdf flora and factors affecting species diversity in. Flora and factors affecting species diversity in the islet groups of the protected natura 2000 sites of the amvrakikos gulf and mesolongi lagoon ionian area, greece. Multiple regression analysis showed significant positive correlation between under story diversity and tree seedling diversity and soil subgroup. Assessing the effects of human activities on wildlife. Biogeographic region components of species diversity. Population surveying and monitoring are important for identifying conservation needs and tracking trends in populations, communities, and ecosystems over time and laying the groundwork for conservation management and policy decisions. Nevertheless, the precise evaluation of biodiversity benefits remains challenging. It was noted that there is less tree species diversity in closed forest stratum compared to disturbed stratum. In this study, species diversity as a dependent variable, and topographic factors such as altitude and slope, as independent variables, or using oneway anova, were analyzed.
Factors affecting levels of genetic diversity in natural populations. First, it is known that certain metapopulation structures can result in effective population sizes. The general purpose of this study is to define the most important nonanthropogenic environmental variables affecting understory species diversity and distribution in second. Flora and factors affecting species diversity in protected natura 2000 sites of the ionian area. Factors affecting biodiversity in agrosylvopastoral ecosystems with in the mediterranean basin. May 10, 2017 many factors influence the alpha diversity found in a riverine ecosystem including the age of the river, dissolved oxygen, organic matter in the river, total suspended solids, pollution, introduction of invasive species, dams and changes to the river flow all affect biodiversity. Pdf environmental factors affecting endemic species. Factors influencing biodiversity and distributional gradients. Igune, a traditional agricultural landscape in the tohoku region of japan, is characterized by smallscale artificial woodlots surrounding a farmers house that are interspersed with paddy fields. Factors affecting stem borer parasitoid species diversity. In the first place, species diversity is surely not determined in all cases by the same single factor but is the outcome of many contributing factors.
Biodiversity is declining rapidly due to factors such as land use change, climate change, invasive species, overexploitation, and pollution. Cosmopolitan species pertinent or common to the whole world. In urban habitats, plant species diversity and composition have been explored to a considerable extent on variety of spatial scales, and therefore, factors affecting species richness and vegetation structure are well known pickett et al. Cosmopolitan distributions can be observed both in extinct and extant species. Factors influencing biodiversity and distributional. During the rapid economic growth of japan over recent decades, some igune woodlots have been abandoned or logged. W amos and j harwood school of environmental and evolutionary biology, university of st andrews, fife, uk. Fourteen environmental variables were measured for 46 sites. Environmental factors affecting the composition and. Biodiversity conservation is an important issue worldwide, and traditional. It is well known that variation in cli materainfall, temperature and range of temperaturestogether with some local factors such as slope, geologic substratum. Factors determining the plant species diversity and. Nevertheless, the precise evaluation of biodiversity benefits remains. It includes studies of the effects of introduced fish on native fauna, temporary stream insect diversity, and a study of community assembly in vernal pools.
Pdf factors affecting biodiversity in agrosylvopastoral. Feb 21, 2015 cosmopolitan species pertinent or common to the whole world. What are the factors that influence species diversity in a. Design and analysis of such experiments must account for several factors that covary with species diversity. Factors affecting species diversity of plant communities. Factors affecting media coverage of species rediscoveries. Factors affecting the distribution of animal and plant species by debbie and valeria temperature water temperatures affect the concentration of animals. Any other plants or animals are seen as pests and are killed, only. The same factors which limit species presence and growth, will also limit the functions and benefits of particular mangrove stands, such as shoreline stabilization, primary productivity, and habitat for a range of dependent organisms. Environmental effects on insects and their population dynamics. Factors affecting species diversity of plant communities and the restoration process in the loess area of china article pdf available in ecological engineering 363. Scribd is the worlds largest social reading and publishing site. Mar 22, 2011 research has delivered convincing findings on the effect of biodiversity on ecosystem functioning and humankind. My examples will be drawn mostly from the other papers of this sym posium.
Many factors influence the alpha diversity found in a riverine ecosystem including age of the river, dissolved oxygen, organic matter, total suspended solids, pollution, introduction of invasive species, dams and changes to the river flow all affect biodiversity generally speaking, greater heterogeneity leads to more niches available for exploration and more species exploiting those niches. Some of them are external or abiotic while others are internal or biotic coming from within the community. Factors affecting levels of genetic diversity in natural. Natural or humaninduced factors that directly or indirectly cause a change in biodiversity are referred to as drivers direct drivers that explicitly influence ecosystem processes. Many factors influence the alpha diversity found in a riverine ecosystem including age of the river, dissolved. Factors affecting species richness and distribution spatially. The factors affecting species and their habitats are often intertwined, and anthropogenic impacts may be exacerbated by naturally occurring processes. What factors affect diversity and species composition of. Biotic and abiotic factors affecting the biodiversity of. Speciation and evolution factors affecting evolution is the successive modification in inherited traits over a huge span of time, usually over generations.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Factors that influence species diversity in a habitat island include size of the island and its distance from the source population a larger island correlates to more nichesspace and more colonists and lower rates of extinction, closer to source pop means easier to migrate to island habitat higher rates of colonization, and lower rates. Natural factors affecting biodiversity include climate change, and natural disasters such as drought shah, 2011. The relative importance of factors affecting the diversity of aquatic macroinvertebrates differs among studies, suggesting there is considerable interhabitat and interclimatic varia tion. Species diversity is determined not only by the number of species within a biological communityi. In this study strong effect of florivory and folivory were significantly affected due to emission of hipvs contrary to the pollinator visitation 36. External temperatures affect all animals, especially those that do not maintain constant internal body temperatures. Human influences on tree diversity and composition of a. Biological factors that affect species richness competition competitive exclusion, perhaps the most often cited form of species interaction in ecology, occurs when one species species richness. A further major finding was that in the analysis of post. Biodiversity factors affecting the variety of species in an ecosystem unit 2.
For most of the endangered plants, the direct factors leading them susceptible to extinction are human activities 25, 36, 37. Research has delivered convincing findings on the effect of biodiversity on ecosystem functioning and humankind. Biogeographic region biogeographic region components of species diversity. Such natural or humaninduced factors referred to as drivers tend to interact and amplify each other. There are many factors which affect species richness. Factors affecting the distribution of animal and plant species. Other factors are involved purely spatial processes false correlations historical processes present distribution may not be in equilibrium with presentday climate the distributions and species diversity that we observe at the present day are a complex reflection of processes that operatehave. A species cannot outcompete another species due to their differences in competitive abil ities for different resources huston, 1979. The results showed that the altitude and slope, the diversity and species richness was significantly affected so that the slope of the lower classes less than 15%. Species abundance is the number of individuals per species, and relative abundance refers to the evenness of distribution of.
We used the software package modestr to determine the geographical distribution of all valid marine elasmobranch species 512 species of sharks and 619 species of. Exploring trends in species richness and the distribution of individual species over time as well as the factors affecting these trends informs conservation. This chapter identifies factors that could adversely affect key nearshore habitats and species, and possibly require management action. Time since abandonment is most important to the restoration process and species diversity is the main indicator of community changes in restoration in the loess plateau. Start studying factors affecting biodiversity biology. Species abundance is the number of individuals per species, and relative abundance. Pdf factors affecting species diversity of plant communities and. Several factors have been associated with biodiversity in fragmented landscapes. To account for species with large population sizes but low variability we advance three hypotheses. Factors affecting the distribution pattern of wild plants. Speciation is the evolutionary process by which new biological species arise. The regional species pool often contains higher species richness in a heterogeneous landscape, because of a higher diversity of suitable.
May 15, 2014 for example, the dominant factors affecting the appearance frequency of orchid and nonorchid species were altitude and the distance between population and road, respectively figure 2b, figure 2c. Many studies on elasmobranchs, sharks and batoids rays, skates and guitarfishes, have focused on the factors responsible for biomass decline, but little attention has been paid to the factors that affect species richness. The indoor biome is a novel habitat which recent studies have shown exhibit not only high microbial diversity, but also high arthropod diversity. Effects of environmental factors on the species richness. Cif disturbance is rare, the climax will be established and diversity reduced. Well email you at these times to remind you to study. If species or populations go undetected because of inadequate effort or sampling design, protection and management cannot be properly provided. Species richness and diversity did not differ with relative tank age, however abundances of a midge and a mosquito species did. Factors affecting macroinvertebrate richness and diversity. Indeed, ecosystems provide provisioning, regulating, supporting, and cultural services.
Factors affecting woody plant species diversity of fragmented seasonally dry oak forests in the mixteca alta, oaxaca, mexico. Ecological and historical factors affecting distribution. Biodiversity factors affecting the variety of species in an. The same factors which limit species presence and growth, will also limit the functions and benefits of particular mangrove stands, such as shoreline stabilization, primary productivity, and habitat for. The global phenomenon of rediscovering lost species. Three factors that affect the biodiversity in an ecosystem include area, diversity of niches, and climate. Diversity within society factors affecting diversity. Factors affecting the species richness, composition and horizontal.
The theory of evolution was first proposed by an english biologist named charles darwin. Factors affecting woody plant species diversity of. At the outset, let us be clear why the prob lem of understanding species diversity is com plicated. The diversitystability hypothesis states that ecosystems with greater species diversity are more stable.
Factors affecting species richness and distribution. Biotic and abiotic factors affecting the biodiversity of temporary waters in california. Political factors create diversity in one main way. Pdf the loess plateau of china is a special region that has suffered from soil erosion and water loss for a long time. Factors affecting biodiversity biology flashcards quizlet. Feb 28, 1998 factors affecting levels of genetic diversity in natural populations. The rediscovery of supposedly extinct species is a recurring global phenomenon driven by a complex interaction between biological and cultural factors ladle et al.
Factors affecting stem borer parasitoid species diversity and. This paper examines the changes in composition and diversity in plant community in the restoration of abandoned croplands to woodland, analyzes the effects of environmental factors on the restoration process and species diversity, and identifies the key factors for restoration in the loess area. What seven factors affect the biodiversity answers. Factors affecting moorland plant communities and component. Although climate change is relatively gradual compared to some factors affecting biodiversity, it is becoming more rapid and may be proceeding too swiftly for many native species to adapt.
Species richness and diversity increased, and evenness decreased in the restoration process. What factors influence the biodiversity of an ecosystem. Jun 15, 20 many studies on elasmobranchs, sharks and batoids rays, skates and guitarfishes, have focused on the factors responsible for biomass decline, but little attention has been paid to the factors that affect species richness. Factors and processes affecting plant biodiversity in.
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