Island Species Richness Increases with Habitat Diversity

2009 ◽  
Vol 174 (6) ◽  
pp. E205-E217 ◽  
Author(s):  
Joaquín Hortal ◽  
Kostas A. Triantis ◽  
Shai Meiri ◽  
Elisa Thébault ◽  
Spyros Sfenthourakis
Keyword(s):  
Species Richness ◽  
Habitat Diversity ◽  
Island Species

scholarly journals Evaluating the correlation between area, environmental heterogeneity, and species richness using terrestrial isopods (Oniscidea) from the Pontine Islands (West Mediterranean)

2021 ◽  
Author(s):  
Gabriele Gentile ◽  
Roberto Argano ◽  
Stefano Taiti
Keyword(s):  
Species Richness ◽  
Environmental Heterogeneity ◽  
Geographic Distance ◽  
Habitat Diversity ◽  
Tyrrhenian Sea ◽  
Island Species ◽  
Random Placement ◽  
Species Area ◽  
Pontine Islands ◽  
Volcanic Islands

AbstractArea and environmental heterogeneity influence species richness in islands. Whether area or environmental heterogeneity is more relevant in determining species richness is a central issue in island biogeography. Several models have been proposed, addressing the issue, and they can be reconducted to three main hypotheses developed to explain the species-area relationship: (1) the area-per se hypothesis (known also as the extinction-colonisation equilibrium), (2) the random placement (passive sampling), and the (3) environmental heterogeneity (habitat diversity). In this paper, considering also the possible influence of geographic distance on island species richness, we explore the correlation between area, environmental heterogeneity, and species richness by using faunistic data of Oniscidea inhabiting the Pontine Islands, a group of five small volcanic islands and several islets in the Tyrrhenian Sea, located about 60 km from the Italian mainland. We found that the colonisation of large Pontine Islands may occur via processes independent of geographic distance which could instead be an important factor at a much smaller scale. Such processes may be driven by a combination of anthropogenic influences and natural events. Even in very small-size island systems, environmental heterogeneity mostly contributes to species richness. Environmental heterogeneity could influence the taxocenosis structure and, ultimately, the number of species of Oniscidea via direct and indirect effects, these last mediated by area which may or may not have a direct effect on species richness.

Diversity and distribution of large branchiopods in Kiskunság (Hungary) in relation to local habitat and spatial factors: implications for their conservation

2008 ◽  
Vol 59 (10) ◽  
pp. 940 ◽  
Author(s):  
Liesbet Boven ◽  
Bram Vanschoenwinkel ◽  
Els R. De Roeck ◽  
Ann Hulsmans ◽  
Luc Brendonck
Keyword(s):  
Species Richness ◽  
Hot Spot ◽  
Local Environment ◽  
Common Species ◽  
Habitat Diversity ◽  
Ecological Knowledge ◽  
Species Dispersal ◽  
Local Conditions ◽  
Spatial Factors ◽  
Large Branchiopods

Large branchiopods are threatened worldwide by the loss and degradation of their temporary aquatic habitats owing to drainage and intensive agriculture. Sound ecological knowledge of their diversity and distribution is a prerequisite to formulate effective conservation measures. In the present study, large branchiopods were collected from 82 temporary freshwater pools belonging to five habitat types in Kiskunság (Hungary). Dormant propagule bank analysis complemented the field survey. Eleven species were found, with large branchiopods occurring in more than half of the study systems. The high regional species richness and occurrence frequency of large branchiopods make Kiskunság a true ‘hot spot’ of large branchiopod diversity. The local environment was more important than spatial factors (isolation) in explaining the presence of the most common species. Dispersal was most likely not limiting for the large branchiopods in the study area and colonisation success of different species was differentially affected by local conditions, possibly invertebrate predation risk and hydroperiod. Meadow pools and wheel tracks contributed most to regional species richness through the presence of rare and exclusive species. To conserve branchiopod diversity, we stress the importance of high habitat diversity in the landscape and the need to conserve neglected habitats such as wheel tracks.

scholarly journals A global model of island species–area relationships

2019 ◽  
Vol 116 (25) ◽  
pp. 12337-12342 ◽  
Author(s):  
Thomas J. Matthews ◽  
François Rigal ◽  
Kostas A. Triantis ◽  
Robert J. Whittaker
Keyword(s):  
Species Richness ◽  
Structural Equation ◽  
Negative Relationship ◽  
Equation Model ◽  
Local Scale ◽  
Ecological Process ◽  
Global Pattern ◽  
Island Species ◽  
Species Area ◽  
Globally Distributed

The increase in species richness with island area (ISAR) is a well-established global pattern, commonly described by the power model, the parameters of which are hypothesized to vary with system isolation and to be indicative of ecological process regimes. We tested a structural equation model of ISAR parameter variation as a function of taxon, isolation, and archipelago configuration, using a globally distributed dataset of 151 ISARs encompassing a range of taxa and archipelago types. The resulting models revealed a negative relationship between ISAR intercept and slope as a function of archipelago species richness, in turn shaped by taxon differences and by the amount and disposition of archipelago area. These results suggest that local-scale (intra-archipelago) processes have a substantial role in determining ISAR form, obscuring the diversity patterns predicted by island theory as a function of archipelago isolation. These findings have implications for the use and interpretation of ISARs as a tool within biogeography, ecology, and conservation.

Organisation de la richesse et de la composition floristiques d'îles de la Méditerranée occidentale (sud-est de la France)

1998 ◽  
Vol 76 (2) ◽  
pp. 321-331 ◽  
Author(s):  
Frédéric Médail ◽  
Éric Vidal
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Species ◽  
Habitat Diversity ◽  
Mediterranean Islands ◽  
Plant Dispersal ◽  
Number Of Species ◽  
Continental Islands ◽  
Species Area ◽  
Species Area Relationship

The effects of physiographic variables (area, isolation, elevation, and substrate) and habitat diversity on plant species richness and composition have been investigated on some Mediterranean islands (southeastern France). The number of species - area relationship is significant but there are more diverse vegetation patterns on smallest islands (area smaller than 3.5 ha and, ultimately, 0.2 ha). Although the species composition is positively correlated to the distance from the continent, the effect of isolation is not so obvious because of the small distance of these continental islands from the continent. Some islands nearest to shore show very different plant species composition, suggesting a nonselective plant dispersal through some narrow stretches of sea. Habitat diversity represents one of the major explanatory factors of the species richness; nevertheless, it is not possible to settle between the two hypotheses effect of habitat diversity versus effect of area per se because of the correlation between the two factors. Key words: Mediterranean islands, insular biogeography, number of species - area relationship, isolation, habitat diversity, islets.

scholarly journals Maintenance of biodiversity on islands

2016 ◽  
Vol 283 (1829) ◽  
pp. 20160102 ◽  
Author(s):  
Ryan A. Chisholm ◽  
Tak Fung ◽  
Deepthi Chimalakonda ◽  
James P. O'Dwyer
Keyword(s):  
Species Richness ◽  
Island Biogeography ◽  
Mechanistic Model ◽  
Neutral Theory ◽  
Small Island ◽  
Small Islands ◽  
Island Area ◽  
Island Species ◽  
Theory Of Island Biogeography ◽  
Species Area

MacArthur and Wilson's theory of island biogeography predicts that island species richness should increase with island area. This prediction generally holds among large islands, but among small islands species richness often varies independently of island area, producing the so-called ‘small-island effect’ and an overall biphasic species–area relationship (SAR). Here, we develop a unified theory that explains the biphasic island SAR. Our theory's key postulate is that as island area increases, the total number of immigrants increases faster than niche diversity. A parsimonious mechanistic model approximating these processes reproduces a biphasic SAR and provides excellent fits to 100 archipelago datasets. In the light of our theory, the biphasic island SAR can be interpreted as arising from a transition from a niche-structured regime on small islands to a colonization–extinction balance regime on large islands. The first regime is characteristic of classic deterministic niche theories; the second regime is characteristic of stochastic theories including the theory of island biogeography and neutral theory. The data furthermore confirm our theory's key prediction that the transition between the two SAR regimes should occur at smaller areas, where immigration is stronger (i.e. for taxa that are better dispersers and for archipelagos that are less isolated).

scholarly journals Biogeography of Mammals in Rocky Mountain National Parks

1991 ◽  
Vol 15 ◽  
pp. 25-28
Author(s):  
Susan Glenn ◽  
Brian Chapman ◽  
Rebecca Rudman ◽  
Ian Butler
Keyword(s):  
Species Richness ◽  
National Parks ◽  
Rocky Mountain ◽  
Effective Area ◽  
Habitat Diversity ◽  
Initial Population ◽  
Mammal Species ◽  
Number Of Species ◽  
Local Extinctions ◽  
Equilibrium Number

The equilibrium theory of island biogeography proposes that on an island of a given area, there exists an equilibrium number of species when the rates of immigration and local extinction of species are equal (MacArthur and Wilson 1967). This theory has been applied to park systems because parks may act as functional islands when surrounding unprotected land is cleared of natural vegetation. Alteration of these surrounding habitats isolates these parks and reduces the effective area, causing a decrease in the equilibrium number of species. In animal communities, this process is called faunal collapse (Soule et al. 1979).The effects of park isolation and faunal collapse have been studied for mammals in Rocky Mountain parks (Picton 1979, Newmark 1986, Glenn and Nudds 1989). In western U.S. parks, extinctions were more numerous in smaller or older parks (Newmark 1987). Area, topographic diversity, and habitat diversity have been correlated with mammal species richness in western North American parks (Picton 1979, Newmark 1986). Initial population size was also related to the extinction probability of a species (Newmark 1986). It has been proposed that all parks in a region are subject to similar factors influencing local extinctions, and therefore a similar suite of species should become locally extinct in all parks (Patterson and Atmar 1986, Patterson 1987). This means that a nested subset pattern is produced, where parks with low species richness contain mainly species already present in parks with high species richness. This pattern was not found for Canadian parks, where even small parks contained different species assemblages (Glenn 1990). The objectives of this three-year study are to: (i) identify mammal species that have become locally extinct in each of the Rocky Mountain National Parks; (ii) distinguish between hypotheses regarding the causes of these local extinctions in National Parks; (iii) determine if the same species become locally extinct in all parks; and (iv) identify potential sites for future protection of species prone to extinction.

scholarly journals Patch size does not always indicate bird species diversity: case in peri-urban tropical habitat in Riau, Indonesia

2021 ◽  
Vol 948 (1) ◽  
pp. 012028
Author(s):  
M K Alghifari ◽  
A Mardiastuti ◽  
Y A Mulyani
Keyword(s):  
Species Richness ◽  
Human Activities ◽  
Bird Species ◽  
Diversity Indices ◽  
Early Morning ◽  
Habitat Diversity ◽  
Urban Habitat ◽  
Large Patch ◽  
Small Patch ◽  
Point Counts

Abstract Larger patches generally are inhabited by higher species richness, including birds, as predicted by the island biogeography theory. The objective of this research was to reveal the response of bird species richness in different patch sizes in peri-urban habitat. The study site area was five patches (2 large patches near human activities, remote large patch with a small lake, small patch, corridor patch) of disturbed secondary shrub-forest in Riau University, Sumatra. Birds were observed using the standard point-counts in early morning and late afternoon (8 points/patch, 3 replicates, total 40 observation-hour) in March-April 2021. Species richness (S), Shannon-Wiener diversity indices (H’), Chao species prediction, and Bray-Curtis similarity indices (B) were calculated. Total of 979 individual birds were observed, consisted of 68 species from 28 families with B ranged from 0.573 to 0.846. Large patch with lake in remote area had the highest species richness (S:39 species, Chao:54) and H’ (3.097). However, two large patches closed to human activities had the lowest number of species (S:27, Chao:30, H’:2.908, and S:23, Chao:32, H’:2.938, respectively), even lower than small patch (S:30, Chao:40, H’:2.925) or corridor patch (S:34; Chao:51, H’:2.724). Clearly human disturbance and micro-habitat diversity affect species richness in a local scale.

scholarly journals The determinants of alpine butterfly richness and composition vary according to the ecological traits of species

2014 ◽  
Author(s):  
Vincent Sonnay ◽  
Loïc Pellissier ◽  
Jean-Nicolas Pradervand ◽  
Luigi Maiorano ◽  
Anne Dubuis ◽  
...  
Keyword(s):  
Species Richness ◽  
Essential Element ◽  
Diet Breadth ◽  
Habitat Diversity ◽  
Dispersal Ability ◽  
Global Changes ◽  
Butterfly Species ◽  
Environmental Predictors ◽  
Plant Richness ◽  
Main Determinants

Predicting spatial patterns of species diversity and composition using suitable environmental predictors is an essential element in conservation planning. Although species have distinct relationships to environmental conditions, some similarities may exist among species that share functional characteristics or traits. We investigated the relationship between species richness, composition and abiotic and biotic environment in different groups of butterflies that share ecological characteristics. We inventoried butterfly species richness in 192 sites and classified all inventoried species in three traits categories: the caterpillars diet breadth, the habitat requirements and the dispersal ability of the adults. We studied how environment, including influence butterfly species richness and composition within each trait category. Across four modelling approaches, the relative influence of environmental variables on butterfly species richness differed for specialists and generalists. Climatic variables were the main determinants of butterfly species richness and composition for generalists, whereas habitat diversity, and plant richness were also important for specialists. Prediction accuracy was lower for specialists than for generalists. Although climate variables represent the strongest drivers affecting butterfly species richness and composition for generalists, plant richness and habitat diversity are at least as important for specialist butterfly species. As specialist butterflies are among those species particularly threatened by global changes, devising accurate predictors to model specialist species richness is extremely important. However, our results indicate that this task will be challenging because more complex predictors are required.

scholarly journals From Forest Soil to the Canopy: Increased Habitat Diversity Does Not Increase Species Richness of Cercozoa and Oomycota in Tree Canopies

2020 ◽  
Vol 11 ◽  
Author(s):  
Robin-Tobias Jauss ◽  
Susanne Walden ◽  
Anna Maria Fiore-Donno ◽  
Kenneth Dumack ◽  
Stefan Schaffer ◽  
...  
Keyword(s):  
Species Richness ◽  
Beta Diversity ◽  
High Throughput Sequencing ◽  
Habitat Diversity ◽  
Specific Primers ◽  
Operational Taxonomic Units ◽  
Microbial Eukaryotes ◽  
Tree Canopies ◽  
Species Performance ◽  
Factor Governing

Tree canopies provide habitats for diverse and until now, still poorly characterized communities of microbial eukaryotes. One of the most general patterns in community ecology is the increase in species richness with increasing habitat diversity. Thus, environmental heterogeneity of tree canopies should be an important factor governing community structure and diversity in this subsystem of forest ecosystems. Nevertheless, it is unknown if similar patterns are reflected at the microbial scale within unicellular eukaryotes (protists). In this study, high-throughput sequencing of two prominent protistan taxa, Cercozoa (Rhizaria) and Oomycota (Stramenopiles), was performed. Group specific primers were used to comprehensively analyze their diversity in various microhabitats of a floodplain forest from the forest floor to the canopy region. Beta diversity indicated highly dissimilar protistan communities in the investigated microhabitats. However, the majority of operational taxonomic units (OTUs) was present in all samples, and therefore differences in beta diversity were mainly related to species performance (i.e., relative abundance). Accordingly, habitat diversity strongly favored distinct protistan taxa in terms of abundance, but due to their almost ubiquitous distribution the effect of species richness on community composition was negligible.

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