Species Richness, Species Rarity and Conservation Evaluation of Rich-Fen Vegetation in Lowland England and Wales

Why do areas with high numbers of small-range species occur where they do? We found that, for butterfly and plant species in Europe, and for bird species in the Western Hemisphere, such areas coincide with regions that have rare climates, and are higher and colder areas than surrounding regions. Species with small range sizes also tend to occur in climatically diverse regions, where species are likely to have been buffered from extinction in the past. We suggest that the centres of high small-range species richness we examined predominantly represent interglacial relict areas where cold-adapted species have been able to survive unusually warm periods in the last ca 10 000 years. We show that the rare climates that occur in current centres of species rarity will shrink disproportionately under future climate change, potentially leading to high vulnerability for many of the species they contain.

Download Full-text

Plant Communities of Rich-Fen Systems in England and Wales: I. Introduction. Tall Sedge and Reed Communities

Journal of Ecology ◽

10.2307/2259411 ◽

1980 ◽

Vol 68 (2) ◽

pp. 365 ◽

Cited By ~ 47

Author(s):

B. D. Wheeler

Keyword(s):

Plant Communities ◽

England And Wales ◽

Rich Fen

Download Full-text

SPATIAL VARIATIONS IN RARITY IN THE AEGEAN TENEBRIONID BEETLES (Coleoptera, Tenebrionidae)

Fragmenta Entomologica ◽

10.4081/fe.2006.8 ◽

2006 ◽

Vol 38 (2) ◽

pp. 227 ◽

Cited By ~ 2

Author(s):

S. Fattorini

Keyword(s):

Species Richness ◽

Population Density ◽

Spatial Patterns ◽

Rare Species ◽

Abundant Species ◽

Faunal Assemblages ◽

Aegean Islands ◽

Remote Islands ◽

Species Rarity ◽

Coleoptera Tenebrionidae

Three measures of species rarity were calculated to investigate possible spatial patterns of variation in tenebrionid community rarity on the Aegean islands. For each species rarity was evaluated as geographic distribution (mean incidence of species on islands in the archipelago), ecological tolerance (total area of the islands occupied) and population density (number of decades of species’ records from 1870 to 2000). In addition, Kattan’s index of vulnerability was computed. These rarity and vulnerability measures were used to construct analogous indexes at community level. Plotting species richness on island coordinates, produced a map where richness decreased in the centre of the archipelago, reaching highest values on peripheral islands. Geographic rarity increased from the centre of the archipelago to periphery. By contrast, ecological tolerance and population density show the following pattern: islands located very close to the Anatolian mainland, as well as those that are clumped, host the most eurytopic and abundant species, while remote southern islands have ecologically specialized faunas with low population density. Vulnerability (i.e. the reverse of Kattan’s index applied to communities) decreased in remote islands, which are usually also the smallest. As a whole the tenebrionid beetles on the Aegean Islands constitute threatened faunal assemblages of great ‘rarity’ under several dimensions, and some islands are especially rich in rare species, deserving special attention in conservation efforts.

Download Full-text

The role of rarity as a surrogate of marine fish species representation

PeerJ ◽

10.7717/peerj.8373 ◽

2020 ◽

Vol 8 ◽

pp. e8373

Author(s):

Fabio Albuquerque ◽

Yaiyr Astudillo-Scalia

Keyword(s):

Species Richness ◽

Marine Conservation ◽

Marine Biodiversity ◽

Fish Diversity ◽

Area Network ◽

Number Of Species ◽

Fish Biodiversity ◽

Presence Data ◽

Species Rarity ◽

A Site

Because the distribution of most of the species is poorly known, conservationists use surrogates to help maximize the representation level of all species. Historically, species richness has been used to calculate the importance of priority areas for conservation, but several studies revealed sites with high species richness often fail to determine the smallest number of sites that will protect the highest number of species. Rarity, however, has played a prominent role in safeguarding planning units. While the performance of rarity has been previously assessed in terrestrial systems, we tested the hypothesis that rarity of a site can be used as a measure of the importance of a site to a conservation network in marine ecosystems. We used the presence data (at a 1-degree resolution) to calculate five rarity indices of fish diversity at a global extent and compared the results to those obtained by using species richness and site complementarity. Our objectives were to: (1) determine if rarity indices can be used as surrogates of fish biodiversity by representing the highest number of species in the smallest number of sites; and (2) determine if the effectiveness of these indices to represent fish biodiversity is impacted by the metric used to define rarity. Results indicate that rarity could be an effective surrogate for marine fishes, as most results showed a mean of 100% effectiveness. In the context of marine biodiversity conservation, results show that rarity indices could be considered affordable and feasible surrogates of species representation, with the most significant benefit to those areas of the world that are in most need to access alternative tools. Results also open a new area of collaboration between biogeography and marine conservation biology since planners can use biogeographical patterns of rarity to enhance the performance of the current protected area network.

Download Full-text