In virtually all ecological communities around the world, most species are represented by few individuals, and most individuals come from only a few of the most common species. Why this distribution of species abundances is so regularly observed among different taxonomic sets in geographically diverse systems is a question that has received considerable theoretical and empirical investigation (...

Patterns of tree abundance and dispersion in a tropical deciduous (dry) forest are summarized. The generalization that tropical trees have spaced adults did not hold. All species were either clumped or randomly dispersed, with rare species more clumped than common species. Breeding system was unrelated to species abundance or dispersion, but clumping was related to mode of seed dispersal. Juven...

The aim of this study was modelling the spatial distribution ofLilium ledebourii (Baker) Boiss. based on ecological characteristics, in order to predict potential habitats for conservation of a rare plant. Knowledge of the spatial distributions of rare and threatened species and the underlying ecological factors plays an important role in regional conservation assessments and development planni...

The exploitation of rare and endangered species can end in the species's extinction because the increased value people associate with rarity increases the economic incentive to exploit the last individuals, creating a positive feedback loop. This recently proposed concept, called the anthropogenic Allee effect (AAE), relies on the assumption that people do value rarity, but this remains to be e...

The Earth's evolutionary history is threatened by species loss in the current sixth mass extinction event in Earth's history. Such extinction events not only eliminate species but also their unique evolutionary histories. Here we review the expected loss of Earth's evolutionary history quantified by phylogenetic diversity (PD) and evolutionary distinctiveness (ED) at risk. Due to the general pa...

BACKGROUND It has recently been postulated that the value humans place on rarity could cause the extinction of rare species. This is because people are willing to pay the high costs of exploiting the last individuals. Many hobbies, such as ecotourism or the keeping of exotic pets may cause this effect--known as the anthropogenic Allee effect. However, the entire theory relies on the insofar und...

The study of planktonic foraminifera in Jorband section reveals two major events in Campanian- Maastrichtian boundary and early-late Maastrichtian bio-diversification. In this study, occurrence and species richness of planktonic foraminifera in Jorband area show the warm marine environment dominant during early to late Campanian and it could be correlating by tropical and subtropical biozones. ...