We define the notion of evenness and show how the Lorenz curve can be used to compare evenness between abundance vectors. It is then illustrated how the Gini evenness measure can be used as a descriptive parameter in faculty evaluation studies.

Abstract Aim Biodiversity loss results in reduced ecosystem functioning. However, the relationship between biodiversity and functioning (the BEF relationship) overexploited ecosystems remains controversial largely because of lack validation nature. Therefore, this study, through four seasonal trawl surveys demersal fish assemblages off shelf sea Shandong Province, China, we explored relationshi...

The diversity and community structure of arthropods in an organic double-cropped rice ecosystem in Guangdong Province, China was studied. We compared the arthropod communities in the early season (Apr-Jul) crop to those in the late season (Aug-Nov) crop in 2009. The comparisons were undertaken using a combination of community assessment approaches, including morphospecies richness, the Shannon-...

Although measures of evenness of archaeological faunas are increasingly used in zooarchaeological analyses, the widely accepted hypothesis that increasing evenness should indicate increasing dietary breadth has not been tested. In this paper, I examine three factors that can contribute to changing evenness values—changing encounter rates with high-ranked prey types, changing diet breadth, and s...

To restore diversity of native vegetation, we must understand factors responsible for diversity in targeted communities. These factors operate at different spatial scales and may affect the number and relative abundances of species differently. We measured diversity of plant species and functional groups of species in replicated plots within paired restored and remnant (relic) tallgrass prairie...

Mating multiply may incur costs, such as exposure to predators and to sexually transmitted diseases. Nevertheless, it may be favored, in spite of these costs, as a way to increase the genetic diversity of offspring through fertilization by multiple males. Here, we tested for multiple paternity in a freshwater snail (Potamopyrgus antipodarum), which is host to several species of sterilizing trem...

Human activities are significantly altering nutrient regimes and the abundance of consumers in coastal ecosystems. A field experiment in an open-coast, upwelling ecosystem showed that small increases in nutrients increased the biomass and evenness of tide pool macrophytes where consumer abundance and nutrient loading rates were low. Consumers, when abundant, had negative effects on the diversit...

This study compared the parasite communities of Hoplias malabaricus and Hoplerythrinus unitaeniatus from Amazon river system. Hoplias malabaricus were infected by Ichthyophthirius multifiliis, Piscinoodinium pillulare, Tetrahymena sp., Urocleidoides eremitus, Braga patagonica, metacercariae of Clinostomum marginatum, Procamallanus (Spirocamallanus) inopinatus, larvae of Contracaecum sp. and lar...

The diversity and richness of species are of important components to evaluate the health of ecologic system of rangelands. This research was conducted to investigate the biodiversity in riparian and neighboring areas via comparison of indices in Javaherdeh rangeland of Ramsar. Plot-transects was randomly used to estimate diversity, richness, dominance, and evenness indices in two regions. Multi...