Use of extensive habitat inventories in biodiversity studies

Abstract

Large monitoring programs exist in many countries and are necessary to assess present and past biodiversity status and to evaluate the consequences of habitat degradation or destruction. Using such an extensive data set of the floristic richness in the Paris Ile-deFrance region (France), we compared different sampling efforts and protocols in different habitat units to highlight the best methods for assessing the actual plant biodiversity. Our results indicate that existing data can be used for a general understanding of site differences, but analysts should be aware of the limitations of the data due to non-random selection of sites, inconsistent observer knowledge, and inconsistent sampling period. The average species diversity recorded in a specific habitat does not necessarily reflect its actual diversity, unless the monitoring effort was very strong. Overall, increasing the sampling effort in a given region allows improvement of the (1) number of habitats visited, (2) the total sampled area for a given habitat type, (3) the number of seasons investigated. Our results indicate that the sampling effort should be planned with respect to these functional, spatial and temporal heterogeneities, and to the question examined. While the effort should be applied to as many habitats as possible for the purpose of capturing a large proportion of regional diversity, or comparing different regions, inventories should be conducted in different seasons for the purpose of comparing species richness in different habitats.

Habitat type richness associations with environmental variables: a case study in the Greek Natura 2000 aquatic ecosystems

“…Based on the notion that a well-established association among environmental parameters and ecological entities, could be projected to higher or lower organizational levels (Noss 1990;Naeem et al 1994) and considering the documented relationship of habitat type richness with species richness (e.g. Kallimanis et al 2008;Muratet et al 2009), the observed associations of habitat type richness with environmental parameters could be attributed to lower levels of ecological diversity, i.e. species richness.…”

“…species richness. In fact, in most cases it has been shown that habitat type richness in an area is positively correlated with the number of species in it (Triantis et al 2006;Kallimanis et al 2008;Muratet et al 2009). Apart from that, the ability to observe similar responses to the higher ecosystem level would be indicatory of the accuracy of our findings.…”

Local gardening practices shape urban lawn floristic communities

“…The list of all wild vascular plant taxa was established once in each quadrat during autumn 2007. This single-season sampling did not allow us to estimate the whole diversity present in urban lawns over a year or to evaluate the effect of season and year on floristic diversity (but see Muratet et al, 2009). Regardless, this standardized method permitted us to have comparable replicates that were sampled at the same time in similar surfaces and that differ only on the local practices applied to them and to the landscape surrounding them.…”

“…This value could not be taken as the full diversity present on Parisian lawns because species richness depend on the number of seasons and years sampled (Muratet et al, 2009) and further research is needed to evaluate temporal changes in the effects of lawn management practices. However it can be compared to studies with similar sampling effort as Thompson, Hodgson, Smith, Warren, and Gaston (2004) who, despite including bryophytes and small trees, observed 159 species (1.5 species/m 2 ) in 52 English lawns, while Stewart et al (2009) found only 127 herbaceous species (0.3 species/m 2 ) in 327 residential lawns in New Zealand.…”

Effort d’échantillonnage et atlas floristiques – exhaustivité des mailles et caractérisation des lacunes dans la connaissance

“…Des donne ´es bibliographiques, notamment historiques, issues de la saisie de publications naturalistes, d'herbiers ou de rapports d'e ´tudes sont aussi inte ´gre ´es a `la base. Il en re ´sulte une base de donne ´es conse ´quentes de pre `s de cinq millions de donne ´es mais assez he ´te ´roge `ne quant a `l'origine des donne ´es, aux protocoles de recueil et a `l'effort d'e ´chantillonnage [17].…”