Environmental correlates of plant and invertebrate

Authors: Christopher Hassall Jim Hollinshead Andrew Hull

Publish Date: 2011/08/31

Volume: 20, Issue: 13, Pages: 3189-3222

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Abstract

Ponds lentic water bodies 2 ha constitute a considerable biodiversity resource Understanding the environmental factors that underlie this diversity is important in protecting and managing the habitat We surveyed 425 ponds for biological and physical characteristics with 78 of those also surveyed for chemical characteristics A total of 277 invertebrate species and 265 plant species were found Species richness varied between 2 and 99 mean 272 ± 06 SE for invertebrates and 1 and 58 mean 208 ± 04 SE for plants Generalised additive models were used to investigate variables that correlate with the species richness of plants and invertebrates with additional models to investigate insect Coleoptera Odonata Hemiptera Trichoptera and Mollusca species richness Models performed reasonably well for invertebrates in general R 2 = 303 but varied between lowerorder invertebrate taxa 127–347 Ponds with lower levels of shading and no history of drying contained higher numbers of species of plants and all invertebrate groups Aquatic plant coverage positively correlated with species richness in all invertebrate groups apart from Trichoptera and the presence of fish was associated with high invertebrate species richness in all groups apart from Coleoptera The addition of chemistry variables suggested nonlinear relationships between oxygen demand and phosphate concentration and higherorder richness We demonstrate that the composition of biological communities varies along with their species richness and that less diverse ponds are more variable compared to more diverse ponds Variables positively correlated with richness of one taxon may be negatively correlated with that of another making comprehensive management recommendations difficult Promoting a high landscapelevel pond biodiversity will involve the management of a high diversity of pond types within that landscapeThe Pond Life Project is funded by the Life Programme of the European Union and a consortium of partners including Cheshire County Council with Warrington and Vale Royal Borough Councils We are indebted to Jonathan Guest and David Bentley for their efforts in carrying out the pond surveys CH was supported by a Government of Canada Postdoctoral Research FellowshipFitted relationships between residuals of the generalised additive mixedeffects models GAMMs and each predictor variable from the first analysis physical and biological predictors n = 425 Solid lines are fitted splines in the eight continuous variables and fitted values for each of the two categorical variables Dotted lines are 1SE Tick marks on the xaxis indicate values of the predictorsFitted relationships between residuals of the generalised additive models GAMs and each predictor variable from the second analysis physical chemical and biological predictors n = 78 Solid lines are fitted splines in the eight continuous variables and fitted values for each of the two categorical variables Dotted lines are 1SE Tick marks on the xaxis indicate values of the predictors

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