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Conservation planners represent many aspects of biodiversity by using surrogates with spatial distributions readily observed or quantified, but tests of their effectiveness have produced varied and conflicting results. We identified four factors likely to have a strong influence on the apparent effectiveness of surrogates: (1) the choice of surrogate; (2) differences among study regions, which might be large and unquantified (3) the test method, that is, how effectiveness is quantified, and (4) the test features that the surrogates are intended to represent. Analysis of an unusually rich dataset enabled us, for the first time, to disentangle these factors and to compare their individual and interacting influences. Using two data-rich regions, we estimated effectiveness using five alternative methods: two forms of incidental representation, two forms of species accumulation index and irreplaceability correlation, to assess the performance of 'forest ecosystems' and 'environmental units' as surrogates for six groups of threatened species-the test features-mammals, birds, reptiles, frogs, plants and all of these combined. Four methods tested the effectiveness of the surrogates by selecting areas for conservation of the surrogates then estimating how effective those areas were at representing test features. One method measured the spatial match between conservation priorities for surrogates and test features. For methods that selected conservation areas, we measured effectiveness using two analytical approaches: (1) when representation targets for the surrogates were achieved (incidental representation), or (2) progressively as areas were selected (species accumulation index). We estimated the spatial correlation of conservation priorities using an index known as summed irreplaceability. In general, the effectiveness of surrogates for our taxa (mostly threatened species) was low, although environmental units tended to be more effective than forest ecosystems. The surrogates were most effective for plants and mammals and least effective for frogs and reptiles. The five testing methods differed in their rankings of effectiveness of the two surrogates in relation to different groups of test features. There were differences between study areas in terms of the effectiveness of surrogates for different test feature groups. Overall, the effectiveness of the surrogates was sensitive to all four factors. This indicates the need for caution in generalizing surrogacy tests.

Patterns in the spatial distribution of organisms provide important information about mechanisms that regulate the diversity of life and the complexity of ecosystems 1 , 2 . Although microorganisms may comprise much of the Earth's biodiversity 3 , 4 and have critical roles in biogeochemistry and ecosystem functioning 5 , 6 , 7 , little is known about their spatial diversification. Here we present quantitative estimates of microbial community turnover at local and regional scales using the largest spatially explicit microbial diversity data set available (> 10 6 sample pairs). Turnover rates were small across large geographical distances, of similar magnitude when measured within distinct habitats, and did not increase going from one vegetation type to another. The taxa–area relationship of these terrestrial microbial eukaryotes was relatively flat (slope z = 0.074) and consistent with those reported in aquatic habitats 8 , 9 . This suggests that despite high local diversity, microorganisms may have only moderate regional diversity. We show how turnover patterns can be used to project taxa–area relationships up to whole continents. Taxa dissimilarities across continents and between them would strengthen these projections. Such data do not yet exist, but would be feasible to collect.

Microbial diseases are important selective agents in social insects and one major defense mechanism is the secretion of cuticular antimicrobial compounds. We hypothesized that given differences in group size, social complexity, and nest type the secretions of these antimicrobials will be under different selective pressures. To test this we extracted secretions from nine wasp species of varying social complexity and nesting habits and assayed their antimicrobial compounds against cultures of Staphylococcus aureus. These data were then combined with phylogenetic data to provide an evolutionary context. Social species showed significantly higher (18x) antimicrobial activity than solitary species and species with paper nests showed significantly higher (11x) antimicrobial activity than those which excavated burrows. Mud-nest species showed no antimicrobial activity. Solitary, burrow-provisioning wasps diverged at more basal nodes of the phylogenetic trees, while social wasps diverged from the most recent nodes. These data suggest that antimicrobial defences may have evolved in response to ground-dwelling pathogens but the most important variable leading to increased antimicrobial strength was increase in group size and social complexity.

We investigated three procedures that may lead to rapid and accurate assessment of epigaeic arthropod biodiversity. They are: (1) the identification of taxa whose diversity is correlated with that of others: (2) the identification of times and methods of sampling that produce estimates of diversity representative of more intensive sampling; and (3) the use of morphospecies inventories generated by non-specialists. Ants, beetles, and spiders were sampled from four forest types, in three seasons, using two collecting methods: pitfall trapping and extraction from litter. Specimens were sorted by a non-specialist to morphospecies and by specialist taxonomists to species. Richness ($\\alpha$-diversity) and turnover ($\\beta$-diversity) were compared for different sampling regimes using morphospecies and species inventories. We found no significant positive correlations between ant, beetle, and spider species richness but there was a strong negative correlation between ant and beetle richness. For beetles alone, richness within the families Carabidae, Scarabaeidae, and Pselaphidae (i.e, avoiding taxonomically problematic families) was significantly correlated with richness within all other families. Assessment of turnover revealed that: (1) the four forest types contained significantly different assemblages of ants and beetles but not spiders and 92) the four forests were less clearly discriminated using species from the three beetle families Carabidae, Scarabaeidae, and Pselaphidae when compared to species from all beetle families pooled. Analyses of single sampling periods and methods revealed that summer and spring pitfall samples were most representative of more intensive sampling. That is: (1) the richness of ants and beetles in these samples was significantly positively correlated with the richness of all other samples and 92) turnover of beetles and ants among the four forests revealed by summer pitfall samples was similar to turnover using all samples. The three beetle surrogate families recorded by pitfall samples in spring, and to a lesser extent summer, showed significant correlations in richness with all other beetle species recorded in the same samples. However, the assessment of turnover was less accurate when only surrogate families were used. The most accurate and cost-effective assessment of turnover was generated by a summer pitfall sample in which data for ants, carabid, and scarab beetles were combined and analyzed as a single data set. Results were largely consistent regardless of whether species or morphospecies were used, which suggests that monitoring and assessment of terrestrial invertebrate biodiversity may be achieved by the careful use of morphospecies. Our results also suggest those invertebrate taxa, sampling methods, and sampling periods that yield the most consistent and reliable assessment of epigaeic invertebrate biodiversity in Australian temperate hardwood forests. However, empirical studies that follow the protocols discussed in this paper are urgently required in different environments. These studies may point the way to more representative monitoring and assessment of terrestrial biodiversity.

Environmental monitoring and conservation evaluation in terrestrial habitats may be enhanced by the use of invertebrate inventories, but taxonomic and logistic constraints frequently encountered during conventional taxonomic treatment have greatly restricted their use. To overcome this problem we suggest that nonspecialists may be used to classify invertebrates to morphospecies without compromising scientific accuracy. To test this proposition, large pitfall and litter samples of ants, beetles, and spiders from four forest types were sorted to morphospecies by a nonspecialist and to species by specialists. These data were used to generate morphospecies and species inventories and to estimate richness (α diversity) and turnover (β diversity), information frequently used in the above activities. Our results show that the estimates of richness of ants and spiders varied little between morphospecies and species inventories. Differences between estimates of beetle richness were largely influenced by errors of identification in two families, Curculionidae and Staphylinidae. But morphospecies and species inventories yielded identical ranking of forest type using richness. Turnover was assessed by sample ordination, which revealed similar clusters regardless of the type of inventory. Analysis of similarities of assemblages of ants and beetles showed significant differences between all forest types. Spider assemblages showed a lower level of discrimination. The assessment of turnover was consistent among inventories but different between the major taxa. Our findings suggest that morphospecies may be used as surrogates for species in some environmental monitoring and conservation, in particular when decisions are guided by estimates of richness and the assessment of turnover.

Only orchids affect pollination by the deceptive sexual attraction of male insects, a syndrome particularly well developed in Australia. We examined the ecological and genetic consequences of exclusive pollination by sexually attracted male thynnine wasps in the orchid Caladenia tentaculata. Male wasps respond rapidly to flowers artificially presented in 1 x 1 m2experimental patches. Sixty of 287 wasps approached within centimeters of the flower, but did not land. Of the remaining 79% who made floral contact, only 7.5% attempted copulation, the step critical for pollination. Wasps only rarely moved among patches (19% of flights) and none attempted copulation a second time, resembling observations in natural populations. We confirmed outcrossing and long distance pollen flow by monitoring how colored pollen moved in natural populations. Pollen movements approximated a linear rather than a leptokurtic distribution (mean distance: 17 m; maximum: 58 m). Pollinator visits varied independently of flower density in three of four populations with most solitary flowers being visited. Allozyme analysis revealed within-population fixation indices (F) close to zero and low levels of differentiation (FST) among populations. Despite behavioral evidence for long distance pollen flow, significant local genetic structure exists, perhaps reflecting restricted seed dispersal. Long distance pollen flow in C. tentaculata may therefore promote outbreeding by minimizing pollen transfers among related neighbors. Although this species is self-compatible, outcrossed progeny develop significantly faster than selfed progeny Effective pollination at low flower densities could accentuate this advantage. The data are consistent with the predictions that deceptive pollination will result in long distance pollen flow, which may be of selective advantage at low density Comparative studies of how food reward, food deceptive, and sexual deceptive pollination systems vary within a phylogenetic framework could further illuminate the evolution of sexual deception.

An important issue in conservation biology is the extent to which one group of organisms can function as a surrogate for less well-known groups. We explored the extent to which vascular plant species diversity (both α-diversity, or species richness, and β-diversity, or turnover) and the subgroups of understory, overstory, and ferns can act as surrogates for bryophyte and lichen species diversity. We surveyed 35 sites in a range of forest types in the coastal lowlands of eastern Australia. Fern species richness was strongly positively correlated with bryophyte species richness but negatively correlated with lichen species richness. Fern, bryophyte, and lichen species richness all varied significantly with time since fire, vascular plant cover, and topographic position gradients. Of the other vascular plant groups, the only significant correlation was between overstory and bryophyte species richness. We quantified species turnover using modifications of Whittaker's original measure as well as multivariate techniques. The rate of lichen species turnover was the lowest of all six groups investigated. The other five groups had similar rates of species turnover, although the results were different depending on the emphasis of the measure used. There were significant correlations between the patterns of species turnover of bryophytes and lichens and those of all four vascular plant groups, but none of the correlations was particularly strong. The understory and all vascular plants were the best predictors of the species turnover pattern of bryophytes and lichens, and correlations appeared strongest in wet sclerophyll sites. With respect to management practices, time since the last fire appears to be an important determinant of bryophyte, lichen, and vascular plant diversity, and logging appears to differentially affect the diversity of the different plant categories. A mosaic of logging and fire intervals and intensities appears to be important for maintaining regional diversity.

The ability to extrapolate from the known to the unknown is essential if we are to use the turnover of overall biodiversity, as opposed to a few well-known groups, to inform conservation planning. We investigated the usefulness of using evolutionary relationships of plants as a surrogate for the turnover of their associated beetle assemblages. If plant traits that are important to insects are phylogenetically conserved, it follows that there will be a positive relationship between insect faunal dissimilarity and plant evolutionary distance. We collected beetles using pyrethrum knock-down methods from 40 plant species belonging to four plant families in the Sydney region of Eastern Australia. We developed a novel approach for estimating variance in the dissimilarity of beetle assemblages, as explained by plant phylogeny, by using phylogenetic eigenvectors as explanatory variables in a distance-based redundancy analysis. We found a highly significant relationship between faunal dissimilarity and plant evolutionary distance for the entire beetle assemblage, the herbivorous component, and the non-herbivorous component, indicating that beetles generally showed some preference for particular plant clades as habitat, regardless of feeding guild. When comparing observed dissimilarities with those predicted from 40 jack-knife replicates of a Generalised Dissimilarity Model, we were often able to predict beetle turnover from plant phylogenetic relationships, although the reliability of this result was highly variable. Nevertheless, the broad response of beetle assemblages to plant evolutionary relatedness indicates real potential for plant phylogenetic pattern to act as a useful surrogate for insect biodiversity, especially when supplemented with other environmental correlates.