Non-lethal rapid biodiversity assessment

For several animal taxa, non-lethal techniques that do not rely on collecting individuals are routinely used to assess biodiversity (e.g. point counts in birds). Identification often relies on the ability of the observer, are subjected to errors, but populations are not impacted. Thus, multiple counting sessions (MCS) that allow using robust analyses (e.g. unbiased Chao richness estimate) are available. However, for most species (e.g. arthropods), trap systems must be set up. Killed individuals are collected and later accurately identified in the laboratory, but unbiased MCS become unavailable. Environmental DNA bar-coding provides an alternative, yet it requires important technical support and is not designed for MCS. Lethal rapid biodiversity assessments (RBA), derived from classical trap surveys and based on less accurate identifications (morphospecies are used), have been successfully developed to relax technical constraints. In this study, we combined non-lethal and RBA approaches to address logistical, analytical and ethical issues. We tested five versions of a protocol to visually survey the macro-fauna of hedgerows. A large number of individuals were directly identified in the field, mostly arthropods but also vertebrates. Identification error varied with taxonomic level and lineage, but remained low at the morphospecies level. Importantly, estimates tended to reach asymptotes, suggesting that local richness was appropriately appraised. Like any technique, non-lethal RBA (NL-RBA) present both advantages and weaknesses, and may improve the toolbox to survey biodiversity.     

Environmental factors affecting the distribution of aquatic invertebrates in temporary ponds in Mammoth Cave National Park,Kentucky, USA

Despite a recent surge of interest in temporary lentic systems, a strong theory linking the biota to its environment has not emerged. Using data from 10 temporary ponds at Mammoth Cave National Park, Kentucky, USA, we investigated how invertebrate communities were structured along environmental gradients, both between and within ponds. Samples were collected with a benthic corer in winter and spring, and a sweep net in spring. Six between-pond and two within-pond datasets were created. Between-pond analyses yielded significant CCA’s with only one of the six data sets. The ranges of environmental variables (EV’s) within ponds were often similar to the ranges of EV’s when averaged and compared between ponds. Some taxa were aggregated in a single pond, and richness increased with pond area. The theory that richness increases with hydroperiod did not apply to these systems. Within-pond analyses yielded more consistent relationships, with both CCA’s being significant. Sample depth was the best predictor of invertebrate richness and abundance, with most taxa preferring shallow habitats. Richness and abundance were higher in both shallow ponds and shallow areas of deep ponds than in deep areas of deep ponds. Standardizing sample depth may be an effective way to remove this gradient as a confounding variable in future research. The presence of within-pond gradients, possibly coupled with the limited dispersal and random colonization of tolerant taxa, makes between-pond comparisons difficult. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorised users. Handling editor: S. Declerck     

Consistency and variation in kelp holdfast assemblages: Spatial patterns of biodiversity for the major phyla at different taxonomic resolutions

The focus of this study was to measure natural spatial variability in the biodiversity of fauna inhabiting kelp holdfasts in northeastern New Zealand at several spatial scales: from meters up to hundreds of kilometers. We wished to test the hypothesis that multivariate variation and biodiversity would vary significantly at different spatial scales in different ways for the major phyla in the holdfast community (Arthropoda, Annelida, Mollusca and Bryozoa). Biodiversity was considered in terms of richness, total abundance, structural composition (as measured by the Bray-Curtis dissimilarity measure) and taxonomic breadth for each major phylum and for the assemblage as a whole. We also examined the effect of taxonomic resolution on multivariate patterns. Species richness and total abundance increased with increases in holdfast volume. Multivariate variation was greatest at the smallest spatial scale for all phyla, but different phyla showed different patterns of multivariate variation at different spatial scales. Variations among locations at the largest spatial scale were primarily due to differences in the composition and richness of bryozoans and molluscs. Location effects became less and less distinct with decreases in taxonomic resolution. There were very few significant differences in richness or abundance for holdfasts of a given volume, taxonomic breadth did not vary significantly across locations, nor did the proportional abundances of phyla. These consistencies across large spatial scales in the absence of environmental impacts and results from other studies suggest that holdfast communities in New Zealand systems would provide a useful model assemblage against which future impacts may be detected as changes in proportions of component phyla. In addition, high variability detected at small and large scales at the species level, especially for bryozoans and molluscs, suggest that these communities may also provide unique opportunities for studying and understanding sources and functions of marine biodiversity.     

Using a goal programming approach to design and evaluate protected areas for the conservation of multiple dimensions of biodiversity

The decline and loss of biodiversity provoked by human activities have caused ecologists and conservationists to center their attention on the design of conservation priority areas (PAs), focusing mainly on species conservation in terms of richness, rarity and/or vulnerability. However, biodiversity has multiple dimensions, evolutionary processes have recently been labeled the ‘missing component’ of conservation strategies, and increasingly more authors are suggesting that the ecological, evolutionary and historical aspects of biodiversity are key components of conservation planning. In this study we develop a prioritization system to design conservation PAs using the wild terrestrial mammals of the Iberian Peninsula as an example. We aim to contribute to the design of more suitable PAs by integrating ecological components of biodiversity (species richness, vulnerability and rarity), evolutionary aspects (accumulated genetic diversification) and historical information relevant to the study area. After selecting a set of biodiversity indicators, we applied a multi-objective technique (extended goal programming) to construct a combined index, where values in the top 90th percentile were then used to select the PAs. According to our most efficient and satisfactory results, some areas highlighted for their conservation are currently categorized as PAs, however, we found that it would be necessary to reconsider their extent, especially in northern Spain, where the historical aspects of biodiversity (the missing component) are more widely present. The need to determine PAs is unquestionable. However, it should also be a priority to move towards a model of sustainable and fair development.     

Richness, Abundance, and Complementarity of Fruit-feeding Butterfly Species in Relict Sacred Forests and Forest Reserves of Ghana

Sacred forest groves in Ghana are centuries old protected areas that were once part of continuous forest cover but now mostly exist as relict forest patches embedded in an agropastoral landscape. We conducted a year-long survey of the fruit-feeding butterfly fauna of four sacred groves and two forest reserves in the moist semi-deciduous forest zone of Ghana to characterize resident species diversity and complementarity among communities. Joint analysis of frugivorous butterfly diversity at these six forest fragments, which ranged in size from 6 to 5000 ha, was used to evaluate the conservation potential of these ancient indigenous reserves. A total of 6836 individuals were trapped across all sites, representing 79 species and five subfamilies. Community diversity was characterized in terms of, (a) number of species accumulated versus sampling effort, (b) rarefied species richness, (c) nonparametric richness estimates, (d) species evenness, (e) Simpson’s Index of Diversity, and (f) complementarity of communities. Diversity of the fruit-feeding butterfly communities, quantified in terms of both species evenness and rarefied species richness, was higher at the larger forest reserves than at the small sacred forest groves. Additionally, although all sites had species trapped only at that site, the 5000-ha forest reserve harbored a resident community that was clearly distinctive from and more diverse than the other communities including the other forest reserve. Hence, our findings add to the burgeoning body of data that indicates large reserves are the foundation of successful conservation programs. Nonetheless, we found these small forest patches contribute to biodiversity conservation in at least three ways and these are identified and discussed. We also identify a number of species that appear more or less vulnerable to dynamics of forest fragmentation based on changes in their relative abundance across sites and we interpret these data in the context of potential indicator species and theoretical predictions of at-risk species.     

Structure and dynamics of the periphytic algae of Jinyang Lake in Shanxi Province, North China

The structure and dynamics of periphytic algae in Jinyang Lake, the largest man-made lake in Taiyuan, Shanxi, have been studied by examining the periphytic algae samples collected from four sampling stations, during March 2006 to February 2007. In total, 227 species of periphytic algae (including varieties), belonging to three divisions, 27 families, 62 genera, have been identified. Diatoms were the dominant periphytic algae group. Taken the Shannon–Weaver, Margalef and Simpson diversity index together, it showed obvious temporal and spatial dynamics among different seasons and different sampling stations. The highest periphytic community structure evenness appeared at sampling station I in spring, summer and autumn, while at sampling station III in winter. The average biomass of periphytic algae varied from seasons. Our data showed that major factors affecting the periphytic algae in Jinyang Lake was water temperature, nutrient levels as well as human activities. In addition, the main effect caused by thermal power plant has been discussed.     

Ecology of pollination in a tropical Venezuelan savanna

Pollination modes ecology of a total of 164 plant species was evaluated according to habitats and plant life forms in the Venezuelan Central Plain. Frequency distribution of nine pollination modes showed that, at the community level bee pollination (38.6%) was dominant. Butterfly (13.9%), fly (12.7%), and wasp (10.8%) pollination were the second most frequent. Moth (6.2%) and wind (10.4%) pollination occurred with similar frequency, and the least common were bird (3.1%), beetle (2.3%) and bat (1.9%) pollination. There was a significant interaction effect indicating that pollination mode was affected by the type of habitat. Bee pollination was the most common pollination mode in all habitats with butterfly, fly and wasp pollination being secondary for forest and forest-savanna transition; and butterfly, wasp, wind and fly pollination being secondary for savanna. Wind, butterfly and fly pollination were found in disturbed areas as secondary pollination modes. Pollination modes were significantly associated and affected by life forms. Bee pollination was dominant in all life forms with wasp, butterfly and fly pollination being the secondary for trees, shrubs, and lianas; and butterfly and wind pollination being the secondary for herbaceous species. The number of pollination modes (richness) among life forms ranged between four and nine for epiphytes and perennial herbs respectively. The highest values of diversity indexes among life forms were found in trees and shrubs. The richness and diversity indices of pollination modes were statistically higher for more structured habitats, forest and forest-savanna transition, than herbaceous habitats, savanna and disturbed areas, which is associated with the highest values of diversity indexes in trees and shrubs. Equitability was higher for forest and disturbed areas than forest-savanna transition and savanna. The results of comparative richness, equitability, diversity indices, and the frequency distribution of pollination modes of 19 samples from tropical and temperate communities indicated that richness of pollination modes may be different between tropical and temperate communities. The proportion of each pollination mode suggests four grouping: (1) rain forests and their strata, (2) grassland savanna, and associated disturbed areas, (3) temperate communities, and (4) the most heterogeneous group, contained mostly neotropical communities, including the four habitats of the Venezuelan Central Plain. The frequency of pollination modes, richness, diversity and equitability of communities, habitats, successional stages, and vegetation strata varies with respect to geography, vegetation structure, and plant species richness.     

Relationships between biodiversity and biological control in agroecosystems: Current status and future challenges

Agricultural systems around the world are faced with the challenge of providing for the demands of a growing human population. To meet this demand, agricultural systems have intensified to produce more crops per unit area at the expense of greater inputs. Agricultural intensification, while yielding more crops, generally has detrimental impacts on biodiversity. However, intensified agricultural systems often have fewer pests than more “environmentally-friendly” systems, which is believed to be primarily due to extensive pesticide use on intensive farms. In turn, to be competitive, less-intensive agricultural systems must rely on biological control of pests. Biological pest control is a complex ecosystem service that is generally positively associated with biodiversity of natural enemy guilds. Yet, we still have a limited understanding of the relationships between biodiversity and biological control in agroecosystems, and the mechanisms underlying these relationships. Here, we review the effects of agricultural intensification on the diversity of natural enemy communities attacking arthropod pests and weeds. We next discuss how biodiversity of these communities impacts pest control, and the mechanisms underlying these effects. We focus in particular on novel conceptual issues such as relationships between richness, evenness, abundance, and pest control. Moreover, we discuss novel experimental approaches that can be used to explore the relationships between biodiversity and biological control in agroecosystems. In particular, we highlight new experimental frontiers regarding evenness, realistic manipulations of biodiversity, and functional and genetic diversity. Management shifts that aim to conserve diversity while suppressing both insect and weed pests will help growers to face future challenges. Moreover, a greater understanding of the interactions between diversity components, and the mechanisms underlying biodiversity effects, would improve efforts to strengthen biological control in agroecosystems.     

Avian richness and abundance in temperate Danish forests: tree variables important to birds and their conservation

Many studies on avian diversity and forest structure have focused onfiner scale forest variables such as foliage height diversity, foliagediversity, foliage density, vertical distribution of vegetation and horizontalvegetation density. From a conservation and forestry operational point of viewit would be of great interest if tree variables influenced directly by forestrymanagement decisions also had significant influence on avian richness andabundance. The species, age and size of a tree are examples of such treevariables. A great number of studies also have focused on avian diversityindices to reveal relationships with vegetation variables. However, it may bemore appropriate for foresters and conservation officers to operate withrichness and abundance measures directly, because indices complicateinterpretations on the relative importance of the two variables (richness andabundance) constituting the index. Fourteen managed temperate forests in Denmarkwere investigated for avian species richness and abundance and related tomeasures on different tree variables influenced directly by forestry managementdecisions. A rapid assessment method of avian richness and abundance wasemployed. It consisted of point-counts of bird richness and abundance within 1km² of forest. General linear models were tested byanalyses of variance statistics to reveal the tree variables most important toavian richness and abundance. It was found that more old trees, more treespecies and more tree size-classes correlated with more bird species andindividuals. However, some variation in bird richness and abundance was alsorelated to site quality and/or chance colonization. Moreover, it was shown thatthe guild of cavity-nesting birds correlated positively to age of tree stand.The potential number of bird species in Danish forest is similar to that innearly pristine forest in Poland, and much larger than that recorded in any ofthe forests investigated. Together with the results above, this indicates a highpotential for squeezing in more avian species in a higher quality forest from abiodiversity point of view. Modern Danish forestry affects tree variablesinfluenced directly by forestry management decisions. Such tree variables havegreat influence on avian richness and abundance, but simple measures in forestrypractices can be taken to enhance the conservation of bird richness andabundance.