Surrogates For Species Richness Research Articles

Taxones superiores de hormigas como sustitutos de la riqueza de especies, en una cronosecuencia de bosques secundarios, bosque primario y sistemas agroforestales en la Amazonía Oriental, Brasil

Deforestation in Amazon forests is one of the main causes for biodiversity loss worldwide. Ants are key into the ecosystem because act like engineers; hence, the loss of ants’ biodiversity may be a guide to measure the loss of essential functions into the ecosystems. The aim of this study was to evaluate soil ant’s richness and to estimate whether higher taxa levels (Subfamily and Genus) can be used as surrogates of species richness in different vegetation types (fallows, old-growth forests and agroforestry systems) in Eastern Amazon. The samples were taken in 65 areas in the Maranhão and Pará States in the period 2011-2014. The sampling scheme followed the procedure of Tropical Soil Biology and Fertility (TSBF). Initially, the vegetation types were characterized according to their age and estimated species richness. Linear and exponential functions were applied to evaluate if higher taxa can be used as surrogates and correlated with the Pearson coefficient. In total, 180 species distributed in 60 genera were identified. The results showed that ant species richness was higher in intermediate fallows (88) and old secondary forest (76), and was lower in agroforestry systems (38) and mature riparian forest (35). The genus level was the best surrogate to estimate the ant’s species richness across the different vegetation types, and explained 72-97 % (P < 0.001) of the total species variability. The results confirmed that the genus level is an excellent surrogate to estimate the ant’s species richness in the region and that both fallows and agroforestry systems may contribute in the conservation of Eastern Amazon ant community.

Freshwater vertebrate and invertebrate diversity patterns in an Andean-Amazon basin: implications for conservation efforts

The Napo Basin in Ecuador is an important drainage of the Amazon Basin, the most biodiverse ecosystem for freshwater species. At the same time, this basin has conspicuous information gaps on its biodiversity patterns and human threats. Here, we estimated the diversity distribution patterns of freshwater vertebrates and invertebrates in the Napo Basin, as a tool for present and future management and conservation efforts. Also, we assessed the spatial congruence of the diversity patterns observed between aquatic vertebrates and invertebrates. For this, we compiled occurrence records for 481 freshwater vertebrate species (amphibians, birds, mammals, reptiles, and fish), and 54 invertebrate families obtained across an altitudinal gradient of the basin (200–4500 m). Using these occurrence records and environmental variables, we modeled the distribution of each vertebrate species and invertebrate family. Then, we stacked these distributions to build species richness maps for vertebrates, and a family richness map for invertebrates. We found that the most diverse areas for vertebrate species are the lowlands (<600 m), whereas richness of invertebrate families peaks at higher elevations (lower montane forests). Congruence among species richness patterns of the five vertebrate groups was high (r = 0.66), with fish being the best predictor for vertebrates (r = 0.78). However, congruence decreased at higher elevations (r = 0.14), suggesting that specific species or habitat-based approaches should be used in the highlands. Also, we found a high correlation between species and family richness of freshwater invertebrates (r = 0.66), suggesting that family richness of invertebrates could be used as a surrogate of species richness in this basin. We highlight this correlation because, at the watershed scale, it allows working with family groups where species-level taxonomy is challenging. Our results provide the first comprehensive representation of freshwater biodiversity patterns at high resolution in an Andean-Amazon basin, and calls attention to the need for incorporating different taxonomic groups when assessing diversity patterns. Given these different diversity patterns, conservation programs for this basin should incorporate both vertebrate and invertebrate groups as biodiversity indicators. Finally, our study provides a practical methodological guidance in the estimation of freshwater diversity in regions of scarce information with high conservation priority, such as the Andean-Amazon basins.

Taking shortcuts to measure species diversity: parasitoid Hymenoptera subfamilies as surrogates of species richness

When trying to assess entomological diversity, identifying taxa at levels higher than species is much easier and may provide a wider vision of other ecological features. In this work, we used the data from several samplings made in across six cacao farms in Merida state (Venezuela). Farms fell into two categories according to intensity of perturbation. In these samplings we identified all parasitoid Hymenoptera families. All individuals belonging to families Ichneumonidae, Braconidae and Chalcididae were sorted to subfamilies and then to morphospecies. The accuracy of subfamilies richness to predict the species richness and to detect differences in the conservation status of plantations was tested. The species aggregation according to the sampling size was also explored. The three families this study was focused on represented 23 % of the total sampling, comprising 40 subfamilies and 393 morphospecies. Results showed a significant high positive correlation between subfamilies and species richness, and species/subfamilies ratio was about 4.5:1, with logarithmic relationship with sampling size tending to stabilisation at sizes greater than 15 individuals per sampling day. Subfamily richness detected the nearly-significant differences in plantations with the same accuracy as species richness, and therefore surrogacy effectiveness of parasitoid Hymenoptera subfamilies richness may be accepted for cacao plantations.

The use of a functional approach as surrogate of Collembola species richness in European perennial crops and forests

Collembolans are known indicators of soil disturbance, used in several soil biodiversity monitoring programmes. As for other groups of soil microarthropods, taxonomic determination of Collembola species requires a huge effort and expert knowledge. In this study, we evaluated whether identification of Collembola species to the morphotype level, using an eco-morphological index which classifies individuals based on their adaptation to the soil, can be used as a surrogate of species richness in extensive monitoring schemes. The same evaluation was performed for higher taxa surrogates, using taxonomic categories at the genus and family levels. Additionally, sampling effort for perennial crops and forest systems was determined. Species data were collected from 35 sites sampled within different projects with the same number of samples (16 per site). Results showed that, on average, 8–12 samples are enough to have a good estimate of species richness for this type of systems, averaging 80–90%, but varying considerably with site habitat heterogeneity and local Collembola species pool. GLM models (using species richness as response variable) fitted for family, genus or morphotype levels (explanatory variables) were all significant (p<0.05) but only the latter two had a pseudo R2 higher than 0.75. This indicates that when a rapid, cost-effective assessment of Collembola richness in different sites is required, this eco-morphological trait approach, as well as the determination to the genus level, could be used.

Satellite‐derived vegetation indices as surrogate of species richness and abundance of ground beetles in temperate floodplains

Abstract Remotely sensed data are frequently employed for monitoring vegetation and for estimating herbivore diversity. Their use for predicting predator arthropod species abundance and richness has also been investigated with success for ants and beetles in forests using normalised difference vegetation index (NDVI) and for beetles in mountain forests using light detection and ranging data. We investigated whether vegetation indices, derived from multispectral SPOT imagery could predict abundance and species richness of ground active spiders and ground beetles in a new ecological context, the floodplain meadows of the Loire River in Western Europe. Using pitfall traps, we collected carabids and spiders in the field. Maximum vegetation height, litter‐depth and plant species richness best explained species assemblages of both groups (multivariate analyses). NDVI and enhanced vegetation index (EVI 2) were strongly related to activity‐density and species richness for ground beetles only, EVI 2 being the best surrogate. Relationships between vegetation indices and spider assemblage patterns were either non‐significant or weak. We demonstrated that EVI 2 is a good surrogate of the abundance and richness of carabid species in a temperate floodplain, and has potential as a low cost method for mapping arthropod assemblages at large spatial scales. Our approach provides a tool which contributes to biodiversity assessment at large spatial scales. It can also contribute to the prioritisation of conservation areas and early change detection, as carabids are keystone indicators.

A test for assessment of saproxylic beetle biodiversity using subsets of “monitoring species”

In European forests, large scale biodiversity monitoring networks need to be implemented – networks which include components such as taxonomical groups that are at risk and that depend directly on forest stand structure. In this context, monitoring the species-rich group of saproxylic beetles is challenging. In the absence of sufficient resources to comprehensively survey a particular group, surrogates of species richness can be meaningful tools in biodiversity evaluations. In search of restricted subsets of species to use as surrogates of saproxylic beetle richness, we led a case study in Western Europe.Beetle data were compiled from 67 biodiversity surveys and ecological studies carried out from 1999 to 2010 with standardised trapping methods in France and Belgium. This large-scale dataset contains 642 forest plots, 1521 traps and 856 species. Twenty-two simplified species subsets were identified as potential surrogates, as well as the number of genera, a higher taxonomic level, taking into account, for each surrogate, the effort required for species identification, the practical monitoring experience necessary, the species conservation potential or the frequency of species occurrence. The performance of each surrogate was analyzed based on the following parameters: overall surrogacy (correlation between subset richness and total species richness), surrogacy vs. identification cost balance, surrogacy variation over a wide range of ecological conditions (forest type, altitude, latitude and bio-geographical area) and consistency with spatial scale. Ecological representativeness and ability to monitor rare species were supplementary criteria used to assess surrogate performance.The subsets consisting of the identifiable (or only easy-to-identify species) could easily be applied in practice and appear to be the best performing subsets, from a global point of view.The number of genera showed good prediction at the trap level and its surrogacy did not vary across wide environmental gradients. However, the subset of easy-to-identify species and the genus number were highly sensitive to spatial scale, which limits their use in large-scale studies. The number of rare species or the species richness of single beetle families (even the best single-family subset, the Cerambycidae) was very weak surrogates for total species richness. Conversely, the German list of monitoring species had high surrogacy, low identification costs and was not strongly influenced by the main geographical parameters, even with our French and Belgian data.In European-wide monitoring networks, such internationally validated subsets could be very useful with regard to the timing and cost-efficiency of field inventories.

Broad-Scale Hypotheses do not Account for Species Richness Patterns of Central American Mayflies

I performed an exploratory analysis of four broad-scale hypotheses (area availability, energy availability, habi- tat heterogeneity and geometric constraints) for changes in species richness over Central American mayfly species, and compared their outcomes at different taxonomic levels. I employed an eigenvector-based spatial filtering to control spatial autocorrelation effects and conducted multiple spatial eigenvector regressions to identify the strongest predictors of spe- cies, genus and family richness. The usefulness of higher-taxa as surrogates for species richness was assessed by Pearson correlations. Mayfly species richness is characterized by a patchy pattern. None of the variables accounted for observed patterns. Only area availability was an effective predictor of mayfly genus and family richness, although both habitat het- erogeneity and energy presented marginal effects on genus richness. I did not observe any relationship between species and higher-taxa richness. Broad-scale hypotheses did not explain species richness patterns of mayflies, which instead can be explained by interactions among studied variables and spatial structure.

Coral Reef Habitats as Surrogates of Species, Ecological Functions, and Ecosystem Services

Habitat maps are often the core spatially consistent data set on which marine reserve networks are designed, but their efficacy as surrogates for species richness and applicability to other conservation measures is poorly understood. Combining an analysis of field survey data, literature review, and expert assessment by a multidisciplinary working group, we examined the degree to which Caribbean coastal habitats provide useful planning information on 4 conservation measures: species richness, the ecological functions of fish species, ecosystem processes, and ecosystem services. Approximately one-quarter to one-third of benthic invertebrate species and fish species (disaggregated by life phase; hereafter fish species) occurred in a single habitat, and Montastraea-dominated forereefs consistently had the highest richness of all species, processes, and services. All 11 habitats were needed to represent all 277 fish species in the seascape, although reducing the conservation target to 95% of species approximately halved the number of habitats required to ensure representation. Species accumulation indices (SAIs) were used to compare the efficacy of surrogates and revealed that fish species were a more appropriate surrogate of benthic species (SAI = 71%) than benthic species were for fishes (SAI = 42%). Species of reef fishes were also distributed more widely across the seascape than invertebrates and therefore their use as a surrogate simultaneously included mangroves, sea grass, and coral reef habitats. Functional classes of fishes served as effective surrogates of fish and benthic species which, given their ease to survey, makes them a particularly useful measure for conservation planning. Ecosystem processes and services exhibited great redundancy among habitats and were ineffective as surrogates of species. Therefore, processes and services in this case were generally unsuitable for a complementarity-based approach to reserve design. In contrast, the representation of species or functional classes ensured inclusion of all processes and services in the reserve network.

Taxonomic Resolution and Quantification of Freshwater Macroinvertebrate Samples from an Australian Dryland River: The Benefits and Costs of Using Species Abundance Data

In studies using macroinvertebrates as indicators for monitoring rivers and streams, species level identifications in comparison with lower resolution identifications can have greater information content and result in more reliable site classifications and better capacity to discriminate between sites, yet many such programmes identify specimens to the resolution of family rather than species. This is often because it is cheaper to obtain family level data than species level data. Choice of appropriate taxonomic resolution is a compromise between the cost of obtaining data at high taxonomic resolutions and the loss of information at lower resolutions. Optimum taxonomic resolution should be determined by the information required to address programme objectives. Costs saved in identifying macroinvertebrates to family level may not be justified if family level data can not give the answers required and expending the extra cost to obtain species level data may not be warranted if cheaper family level data retains sufficient information to meet objectives. We investigated the influence of taxonomic resolution and sample quantification (abundance vs. presence/absence) on the representation of aquatic macroinvertebrate species assemblage patterns and species richness estimates. The study was conducted in a physically harsh dryland river system (Condamine-Balonne River system, located in south-western Queensland, Australia), characterised by low macroinvertebrate diversity. Our 29 study sites covered a wide geographic range and a diversity of lotic conditions and this was reflected by differences between sites in macroinvertebrate assemblage composition and richness. The usefulness of expending the extra cost necessary to identify macroinvertebrates to species was quantified via the benefits this higher resolution data offered in its capacity to discriminate between sites and give accurate estimates of site species richness. We found that very little information (<6%) was lost by identifying taxa to family (or genus), as opposed to species, and that quantifying the abundance of taxa provided greater resolution for pattern interpretation than simply noting their presence/absence. Species richness was very well represented by genus, family and order richness, so that each of these could be used as surrogates of species richness if, for example, surveying to identify diversity hot-spots. It is suggested that sharing of common ecological responses among species within higher taxonomic units is the most plausible mechanism for the results. Based on a cost/benefit analysis, family level abundance data is recommended as the best resolution for resolving patterns in macroinvertebrate assemblages in this system. The relevance of these findings are discussed in the context of other low diversity, harsh, dryland river systems.

Higher Taxa as Surrogates of Plant Biodiversity in a Megadiverse Country

Abstract: An important question in conservation biology is the extent to which the number of taxonomic supraspecific categories can serve as surrogates of species richness. This issue has been little explored in highly diverse areas. We used 113 floristic inventories from throughout Mexico, a megadiverse country, to evaluate the potential of higher‐taxon richness for predicting local species richness of vascular plants. This large biodiversity data set includes the main vegetation types found across the country. In all, 247 families, 2,398 genera, and 11,890 species were used for the analysis, representing 99.6%, 90.2%, and 53.2% of the respective totals recorded in the country. We hypothesized that the number of genera and species would be accurately predicted by the richness of the higher taxon. To avoid getting spurious regressions resulting from the logical increase in lower‐taxon richness as a higher taxon becomes richer, we calculated new response variables by subtracting from the number of elements in the lower taxon group the number of those in the higher taxon; these variables were “excess species” (number of species minus number of genera or families) and “excess genera” (number of genera minus number of families). Our results indicate that genera provide very effective surrogates for estimation of local species richness (R2= 0.85), whereas families have a more limited potential for this purpose (R2= 0.64). The predictive capacity of the diversity of higher taxon increased when the analyses were constrained to particular vegetation types (maximum R2= 0.95 for genera). This surrogate method may be a valuable tool in locating and designing representative systems of protected areas for vascular plant diversity, especially in megadiverse countries, where conservation efforts are hindered by the lack of complete inventories and insufficient resources.

On the quality of soil biodiversity indicators: abiotic and biotic parameters as predictors of soil faunal richness at different spatial scales

Direct measurement of soil biodiversity is expensive, and therefore a substitution of measurement by indication is desirable. We analysed three large datasets for the potential to predict the diversity of soil faunal groups from other parameters. The datasets represent different spatial scales, namely grassland nematodes on an European scale, forest collembola on a regional scale, and grassland ants on a local scale. We tested two groups of parameters as possible surrogates for species richness: (1) environmental parameters, such as climate, soil and vegetation characteristics, and (2) community parameters, such as higher taxon richness, indicator taxa, and maximum dominance. Climate and soil parameters were significantly correlated with biodiversity in all datasets. However, in spite of the large variety of measurement types analysed, prediction quality of environmental variables was weak and the explained proportion of variance ranged generally below 50%. Richness was subject to considerable stochastic variation among subsamples (CV=20–60%) thereby evading a narrow correlation with environmental parameters. Higher taxon richness, based on taxa of intermediate hierarchical order, proved the best predictor of richness in collembola and nematodes explaining 55 and 89% of total variance, respectively. A combination of two ant species was the best predictor of ant richness explaining 59% of total variance. The authors conclude that a rough guess of soil faunal diversity can be cost-effectively derived from environmental data while an estimate of moderate quality can be obtained with reduced taxonomic effort. The precise richness of a soil community, however, is subject to autogeneous community dynamics, to biotic interactions with other populations, and to conditions in the past, and can therefore only be retrieved by immediate investigation of the community itself. Criteria for the quality of indicator parameters are discussed.

Using higher taxa as surrogates of species richness: a study based on 3700 Coleoptera, Diptera, and Acari species in Central-Hungarian reserves

Abstract The conservation of biodiversity needs to locate the most diverse sites. Species level is the most often considered taxonomic resolution. However, it is almost impossible to conduct a rapid species level survey of many hyperdiverse and difficult to identify taxa, mainly within arthropods, which are the main components of species richness. I tested whether higher taxa (genus and family) are good surrogates of species richness in three large and usually not surveyed groups in 16 reserves in Central-Hungary: Coleoptera (2415 spp), Diptera (1004 spp), and Acari (288 spp). Species richness of the reserves correlated strongly with both genus and family diversity for all groups. Species numbers also correlated between pairs of the three taxa, but not for genus and family numbers. Therefore, higher taxon diversity is a good surrogate of species diversity, but the diversity of one taxon can indicate the diversity of the other only at the species level. Die Konservation der Biodiversitat braucht die Lokalisation des vielfaltesten Platze. Der Artenstand ist die haufigst, bedachte Losung. Jedoch ist es fast unmoglich, eine schnelle Vermessung auf dem Niveau der Arten bei vielen hyperdiversen und schweridentifizierenden Taxa zu machen, besonders bei Insekten, die die Hauptkomponente der Artenvielfalt sind. Ich untersuchte, ob die hoheren Taxa (Genus und Familie) in drei grosen und normalweise nicht ermessten Gruppen auf 16 mittelungarischen Schutzgebieten gute Ersatze der Artenvielfalt sind: Coleoptera (2415 Spp), Diptera (1004 Spp), und Acari (288 Spp). Die Artenvielfalt der Schutzgebiete korrelierte stark mit beider Genus- und Familiediversitat fur alle Gruppen. Die Nummer der Spezies korrelierte auch zwischen der Paaren der drei Taxa, aber die Nummer von Genera und Familien nicht. Also die hocheste Taxondiversitat ist ein guter Ersatz der Speziesdiversitat, aber die Diversitat von einem Taxon kann die Diversitat von anderen Taxa nur auf Artenstand indizieren.

Mapping biodiversity using surrogates for species richness: macro-scales and New World birds

A number of surrogates have been suggested for predicting relative levels of biodiversity (typically expressed in terms of species richness) in areas for which this information is not available. However, to date there has been little attempt to perform direct and explicit empirical comparisons of their effectiveness. Here we examine the relative predictive value of some environmental variables and of the numbers of higher taxa, using the avifauna of the New World. Numbers of genera and families are found to have the strongest correlations with species richness, and to provide the best predictions of the numbers of species in areas of Central and South America on the basis of data for North America. Their effectiveness as surrogates may result from the fact that they themselves represent an alternative currency for expressing levels of biodiversity.