Sites Of High Conservation Value Research Articles

Specialised chemistry affects insect abundance but not overall community similarity in three rare shrub willows: Salix myrtilloides, S. repens and S. rosmarinifolia

Willows serve as a keystone host-plant genus for insect herbivores. The diversity of insect herbivore assemblages harboured by willows is typically affected by the diversity of specialised metabolites that willows produce. Here, we studied three small, shrubby willow species (Salix myrtilloides, S. repens and S. rosmarinifolia) that primarily occur at sites of high conservation value in the Czech Republic. We explored if associated insect communities reflect the specialised chemistry in these uncommon host plants. We measured the three willow species for overall metabolomic profiles and salicinoids using non-targeted metabolomics and sampled them for caterpillars, leaf-chewing beetles (adults and larvae), sawfly larvae, and sap-sucking Hemiptera. We detected 2,067 metabolites across the three willow species. Most of them were shared by S. repens and S. rosmarinifolia, while S. myrtilloides showed a distinct chemical profile. Salix repens and S. rosmarinifolia also had significantly higher concentration and richness of salicinoids than S. myrtilloides. The abundance of all insect species and generalists that also feed on host-plants outside Salicaceae was higher on S. myrtilloides than on S. rosmarinifolia or S. repens. The abundance of Salicaceae specialists did not differ among the three willow species. Insect community composition, in contrast, did not show pronounced differences among the three willows. Our results suggest that salicinoids may be responsible for the low abundance of generalist herbivores. Furthermore, our study indicates that herbivore community composition does not reflect the specialised chemistry in the three willows we studied. Therefore, we hypothesise that the presence of some of the insect species is primarily determined by other factors, such as the habitat type where the respective willow species occur. Although the studied willows possess some characteristic specialised chemistry, we conclude that their importance as hosts of specific and sometimes threatened insect fauna may be mediated by willow habitat preference.

Combined climatic and anthropogenic stress threaten resilience of important wetland sites in an arid region

Climate change and anthropogenic perturbation threaten resilience of wetlands globally, particularly in regions where environmental conditions are already hot and dry, and human impacts are rapidly intensifying and expanding. Here we assess the vulnerability of Ramsar wetlands of six North African countries (Western Sahara, Morocco, Algeria, Tunisia, Libya, and Egypt) by asking three questions: (1) what are the recent anthropogenic changes that the wetlands experienced? (2) what are the projected future climatic changes? (3) how wetlands with different conservation priorities and globally threatened species are impacted by anthropogenic pressures? We used climatic data (historical and future projections) from WorldClim 2, drought index (SPEI), and human footprint index (HFI for 2000 and 2019) to estimate anthropogenic pressures, as well as waterbird conservation value (WCV: a metric indicating conservation priority of sites) and the breeding distribution of three threatened waterbird species (Aythya nyroca, Marmaronetta angustirostris, and Oxyura leucocephala) to understand how biodiversity is impacted by anthropogenic pressure. We found that temperature, precipitation, drought, and human footprint index (HFI) increased during earlier decades. Interestingly, areas with high HFI are projected to encounter lower warming but more severe drought. We also found that WCV was positively correlated with the magnitude of current HFI, indicating that sites of high conservation value for waterbirds encounter higher levels of anthropogenic pressure. The breeding range of the three threatened species of waterbirds showed a marked increase in HFI and is projected to experience a severe increase in temperature by 2081–2100, especially under the high emission scenario (SSP8.5) where environmental temperature becomes closer to the species critical maximum. Our results highlight the importance of integrating new conservation measures that increase the resilience of North African protected wetlands to reduce extinction risk to biodiversity.

Climate Connectivity of European Forests for Species Range Shifts

Forest connectivity is important for the range shifts and long-term persistence of forest-dependent species, especially in the context of climate change. This study assessed the climate connectivity of European forests for species to track suitable climate conditions as the climate warms. Here, climate connectivity was calculated as the temperature difference between each forest patch and the coolest patch that can be reached along temperature gradients. We found that, overall, about 36% of the total forested area in Europe has achieved successful climate connectivity under the moderate emission scenario (SSP245), whereby species range shifts could circumvent the impact of climate warming. The percentage is much lower under the highest emission scenario (SSP585), which is only 12%. To identify forest areas of high importance for climate connectivity, we further evaluated the potential of each forest patch to serve as a stepping stone for species range shifts. Our results showed that about 94% of the European forested area is expected to experience species range shifts. Our study identified sites of high conservation value for improving and sustaining forest connectivity to facilitate climate-driven range shifts and thus could provide information for climate-smart management of European forests.

Urban sprawl into Natura 2000 network over Europe.

Urban growth is a major threat to biodiversity conservation at the global scale. Its impacts are expected to be especially detrimental when it sprawls into the landscape and reaches sites of high conservation value due to the species and ecosystems they host, such as protected areas. I analyzed the degree of urbanization (i.e., urban cover and growth rate) from 2006 to 2015 in protected sites in the Natura 2000 network, which, according to the Habitats and Birds Directives, harbor species and habitats of high conservation concern in Europe. I used data on the degree of land imperviousness from COPERNICUS to calculate and compare urban covers and growth rates inside and outside Natura 2000. I also analyzed the relationships of urban cover and growth rates with a set of characteristics of Natura sites. Urban cover inside Natura 2000 was 10 times lower than outside (0.4% vs. 4%) throughout the European Union. However, the rates of urban growth were slightly higher inside than outside Natura 2000 (4.8% vs. 3.9%), which indicates an incipient urban sprawl inside the network. In general, Natura sites affected most by urbanization were those surrounded by densely populated areas (i.e., urban clusters) that had a low number of species or habitats of conservation concern, albeit some member states had high urban cover or growth rate or both in protected sites with a large number of species or habitats of high conservation value. Small Natura sites had more urban cover than large sites, but urban growth rates were highest in large Natura sites. Natura 2000 is protected against urbanization to some extent, but there is room for improvement. Member states must enact stricter legal protection and control law enforcement to halt urban sprawl into protected areas under the greatest pressure from urban sprawl (i.e., close to urban clusters). Such actions are particularly needed in Natura sites with high urban cover and growth rates and areas where urbanization is affecting small Natura sites of high conservation value, which are especially vulnerable and concentrated in the Mediterranean region.

Exploring environmental predictors of aquatic macrophytes in water‐dependent Natura 2000 sites of high conservation value: Results from a long‐term study of macrophytes in Greek lakes

Abstract Aquatic macrophytes play a key role in lake dynamics, but human activities and eutrophication have resulted in macrophyte loss in many lakes throughout Europe. In this study, the relationships between aquatic macrophytes and gradients of environmental factors were explored using an extensive set of data collected from 13 lakes of the Greek mainland that are part of the European network Natura 2000. The main objectives were to assess the importance of key abiotic predictors and estimate possible environmental thresholds of macrophyte richness, diversity, and abundance using boosted regression trees (BRTs), as well as to explore further the distribution of dominant macrophyte taxa along environmental gradients. The results reveal conductivity as a significant predictor of macrophyte total cover and diversity. In addition, orthophosphate and nitrate nitrogen appear to play an important role for several macrophyte species and assemblages, reflecting a major effect of eutrophication on the distribution of taxa. The majority of macrophyte assemblages were found in waters characterized by high nutrient content, although their distribution extends along a wide range of phosphorus and nitrogen concentration. In contrast, charophyte species show the optimum of their distribution in clear, oligotrophic waters. This integrated study can be used for ranking environmental factors that influence macrophyte distribution in the lakes of Greece and for identifying taxa or macrophyte assemblages that can be used as effective indicators of changes in the abiotic environment. In addition, the results can contribute to the conservation of freshwater habitats in the protected areas studied. In particular, measures that aim to improve water quality are expected also to restore oligotrophic habitats that are characterized by benthic charophyte vegetation. Overall, the links between macrophyte assemblages and abiotic factors are critically important in improving freshwater biodiversity management and environmental policies in east Mediterranean lakes.

Assessing urban recreation ecosystem services through the use of geocache visitation and preference data: a case-study from an urbanised island environment

Recreation is an important cultural ecosystem service and is one way in which communities experience the direct and indirect benefits arising from the experiential use of their environment. The recent rise in popularity of Global Positioning System (GPS) game applications, which combine information technology with an activity that increases mobility and encourages outdoor enjoyment, provides ecosystem service practitioners with an opportunity to make use of this georeferenced data to assess recreational ecosystem services. Geocaching is one such worldwide outdoor game. It has fixed points of incursion where people can hide and look for caches. This study explores the possibility of using geocaching data as a proxy for recreational ecosystems services in the Maltese Islands. A quantitative analysis of the georeferenced caches was used together with their visit rates and number of favourite points. This was supplemented by two questionnaires that investigated the preferences and experiences of both geocache placers (n=39) and hunters (n=21). Results show that the highest number of caches were placed and searched for in urban areas and that geocaching is strongly associated with the presence and accessibility of urban green infrastructure. The number of geocachers who stated preference for experiences in nature did not translate into high visit rates to sites of high conservation value (protected areas) but landscape value was significantly associated with recreational ecosystem services flow. The results presented here provide evidence that geocaching spatial data can act as an indicator for assessing and mapping recreational ecosystem services in urban environments and in cultural landscapes.

Assessing habitat loss and fragmentation and their effects on population viability of forest specialist birds: Linking biogeographical and population approaches

AbstractAimBiogeographic approaches usually have been developed apart from population ecology, resulting in predictive models without key parameters needed to account for reproductive and behavioural limitations on dispersal. Our aim was to incorporate fully spatially explicit population traits into a classic species distribution model (SDM) using Geographic Information Systems (GIS), aiming at conservation purposes.LocationSouthern South America.MethodsOur analysis incorporates the effects of habitat loss and fragmentation on population viability and therefore provides insights into how much spatially explicit population traits can improve the SDM prediction of habitable habitat. We utilized a well‐studied focal endemic bird of South American temperate rainforests (Scelorchilus rubecula). First, at a large scale, we assessed the historical extent habitat based on climate envelopes in an SDM. Second, we used a land cover change analysis at a regional scale to account for recent habitat loss and fragmentation. Third, we used empirically derived criteria to predict population responses to fragmented forest landscapes to identify actual losses of habitat and population. Then we selected three sites of high conservation value in southern Chile and applied our population model. Finally, we discuss the degree to which spatially explicit population traits can improve the SDM output without intervening in the modelling process itself.ResultsWe found a historical habitat loss of 39.12% and an additional forest cover loss of 3.03% during 2000–2014; the latter occurred with a high degree of fragmentation, reducing the overall estimation of (1) carrying capacity by −82.4%, −33.1% and −45.1% and (2) estimated number of pairs on viable populations by −84.1%, −33.0% and −54.6% on the three selected sites.Main conclusionWe conclude that our approach sharpened the SDM prediction on environmental suitability by 54.4%, adjusting the habitable area by adding population parameters through GIS, and allowing to incorporate other phenomena as fragmentation and habitat loss.

Employing indicators for prioritization of fish assemblage with a view to manage freshwater fish diversity and ecosystem health in the tributaries of Ganges basin, India

The major tributaries of the river Ganges basin are currently threatened by various anthropogenic activities which are hampering the ecosystem stability and fish biodiversity of the basin. Multiple indicators were used to prioritize the fish assemblages in the tributaries and to develop an index that is responsive to human-induced environmental changes. A high percentage of invasive species was described with the orgin index at the most disturbed sites of rivers Gomti and Betwa which also represented a substantial amount of biological disturbance. The Fisheries Assessment Integrity Index based on ecological integrity of different segments of the rivers was used to prioritize different sampling sites of the tributaries. Some of the sampling sites in Gomti and Betwa rivers are reflecting disturbed fish assemblages, a very low Fisheries Assessment Integrity Index score, few threatened species, and a high proportion of invasive species. Principal components analysis of the sampling sites, along with fish assemblage, reflected the influence of the habitat parameters on structuring the assemblage pattern. This study identified depth, flow, water quality and land uses in shaping fish assemblages. The combination of various indices in this study should provide more accurate measures in identifying sites of high conservation value.

Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data.

Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in recent decades and may not capture actual species occurrence well because the distributions of species, especially at the edges of their range, are typically dynamic and may respond strongly to short-term climate variability. Our goal here was to test whether bird occurrence models can be predicted by either covariates based on short-term climate variability or on long-term climate averages. We parameterized species distribution models (SDMs) based on either short-term variability or long-term average climate covariates for 320 bird species in the conterminous USA and tested whether any life-history trait-based guilds were particularly sensitive to short-term conditions. Models including short-term climate variability performed well based on their cross-validated area-under-the-curve AUC score (0.85), as did models based on long-term climate averages (0.84). Similarly, both models performed well compared to independent presence/absence data from the North American Breeding Bird Survey (independent AUC of 0.89 and 0.90, respectively). However, models based on short-term variability covariates more accurately classified true absences for most species (73% of true absences classified within the lowest quarter of environmental suitability vs. 68%). In addition, they have the advantage that they can reveal the dynamic relationship between species and their environment because they capture the spatial fluctuations of species potential breeding distributions. With this information, we can identify which species and guilds are sensitive to climate variability, identify sites of high conservation value where climate variability is low, and assess how species' potential distributions may have already shifted due recent climate change. However, long-term climate averages require less data and processing time and may be more readily available for some areas of interest. Where data on short-term climate variability are not available, long-term climate information is a sufficient predictor of species distributions in many cases. However, short-term climate variability data may provide information not captured with long-term climate data for use in SDMs.

Climate change will increase the potential conflict between skiing and high‐elevation bird species in the Alps

AbstractAimTo assess the extent of the possible future conflict between skiing and biodiversity driven by climate change, human adaptation and species' distribution shifts.LocationItalian Alps.MethodsWe assessed the extent of the possible future conflict between skiing and biodiversity by predicting locations likely to be suitable for both skiing and for high‐elevation birds in the Italian Alps by modelling ski‐piste and species presence in relation to climate, topography and habitat. Potential conflict was assessed by comparing the overlap of areas projected as suitable for skiing and those suitable for four high‐elevation bird species under different scenarios of climate change for the year 2050.ResultsAreas suitable for both ski‐pistes and birds were projected to contract towards upper elevations, which for birds resulted in an average decrease of 58–67% of suitable area. The degree of overlap between species and skiing was projected to increase, especially for the most valuable sites, that is, those hosting the most species, or the most threatened species.Main conclusionsGiven the alarming range contractions forecast for high‐elevation species, and the potential impact of ski‐pistes on those species, it is essential to safeguard high‐mountain grasslands against negative effects of ski development. An effective conservation strategy at a landscape scale needs to consider prevention of ski‐piste construction in sites of high conservation value. The approach developed here provides a means by which such a strategy could be formulated, and which could be potentially applied elsewhere to investigate the effect of human adaptation on biodiversity.

Simple tools for the evaluation of protected areas for the conservation of grasshoppers

Spatial conservation prioritization needs a strong informational background on the conservation value of sites. However, standard diversity indices do not distinguish between less valuable (e.g. invasive species) and highly valuable species (e.g. threatened endemics). Furthermore, park managers often lack the taxonomic capacity to study species-rich insect groups. Therefore, there is a need for indices that consider the conservation value of species and simple indicators for the conservation value of sites. The aim of our study was to develop such indices and test them in a biodiversity hotspot. We studied grasshopper diversity in the UNESCO World Heritage “Cape Floral Region Protected Areas” (South Africa). We used endemism, mobility and rarity to calculate a grasshopper conservation index (GCI) for each species and site and a standardized index (GCIn) to evaluate the mean conservation value of species per site. We analyzed the indicator value (IndVal) of environmental factors for identifying sites of high conservation value or high biodiversity. Unlike plant species richness, we found the highest species richness in the Eastern Cape. The main factors determining grasshopper diversity were vegetation heterogeneity, altitude and cover of bare ground. The abundance of wingless grasshopper species and the ratio of wingless to winged species were suitable indicators of conservation value (regarding the diversity of rare or endemic species) of sites. These factors might function as conservation indicators in other regions as well, as they are generally associated with the occurrence of endemic species. GCI/GCIn are globally applicable tools for the evaluation of grasshopper communities.

Implications of afforestation for bird communities: the importance of preceding land-use type

Afforestation of open habitats is one of the principal land-use changes underway in Europe and elsewhere in the world at present, and it can have a considerable impact on local biodiversity. The sustainable expansion of global forest plantations requires an understanding of the factors that determine the ecological impacts of afforestation. This study set out to determine the importance of preceding land-use type in determining the outcomes of afforestation for bird communities. Paired comparisons of 5-year-old exotic conifer plantations and matching non-forested sites were studied in areas of low (peatland), intermediate (wet grassland) and high (improved grassland) management intensity. Afforestation resulted in an overall increase in total bird density in all three habitat types. The effects of forest planting on bird conservation were found to be positively related to prior management intensity at the site. The density of bird species of conservation concern increased in response to the planting of intensively managed grassland sites, but decreased in response to afforestation of peatlands and of grasslands under intermediate management intensity. This study shows that plantation forests can, in some contexts, offer opportunities for bird conservation, and the findings highlight the trade-offs that are an integral part of land-use change. Therefore, where afforestation planning includes consideration of its impact on bird communities, planting should take place predominantly on sites of low biodiversity value, such as agriculturally improved grasslands. Furthermore, the preservation of sites of high conservation value within areas of afforestation would confer advantages on bird communities.

Initial assessment of coastal benthic communities in the Marine Parks at Robinson Crusoe Island

The National Biodiversity Strategy developed in Chile aims to protect 10% of the surface area of the most relevant marine ecosystems. The waters around the Juan Fernandez Archipelago were not protected until 2014, when a Multiple Use Marine Protected Area was created in the 12 nautical miles around the archipelago, which includes five marine parks in sites of high conservation value. Three of these parks are located around Robinson Crusoe Island. This study aims to define a baseline for monitoring the impact of the marine protected area and provides ecological information to improve the understanding of coastal marine ecosystems around Robinson Crusoe Island. In addition to a characterization of bathymetry and habitats, intertidal and subtidal communities were sampled using transects and quadrats within the marine parks. We quantified species richness and abundances, which were later organized into functional groups for algae and trophic groups for mobile organisms. Although species richness did not vary between sites nor among the habitats sampled, we observed important differences in species abundance and composition as well as in functional and trophic groups both between sites and habitats. Among our results, we highlight: a) the dominance of endemic algae in intertidal and subtidal (mainly corticated and corticated foliose) habitats, b) high abundances of macroinvertebrate herbivores in intertidal habitats and detrivores in subtidal habitats, c) dominance of invertivorous fish in the subtidal, which are the primary predators of mobile benthic organisms. This characterization includes both the inter and subtidal coastal communities of the Juan Fernandez Archipelago.

Impacts of culling and exclusion of browsers on vegetation recovery across New Zealand forests

Introduced browsing animals negatively impact New Zealand’s indigenous ecosystems. Eradicating introduced browsers is currently unfeasible at large scales, but culling since the 1960s has successfully reduced populations to a fraction of their earlier sizes. Here we ask whether culling of ungulates has allowed populations of woody plant species to recover across New Zealand forests. Using 73 pairs of permanent fenced exclosure and unfenced control plots, we found rapid increases in sapling densities within exclosures located in disturbed forests, particularly if a seedling bank was already present. Recovery was slower in thinning stands and hampered by dense fern cover. We inferred ungulate diet preference from species recovery rates inside exclosures to test whether culling increased abundance of preferred species across a national network of 574 unfenced permanent forest plots. Across this network, saplings were observed irrespective of their preference to ungulates in the 1970s, but preferred species were rarer within disturbed sites in the 1990s after long-term culling and despite nationwide increases in sapling densities. This indicates that preferred species are relatively heavily affected by browsing after culling, presumably because remaining animals will increase consumption of preferred species as competition is reduced. Our results clearly suggest that culling will not return preferred plants to the landscape immediately, even given suitable conditions for regeneration. Complete removal of ungulates rather than simply reducing their densities may be required for recovery in heavily browsed temperate forests, but since this is only feasible at small spatial scales, management efforts must target sites of high conservation value.

Saproxylic beetles as indicator species for dead-wood amount and temperature in European beech forests

Beech forests in Central Europe are under strong anthropogenic pressure. Yet they play a fundamental role for biodiversity and are therefore increasingly considered in conservation activities. Sites of high conservation value can be efficiently defined by the use of indicator species, but very few studies have identified indicator species for beech forests on a continental scale. Here we determined the efficacy of saproxylic beetles as indicator species for European beech forests and studied the effect of the amount of dead wood and temperature on their presence. We analyzed data from 988 trap catches from 209 sites in 7 European countries. Using the flexible indicator approach, which allowed combinations of two temperature groups (warm and cool) and three dead-wood amount categories (small, intermediate, high) to be considered, we identified 127 indicator species. Generally, we found more indicator species of beetles at warmer sites and at sites with larger amounts of dead wood. Indicator species at cooler sites were found only in combination with larger amounts of dead wood. We present a comprehensive, data-based list of indicator species of saproxylic beetle for near-natural beech forests, as required in the framework of the European Natura-2000 concept for habitat evaluation. We identified the conspicuous Lucanidae as the family with the highest percentage of indicator species and thus recommend it as a priority indicator group for monitoring. Our results furthermore provide evidence that large amounts of dead wood are particularly important in cool, montane beech forests for maintaining high diversity.

Colonization of Pinus halepensis in Mediterranean habitats: consequences of afforestation, grazing and fire

The expansion of P. halepensis from plantations into natural sites of high conservation value is becoming a frequent occurrence across the Mediterranean zone of Israel. We studied how colonization of Pinus halepensis in natural Mediterranean habitats is related to afforestation, cattle grazing and fire. The study was conducted in a Mediterranean garrigue (Shrubland) located in Ramat Hanadiv Nature Park, southern Mt. Carmel region, Israel. The study area (ca. 350 ha) was divided into cells (100 × 100 m) each of which was categorized with respect to distance from planted pines, grazing (grazed since 1990/ungrazed), fire (burned in 1980/unburned), and vegetation structure (garrigue, dense garrigue, dense woodland). The location of colonizing pines, typically three m or more in height, was determined using an aerial photograph. Density of colonizing pines decreased linearly with the distance from planted pines within 300 m from planted pines with a long tail that extended out to ca 1,000 m. Over 90% of the colonizing pines that were found were located within a distance of 300 m (56% of the park area) from planted pines. Colonization was about two times greater under grazing than without grazing. The effects of fire and of the interaction fire × grazing were found insignificant. A separate analysis reveled that colonization was about 2 times larger in patches of sparse woody cover than in those of dense cover. In conclusion, pine colonization was mainly determined by the proximity to seed sources. Additionally, pine colonization was enhanced by cattle grazing probably through reduction of the natural vegetation cover.

Determining the important environmental variables controlling plant species community composition in mesotrophic grasslands in Great Britain

AbstractQuestion: What is the relative importance of local site effects and selected important environmental variables in determining plant species composition? How do species respond to these environmental variables?Location: Ten mesotrophic grassland sites of high conservation value in southern England.Methods: Species cover was assessed in between 10 and 25 randomly selected 1‐m2 quadrats at each site. At each quadrat degree of waterlogging (W), soil Olsen extractable phosphorus (P) and soil pH were measured. Variation partitioning was used to separate site and soil effects, and HOF (Huisman, Olff & Fresco) modelling was used to produce response curves for the major species on soil gradients, based on coenoclines derived from partial canonical correspondence analysis (pCCA).Results: Variation partitioning identified Site as the most important environmental variable (34.6%). Only 18.7% was accounted for by the three soil variables together; W (degree of waterlogging), P and pH accounted for 11.1%, 5.7% and 4.3%, respectively in raw form with 2.4% shared. However, when Site and the other soil variables were removed the variation explained reduced to 2.3% for W, 1.1% for P and 1.0% for pH. The species responses to each of these soil environmental factors could be separated into four types on each gradient. Most species were abundant at low W, low soil P and intermediate pH.Conclusions: Site‐based factors were more important than the three soil variables, which were assumed to be directly or indirectly associated with productivity. This implies that each site has unique properties that are more important than the soil variables. The three soil factors were, however, significant and the groups of the most common species, based on significant response curves, can be used as a first approximation of indicators of environmental conditions in British mesotrophic grasslands for conservation. However, W accounted for most variation, and the current reliance on soil available P and soil pH for assessing conservation/restoration potential should be viewed with caution.

Impact threshold for an alien plant invader, Lantana camara L., on native plant communities

Alien plant invaders significantly threaten native community diversity, although it is poorly understood whether invasion initiates a linear or non-linear loss of resident species. Where low abundances of an invader have little impact on native species diversity, then a threshold level may exist, above which native communities rapidly decline. Our aim was to assess the broadscale effects of an alien thicket-forming shrub, lantana ( Lantana camara L.), on wet sclerophyll forest in southeastern Australia. Vascular plant species richness, abundance and composition were measured and compared along a gradient of lantana invasion. There was a strong negative non-linear relationship between native species richness and lantana cover, indicative of an impact threshold. Native species richness remained stable below 75% lantana cover, but declined rapidly above this threshold level, leading to compositional change. Thus, sparse lantana infestations had evidently little effect on the resident community, with impacts elicited at an advanced stage of invasion. The impact of lantana was pervasive, with all major structural groups (i.e. ferns, herbs, shrubs, trees and vines) exhibiting significant species losses; however, the rate of species loss was relatively greater for tree and shrub species, signalling a shift in vegetation structure from tall open forest to low, dense lantana-dominated shrubland. Potentially, broadscale conservation of species diversity could be achieved by maintaining lantana infestations below the 75% cover impact threshold at sites containing regionally common species that are also widely represented in non-invaded vegetation. This would enable targeted invader eradication at sites of high conservation value (i.e. those containing regionally rare species or endangered ecological communities).

An indicator system for identification of sites of high conservation value for saproxylic oak (Quercus spp.) beetles in southern Sweden

The saproxylic beetle fauna on old oaks was sampled in four regions of southern Sweden using two methods: window and pitfall trapping. The aim was to test a way of finding indicator species which can be used to identify sites with high species number or that scored high on a conservation priority species index, based on occurrence of red-listed species. From 92 sites surveyed, in total 164 species of saproxylic beetles were identified. Different sets of indicator species were selected based upon 22 sites from a centrally located region. Predictions of species number and the index for 30 other sites from the same province were made. The correlation between observed and predicted species number and the index increased with increasing number of indicators. When comparing different treatment of species indata, the explanatory power of predictions was strongest for presence/absence data. Indicator sets of species effectively caught with pitfall traps gave overall the best predictions of both species number and the index. Predictions of species number and the index worked well within the same regions but gave varied result for the three other regions which shows that transferability of indicators between regions may be doubtful.

PROXIMITY TO FORESTS DRIVES BIRD CONSERVATION VALUE OF COFFEE PLANTATIONS: IMPLICATIONS FOR CERTIFICATION

Widespread loss of primary habitat in the tropics has led to increased interest in production landscapes for biodiversity conservation. In the Western Ghats biodiversity hotspot in India, shade coffee plantations are located in close proximity to sites of high conservation value: protected and unprotected forests. Coffee is grown here under a tree canopy that may be dominated by native tree species or by nonnative species, particularly silver oak (Grevillea robusta). We investigated the influence of properties at the local scale and the landscape scale in determining bird communities in coffee plantations, with particular emphasis on species of conservation priority. We used systematic point counts in 11 coffee plantation sites and analyzed data in a randomized linear modeling framework that addressed spatial autocorrelation. Greater proportion of silver oak at the local scale and distance to contiguous forests at the landscape scale were implicated as factors most strongly driving declines in bird species richness and abundance, while increased basal area of native tree species, a local-scale variable, was frequently related to increased bird species richness and abundance. The influence of local-scale variables increased at greater distances from the forest. Distance to forests emerged as the strongest predictor of declines in restricted-range species, with 92% reduction in the abundance of two commonly encountered restricted-range species (Pompadour Green Pigeon and Yellow-browed Bulbul) and a 43% reduction in richness of bird species restricted to Indian hill forests within 8 km of forests. Increase in proportion of silver oak from 33% to 55% was associated with 91% reduction in the abundance of one commonly encountered restricted-range species (Crimson-fronted Barbet). One conservation strategy is providing incentives to grow coffee in a biodiversity-friendly manner. One implication of our study is that plantations located at varying distances to the forest cannot be compared fairly for biodiversity friendliness by existing certification methodology. Another is that conservation of existing forests at the landscape scale is essential for maintaining higher biodiversity in coffee plantations. Incentive schemes that promote conservation of remnant forests at the landscape scale and biodiversity-friendly practices locally and that relate to coffee communities as a whole rather than individual planters are likely to be more effective.