Habitat Evaluation Research Articles

Detection of crayfish plague spores in large freshwater systems

Summary Indigenous European freshwater crayfish (ICS) are threatened due to invasive North American freshwater crayfish that are natural carriers of Aphanomyces astaci which causes crayfish plague. Infectious A. astaci zoospores are released from carrier crayfish, but little is known about the spore abundance in water systems that either host non‐indigenous crayfish species (NICS) or experience crayfish plague outbreaks. We tested two large‐scale filtering approaches to generate new insight about the abundance and dynamics of A. astaci spores in natural freshwater systems. Depth filtration (DF) and dead‐end ultrafiltration (DEUF) followed by A. astaci‐specific quantitative real‐time PCR was used to monitor A. astaci spores in large Nordic lakes hosting A. astaci‐positive Pacifastacus leniusculus, the dominating NICS in Northern Europe. Crayfish and water were sampled together to compare the A. astaci pathogen load in tissues, A. astaci prevalence in the population and the corresponding spore density in water. Samples were also obtained from a river where indigenous noble crayfish suffered from acute crayfish plague. The sensitivity of the filtering techniques was evaluated using simulation of random events. We detected A. astaci spores in lakes hosting NICS with both filtering methods but predominantly at concentrations below c. 1 spore L−1. We found a significant positive association between A. astaci spore density in water, the A. astaci prevalence in the corresponding NICS population and the tissue pathogen load. Water from the river with the ongoing crayfish plague outbreak contained overall c. 43 times more spores L−1 than water hosting NICS. Both filtering techniques proved suitable and equally sensitive, but simulations suggest that an optimization of the spore recovery could yield a 10‐fold increase in the DEUF‐method sensitivity. Synthesis and application. Our study demonstrates a low amount of pathogen spores are present in aquatic environments with non‐indigenous crayfish species, emphasizing the need for large‐volume filtering techniques for successful detection. The approach can be used for risk assessments and to improve conservation and management strategies of crayfish in Europe. Applications of this method include targeted disease surveillance, habitat evaluation prior to crayfish re‐stockings and water monitoring that can minimize disease transmission and spread, for example in crayfish farms and prior to fish movements for stocking purposes.

Applying Factor Analyses of Statistics to Evaluate Habitat Biodiversity Index in Dry‐Season Creeks

The purpose of this study is to analyze the habitat factors (environmental variables) affecting dry-season creek fish, and evaluate habitat biodiversity index (HBI) in dry-season creeks. This research determined HBI formula by 133 study sites in the creek flows in seven rivers in Taiwan from 2007 to 2008. This research considered 10 habitat factors: water depth, width, length, pH, electrical conductivity, temperature, current velocity, rainfall, elevation, and substrate diversity. Using the principal component analysis (PCA), varimax rotated factor analysis (FA), and the simultaneous regression in product-exponential model (PEM), fish total numbers and HBI were formulated by these 10 habitat factors. Pearson's correlation coefficient matrix and three-factor loading plots reported that current flow velocity, rainfall, and elevation affected on fish numbers similarly; besides, water length (logarithmic) and width (logarithmic) had the positive and similar influences in fish numbers. Habitat evaluation levels were classified six groups, namely, excellent habitat, very good habitat, good habitat, fair habitat, poor habitat, and then very poor habitat. In brief, HBI was reasonable and calculated simply by 10 environmental variables of fish habitats. The results of this study can be applied extensively to evaluate the conditions of fish habitats in dry-season creeks for habitat recovery projects.

Position choice by red-spotted masu salmon: applicability of a bioenergetics model to habitat evaluation of headwater streams in southwestern Japan

Habitat loss and degradation due to human activities are major threats to stream fishes. To predict and/or monitor habitat changes, quantification of suitable habitats for target fish species is indispensable. For drift-feeding salmonids, bioenergetics models that estimate energetic benefit (net energy intake: NEI) can be used for their habitat evaluation. In this study, we examined applicability of a bioenergetics model, which had been developed for Arctic grayling (Thymallus arcticus) in Alaska, North America, to habitat evaluation for red-spotted masu salmon (Oncorhynchus masou ishikawae) in southwestern Japan, by assessing whether their position choice can be predicted by the model. The results showed that the model successfully predicted their position choice in 12 of the total 16 study sections. Further, in two sections inhabited by several individuals, strong positive correlations were found between NEI potential and fish body length, being consistent with a widely reported trend in drift-feeding salmonids that larger individuals occupy more profitable positions. We concluded that the bioenergetics model we tested is useful in evaluating habitat quality for red-spotted masu salmon. Our results suggested that NEI models can be regarded as a site-independent, widely applicable tool for habitat evaluation for drift-feeding salmonids.

Biodiversity of Cetoniinae beetles (Coleoptera: Scarabaeidae) in introduced and native habitats in the Brazilian Atlantic Forest

AbstractThe ecology of the beetles of the subfamily Cetoniinae (Coleoptera: Scarabaeidae) is relatively poorly known worldwide. In the neotropics in particular, there are far less studies than in other biogeographic regions. In part due to this lack of knowledge, cetoniines are not considered indicators of habitat quality in the Neotropical region. In this study, we compare the abundance, diversity, and species composition of cetoniines in three different habitats in Brazil: two exotic (Brachiaria pasturelands and eucalyptus plantation) and one native (Brazilian Atlantic Forest). We also provide diagnostic images of both sexes and of the genitalia of males of all species to facilitate species identification in further studies. The beetles were collected weekly from September to December 2012 with traps baited with fermented fruit, in five eucalyptus plantations (Eucalyptus grandis Hill ex Maiden), five exotic pasturelands (Brachiaria spp.), and five patches of Brazilian Atlantic Forest. The abundance and diversity of cetoniines was found to be lower in the eucalyptus plantations and about the same in the forest and pasturelands. The low diversity found and the little information available on the ecology of Neotropical Cetoniinae is insufficient to propose these beetles as candidates for the habitat evaluation in Brazil.

Ichthyofaunal assessment of the Gelami and Tinggi Rivers, Pahang River System, eastern Malay Peninsula, following construction of an adjacent building complex

The fluvial fish fauna of the Gelami and Tinggi Rivers, before and after the construction of a building complex in the adjacent forest, was compared on the basis of a literature survey (covering the period: 1997–2003) and a field survey in 2010. Forty fish species, representing 14 families and 5 orders, were recorded in total, the field survey including new records for Barbonymus gonionotus, Glyptothorax laosensis and Macrognathus maculatus. On the other hand, twelve species, including Osteochilus microcephalus, Luciosoma setigerum, Cyclocheilichthys apogon, Tor tambroides, Acantopsis choirorhynchos, Homaloptera orthogoniata, Clarias teijsmanni, Clarias macrocephalus, Pseudomystus leiacanthus, Mystus nigriceps, Parambassis siamensis and Trichopodus trichopterus, that had been listed previously, were not recorded by the latter. An analysis of the results using McNemar’s chi-squared test indicated that the fish fauna of the rivers has changed significantly following the construction, continuous quantitative monitoring and habitat evaluation being necessary for conservation of future biodiversity levels.

횡성댐 상·하류의 어류군집 구조와 최적 생태유량 산정

In this study, a comprehensive field monitoring was conducted to understand habitat conditions of fish species in up and downstream of Hoengseong Dam. Based on the monitoring data, riverine health conditions such as composition ratio of fish species, bio-diversity (dominance index, diversity, evenness and richness), index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) were assessed, and optimal ecological flowrates (OEF) were estimated using the habitat suitability indexes (HSI) established for three fish species Coreoleuciscus splendidus, Pungtungia herzi and Microphysogobio longidorsalis selected as icon species using the physical habitat simulation system (PHABSIM). The total number of species sampled was 20 species, and two species of Zacco platypus (30.4%) and C. splendidus (20.9%) dominated the fish community. As a result, it was revealed that IBI and QHEI values decreased from upstream to downstream along the river. The estimated IBI value ranged from 24 to 36 with average being 30.9 out of 50, rendering the site ecologically fair to good health conditions. HSI for C. splendidus were determined according to three different month in terms of season: Spring (April), Summer (August) and Autumn (October). HSI for flow velocity were estimated at 0.7 to 0.8 m/s for the Spring, 0.5 to 1.0 m/s for the Summer and 0.8 to 0.9 m/s for the Autumn. HSI for water depth were estimated at 0.3 to 0.5 m for the Spring; 0.3 to 0.5 m for the Summer; and 0.3 to 0.4 m for the Autumn. OEF was estimated at 4.2 and 6.5 m 3 /s for the Spring and Autumn, and 12.0 m 3 /s for the Summer. Overall, it was concluded that the Hoengseong Dam has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

EVALUATION OF WILDLIFE HABITATS IN THE VICTORIA· RANDENIGALA·RANTAMBE SANCTUARY USING LlFE·FORM AND HABITAT MODELS

A suitable hahilal evaluation method is an important 1001 for wildlife managers 10manipulate wildlife diversity, to predict how proposed hahital changes will effect differentwildlife communities. as well as 10 determine the quantity and quality of available habitatsfor a particular species. A simple method of habitat evaluation is the use or life-form andhabitat models (Anderson & Gutzwiller. 1994). During this process, all species of animalsfound in it given area arc placed in distinct life-form categories, based on theirpredominant habitat use paucrns for feeding and reproduction, Once the life-form table ismade. more detailed data on habiln! use is presented in hahitat tables for individual speciesunder each Iifc-Ionn category. By adding the number of habitats used by each species forreproduction and breeding, versatility score (V) can be obtained, Species with a highversatility score arc the least sensitive to habitat manipulation. This would also enablewildlife managers to examine the impact of habitat loss/modification and Ii~;t the speciesaffected. This method was applied to evaluate the native vertebrates and their habitats inthe VRR sanctuary, A total of 252 native vertebrates recorded were placed under 22distinct life-form categories. These species were further assessed according to their majorhabitat utilisation pancrns. Six major aquatic habitats and nine major terrestrial habitatswere identified, Based on the versatility score of each species, they were grouped into threesensitivity categories for hahitat manipulation: most sensitive. moderately sensitive andleast sensitive. The most widely used habitat of fauna were recogniscd, based on the lifeforms and habitat models. This simple method could he adopted to evaluate the faunalhabitats in all protected areas of Sri Lanka.

Ecological Health Assessments of an Urban Lotic Ecosystem Using a Multimetric Model along with Physical Habitat and Chemical Water Quality Assessments

The objective of this study was to diagnose integrative ecological health of an urban stream,which is located in the Asian temperate region. The research approach was primarily based on the Index ofBiological Integrity (IBI) using fish assemblage and a Qualitative Habitat Evaluation Index (QHEI). And these indexes were compared with long-term conventional chemical dataset during 1996-2005. For the experiment, four sampling sites were chosen from the stream and wading method was used for fish collection during 2004-2005. We developed a stream health assessment model (SHA model) for the regional application. Stream health conditions, based on the SHA model, averaged 23 indicating a fair-poor condition, and varied from 18 to 40 depending on the sampling stations. Values of QHEI varied from 55 (fair-poor condition) to 112 (good-fair condition) and the values were significantly lower in the down stream than the headwater. Water quality, based on COD, BOD, TN and TP declined from the upstream to downstream reach. The proportion of sensitive species showed a negative linear function with BOD and the tolerant was vise versa. Values of SHA model reflected the chemical and physical habitat conditions and this result was clearly evident in the downstream reach. These outcomes were supported byprincipal component analysis (PCA) of IBI vs. other factors. Overall these results suggest that the impacts to the health of this stream are due to the combined effects of both chemical and habitat degradation.

English

The study explored the habitat structure of flat-headed cusimanse (Crossarchus platycephalus) in Federal University of Technology, Akure (FUTA) Wildlife Park, Ondo State. It was undertaken during both wet and dry seasons of the year 2012. In assessing the habitat, ten plots (10 x 10 m2 each) were marked out of the total land area of the Park. A total of fifteen (15) different species were identified with diameter at breast height values ranging from 4 to 130 cm. The frequency of tree species contained in the plots revealedFuntumia elastica to be of the highest frequency. Elaeis guineensis emerged as the highest dominating woody plant. The habitat evaluation revealed that, the species of the flat-headed cusimanse are adapted to fairly dense vegetation and preferred to utilize fallen logs, thicket of bush, environments with considerable wetness with pond or stream and crevices formed by fallen logs and rock outcrops as habitats. The study has given a base line information on where flat-headed cusimanses are likely to be seen, places and features they utilize as habitat in order to ensure easier ecological studies on them and to see these features not as useless and nuisance especially the fallen, dead logs, the thickets and the crevices, but as principal components of some animal’s habitat.   Key words: Crevice, dominance, diversity, dwarf mongoose, requirements, patrol.  

Habitat evaluation and population viability analysis of the last population of cao vit gibbon (Nomascus nasutus): Implications for conservation

The cao vit gibbon (Nomascus nasutus) is among the most endangered primates in the world. The only surviving population lives in a karst forest patch along the China–Vietnam border. In this study, we used high-resolution satellite images to evaluate the habitat quality of the gibbon in the area immediately surrounding the last population and predict the potential gibbon habitat. We then used Vortex to simulate population responses to changes in the habitat’s carrying capacity. Our results showed the gibbon population is approaching the carrying capacity of their current habitat, and carrying capacity has a significant impact on population changes. Two potential habitats were located in a forest connected to the current habitat by a narrow forest corridor, situated above an underground river. Based on the results, we recommend: (1) prohibiting agriculture and grazing activities within the current gibbon habitat; (2) expanding the Cao Vit Gibbon Conservation Area in order to protect potential cao vit habitats in Vietnam; (3) protecting forest corridor that connect the current cao vit habitat to potential habitats; and (4) rehabilitating the forests currently depauperate of important food species in order to support the expansion of both the gibbon population and the range. This research both provides important insight into sustaining the current gibbon population as well as suggestions for both Vietnamese and Chinese local governments planning habitat restoration at the study site.

Ecosystem Health Diagnosis Using Integrative Multiple Eco-metric Model Approaches

The object of this study was to evaluate lotic ecosystem health using multiple eco-metric approaches such as water chemistry diagnosis, physical habitat health evaluations, and biological integrity modeling at 100 streams of four major watersheds. For the study, eight chemical water quality parameters such as nutrients (N, P) and organic material were measured and 11-metric models of Qualitative Habitat Evaluation Index (QHEI) and multiple eco-metric health assessment model (MEHA) were applied to the four major watershed. Nutrient analysis of nitrogen (N) and phosphorus (P) in all watersheds indicated a eutrophic state depending on the locations of sampling streams. Physical habitat health, based on the QHEI model, averaged 114 (range: 56 - 194), judging as a good condition by the criteria of Plafkin et al. (1989). In addition, primary (H1 - H4), secondary (H5 - H7), and tertiary habitat metric variables (H8 - H11) were analyzed in relation to the physical habitat degradations. The plots of tolerant species (PTS) and sensitive species (PSS) to water quality showed that the proportions of PTS had positive linear functions with nutrients, and that the PSS had inverse linear relations with the chemical variables. The model of eco-metric health assessment showed that mean MEHA was 20.4, indicating a fair condition. Overall, our data suggest that water chemistry, based on nutrients and organic matter, directly modified the trophic structures in relation to food chain in the aquatic ecosystems, and then these directly influenced the compositions of tolerance/sensitive species, resulting in degradations of overall ecological health.

Landscape-scale impacts of transportation infrastructure on spatial dynamics of two vulnerable ungulate species in Ghamishloo Wildlife Refuge, Iran

Development of roads through protected areas can have deleterious effects on natural habitats containing species of conservation concern. During the past decades road construction has affected many former remote areas and led to fragmentation and isolation of wildlife populations. The present study focuses on the ecological impacts of Isfahan's West Freeway, which passes through Ghamishloo Wildlife Refuge; an IUCN category IV protected area, in Isfahan Province. The two key affected species, both classified as vulnerable by IUCN, the goitered gazelle (Gazella subgutturosa subgutturosa) and the wild sheep (Ovis orientalis isphahanica) were subject to impact analyses. We used habitat evaluation procedure (HEP) as a habitat-based impact assessment methodology which considers habitat quality and quantity. Habitat quality was measured as habitat suitability index (HSI) for each species. By literature review and field observations, five variables defining habitat suitability were identified and suitability maps for both species generated. Habitat units (HUs) were derived from multiplying the HSI for each species by the habitat area before and after freeway construction. The results showed that due to the construction of the freeway, about 14% of the HUs for goitered gazelle and about 9% of the HUs for wild sheep were lost. In addition, for quantifying landscape pattern change due to freeway construction, various landscape metrics were calculated for the species distribution polygons for two times before and after freeway construction. Results obtained through quantifying landscape metrics showed that mean nearest neighbor (MNN) and number of patches (NP) metrics increased. On the other hand, CONTAG metric decreased in both goitered gazelle and wild sheep distribution polygons, demonstrating the negative effect of freeway on these species distribution polygons integrity. According to the results of this study, mitigation and compensation activities should be considered in Ghamishloo Wildlife Refuge. Our study demonstrated that HEP method combined with quantifying landscape metrics might provide a powerful tool for assessing ecological impact of technical infrastructures on populations of far-ranging species of conservation concern.

基于MAXENT模型的贺兰山岩羊生境适宜性评价

Habitat evaluation has an important significance for management of wildlife populations and conservation planning. Geographic Information Systems( GIS) and abundant landscape-level data provide new opportunities for biologists to evaluate wildlife habitat quality. Maximum Entropy( MAXENT) is a recently introduced modeling technique,achieving high predictive accuracy and enjoying several additional attractive properties. With the purpose of predicting habitat for blue sheep( Pseudois nayaur) in the Helan Mountain Range,we collected the occurrence records for this species and the environmental factors,the occurrence records were collected from the study area from 2010 to 2011,and the date of environmental factors were extracted from the Thematic Mapper( TM) image of Helan Mountain in 2007. The method relies on the combined use of GIS and Maximum Entropy( MAXENT) model in this research. GIS was used to produce the data needed in the model,MAXENT can model species geographic distributions with presence-only data,and is suitable for the research because absence data are not available for blue sheep. A map indicated the distribution of habitat suitability of blue sheep in Helan Mountain generated from the data and software. In this paper,the method of Receiver Operating Characteristic( ROC) curve analysis was used to assess the accuracy of MAXENT model,the area under ROC curve( AUC) of the model was 0. 915,indicating that the result of assessment was excellent,and the results showed the relationships between the distribution of blue sheep and the environmental factors,the result of Jackknife test indicated that the mining,slope,altitude and road were the main factors influencing habitat selection of blue sheep. Along with the increase of slope,distance from mine and road,the habitat suitability increased gradually,and habitat suitability decreased gradually with the increasing distance from water. Suitable habitat was mainly distributed in southwest of Ningxia Helan Mountain National Nature Reserve( east part) and lesser distributed in the Inner-Mongolia Helan Mountain National Nature Reserve( west part),with the total area of 1 006. 9km2,accounting for 28% of the total assessment area. Blue sheep preferred to use montane savanna dominated and the rugged slopes at elevations of 1 500—2 300 m. There were two factors interfered in achieving accurate results,one was difficult to reach occurrence points for the steep terrain,and the other was that we could not get the information of traffic flow on every road. During the research,we reduced the error by recording the nearest position to the target point and choosing the main road on the maps. The results showed that the most serious human interferences were mining and road,more regulatory actions are needed to be taken in those aspects to improve the habitat's quality as well as promote the progress of the population.

Assessment of Habitats according to Groyne Types (Using Pale Chub)

A groyne zone formed by installing groynes functions as habitat or shelter for aquatic organisms during a flood. Since flow characteristics over a groyne zone are affected directly by groynes, understanding flow patterns due to shapes and types of groynes is of importance for designing groynes. In order to use groynes as an eco-friendly river structure, the ecological effects should also be considered at the design stage. In Korea, the ecological effects of groynes have rarely been examined or included for the actual design. In this study, a set of experiments were carried out to investigate flow pattern changes depending on different types of groynes. Based on the flow characteristics in the groyne zone, the scales of habitats and shelters by the groyne types were estimated. In addition, to test the applicability of a habitat evaluation model to the ecological design of groynes, River2D was used for a virtual river. For assessment of the groyne’s function of ecological habitat, the suitability index of a habitat for pale chub, one of the popular fishes in Korea, was used and the habitat areas by the groyne types were analyzed. The flow changes depending on the groyne types simulated by River2D show the applicability for the simulation of an ecological habitat to the groyne design.

Multi-level stressor analysis from the DNA/biochemical level to community levels in an urban stream and integrative health response (IHR) assessments

The objectives of this study were to identify multi-level stressors at the DNA/biochemical level to the community level in fish in an urban stream and to develop an integrative health response (IHR) model for ecological health diagnosis. A pristine control site (S c ) and an impacted site (S i ) were selected from among seven pre-screened sites studied over seven years. Various chemical analyses indicated that nutrient enrichment (Nitrogen, Phosphorus) and organic pollution were significantly greater (t > 8.783, p < 0.01) at the S i site compared to the S c site. Single-cell gel electrophoresis (comet assays) of DNA-level impairment indicated significantly (t = 5.678, p < 0.01) greater tail intensity, expressed as % tail-DNA, at the S i site and genotoxic responses were detected in the downstream reach. Ethoxyresorufin-O-deethylase (EROD) assays, as a physiological bioindicator, were 2.8-fold higher (p < 0.05, NK-test after ANOVA) at the S i site. Tissue analysis using a necropsy-based health assessment index (NHAI) showed distinct internal organ disorders in three tissues, i.e., liver, kidney, and gill, at the S i site. Population-level analysis using the sentinel species Zacco platypus showed that the regression coefficient (b) was 3.012 for the S i site and 2.915 for the S c site, indicating population skewness in the downstream reach. Community-level health was impaired at the S i site based on an index of biological integrity (IBI), and physical habitat modifications were identified by a qualitative habitat evaluation index (QHEI). Overall, the model values for the integrative health response (IHR), developed using the star plot approach, were 3.22 (80.5%) at the S c site and 0.74 (18.5%) at the S i site, indicating that, overall, ecological health impairments were evident in the urban reach. Our study was based on multi-level approaches using biological organization and the results suggest that there is a pivotal point of linkage between mechanistic understanding and real ecological consequences of environmental stressors.

Effects of landscape‐scale forest change on the range contraction of ruffed grouse in New York State, USA

AbstractIn New York State, USA, the abundance of ruffed grouse (Bonasa umbellus) has declined &gt;75% since the 1960s. We hypothesized that range contraction of grouse in New York State was associated with broad‐scale spatial patterns relating to forest maturation and that these patterns would be evident at the landscape scale. We evaluated data available from New York Breeding Bird Atlases conducted in the early 1980s and again in the early 2000s, which included surveys of &gt;5,000, 25‐km2 sample blocks across a landscape of 125,384 km2. We related detection and non‐detection of grouse within Breeding Bird Atlas blocks to forest amount, landscape configuration, and presence of neighboring grouse populations via autologistic regression. Loss of early successional forest was inversely related to the continued persistence of grouse (R2 = 0.61). Models showed that ruffed grouse were no longer detected in marginal areas of their distribution, blocks with low amounts of forest, and blocks with landscape configurations potentially advantageous to nest predators. We conclude that declines in both habitat quality and quantity have contributed to range contraction within New York State and that the factors affecting grouse populations have acted at broader spatial scales than are typically considered in habitat evaluation. Our work demonstrates that large landscape‐scale data sets are valuable in assessing changes in distribution and abundance of wildlife populations. Landscape analyses at large geographic scales (&gt;100,000 km2) are of particular importance to managers because they represent ways of quantifying the influence of economic incentives and land‐use policy on habitats across large regions. © The Wildlife Society, 2012

The impact of discharge change on physical instream habitats and its response to river morphology

The impact of climate-induced discharge change on fish habitats, based on 1951–2008 time series, was investigated within the crystalline catchment of the Grosse Muhl River in Northern Austria. A significant trend change of air temperature, based on Mann–Whitney statistical testing, was recorded for spring 1989 (P = 98.9 %) and summer 1990 (P = 99.9 %). This led to a pronounced increase in summer low flow periods. Hydrodynamic-numerical (one-dimensional/two-dimensional) modelling was applied to simulate the changing habitat characteristics due to decreasing discharge in relation to various morphological patterns (riffle-pool/plane-bed reaches). Using bathymetric data, which were sampled on cross sectional measurements, we clearly determined that plane-bed reaches (featureless bed forms) are sensitive to climate-related, reduced discharge, whereas riffle-pool reaches continued to exhibit suitable physical fish habitats even under extreme low-flow conditions. The impact of the decreased summer discharge on instream habitats was strong for subadult and adult grayling which have been used as target fish species. In situ measurements in microhabitats (velocity/depth) revealed habitat suitabilities. These values were taken as biotic input for habitat evaluation on the micro scale. The findings clearly show that river morphology is a decisive parameter in terms of habitat preservation and restoration in the context of the future impacts of climate change (decreased discharge).

Fishing gear substitution to reduce bycatch and habitat impacts: An example of social–ecological research to inform policy

This study examined the feasibility of gear substitution as a means to reduce bycatch and habitat impacts of fisheries, using a social–ecological systems approach. The U.S. west coast sablefish fishery is an excellent subject for this study, because it permits three different gear types and has a problem with bycatch of overfished species. Bycatch rates were highest in trawls and lowest in pots. Combining interview data with findings from a previous study, affirmed that habitat impacts were highest with trawls and lowest with longlines. Interviews with 44 individuals analyzed using grounded theory yielded several common themes in the opinions of gear substitution. Positive opinion themes included that it would allow better management of the fish populations by reducing bycatch and would allow more business options, flexibility, and increased profit for some trawlers. The main negative opinion theme was that gear substitution could decrease landings needed to support shoreside infrastructure. Most stakeholder groups saw some benefit in gear substitution. Notably, the trawlers voiced a unanimous preference for converting to pots rather than longlines. A scenario analysis revealed that the preferable management option would be long-term gear conversion, but incentives are likely to be an important means of encouraging gear conversion. This ecological impacts rapid assessment provided a regional evaluation of bycatch and habitat impacts that had never been conducted before for these gear types. It also provided scientific support for a regulatory change that legally allows trawlers to practice gear substitution.

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.

群集の入れ子構造に着目した都市緑地の鳥類生息環境の分析

群集の入れ子構造に着目した都市緑地の鳥類生息環境の分析