The utility of transient sensitivity for wildlife management and conservation: Bison as a case study

Developing effective management strategies is essential to conservation biology. Population models and sensitivity analyses on model parameters have provided a means to quantitatively compare different management strategies, allowing managers to objectively assess the resulting impacts. Inference from traditional sensitivity analyses (i.e., eigenvalue sensitivity methods) is only valid for a population at its stable age distribution, while more recent methods have relaxed this assumption and instead focused on transient population dynamics. However, very few case studies, especially in long-lived vertebrates where transient dynamics are potentially most relevant, have applied these transient sensitivity methods and compared them to eigenvalue sensitivity methods. We use bison (Bison bison) at Badlands National Park as a case study to demonstrate the benefits of transient methods in a practical management scenario involving culling strategies. Using an age and stage-structured population model that incorporates culling decisions, we find that culling strategies over short time-scales (e.g., 1–5 years) are driven largely by the standing population distribution. However, over longer time-scales (e.g., 25 years), culling strategies are governed by reproductive output. In addition, after 25 years, the strategies predicted by transient methods qualitatively coincide with those predicted by traditional eigenvalue sensitivity. Thus, transient sensitivity analyses provide managers with information over multiple time-scales in contrast to the long time-scales associated with eigenvalue sensitivity analyses. This flexibility is ideal for adaptive management schemes and allows managers to balance short-term goals with long-term viability.     

Assessing risks of disease transmission between wildlife and livestock: The Saiga antelope as a case study

Disease transmission between wildlife and livestock can undermine conservation efforts, either by challenging the viability of threatened populations, or by eroding public tolerance of actual or potential wildlife disease reservoirs. This paper describes the use of transmission models to assess the risk of disease transfer across the wildlife-livestock boundary, and to target control strategies appropriately. We focus on pathogens of the Saiga antelope (Saiga tatarica) and domestic ruminants in Central Asia. For both foot and mouth disease and gastrointestinal nematodes, the main risk is associated with infection of saigas from livestock, and subsequent geographical dissemination of infection through saiga migration. The chance of this occurring for foot and mouth disease is predicted to be highly dependent on saiga population size and on the time of viral introduction. For nematodes, the level of risk and predicted direction of transmission are affected by key parasite life history traits, such that prolonged off-host survival of Marshallagia in autumn enables infection of saigas and transfer northwards in spring. Field estimates of parasite abundance provide qualitative support for model predictions. The application of models as tools for the early evaluation of disease transmission between wildlife and livestock is discussed.     

Evaluation of cocoa- and coffee-derived methylxanthines as toxicants for the control of pest coyotes

Methylxanthines were quantified in coffee, tea, and chocolate products. Tarajuilie tea from India, cocoa powder, and cocoa nibs contained the highest levels of methylxanthines. Theobromine, caffeine, and theophylline combined in the ratios observed in tea and chocolate were ingested by coyotes. Although both mixtures induced acute toxicity, the symptoms accompanying the chocolate methylxanthine mimic were preferable. Manipulation of the ratios of methylxanthines in the chocolate mimic led to the identification of a 5:1 theobromine/caffeine mixture as a promising coyote toxicant. This mixture was then administered to coyotes using the coyote lure operative device (CLOD). Mortality occurred in every coyote that ingested any portion of the CLOD contents. These results indicate that mixtures of theobromine and caffeine have the potential to be developed into a selective, effective, and socially acceptable toxicant for the control of pest coyotes.     

Range-wide analysis of wildlife habitat: Implications for conservation

The range-wide habitat status of many endangered species is unclear. We evaluated the status and spatial distribution of the habitat of the endangered giant panda (Ailuropoda melanoleuca) across its entire geographic range (i.e., six mountain regions located in Sichuan, Shaanxi and Gansu provinces, China) by integrating field and remotely sensed data to develop a habitat distribution model. Results suggest that current suitable habitat corresponds to ca. 1/4 of the habitat baseline (i.e., maximum amount of habitat possible). The highest proportion of suitable habitat relative to the baseline is in the Qinling mountain region. Overall, around 40% of the suitable habitat is inside nature reserves, but the proportion of habitat inside them varied among different mountain regions, ranging from ca. 17% (Lesser Xiangling) to ca. 66% (Qinling). The habitat model also predicted the occurrence of potentially suitable habitat outside the currently accepted geographic range of the species, which should be further evaluated as potential panda reintroduction sites. Our approach is valuable for assessing the conservation status of the entire habitat of the species, for identifying areas with significant ecological roles (e.g., corridors), for identifying areas suitable for panda reintroductions, and for establishing specific conservation strategies in different parts of the giant panda geographic range. It might also prove useful for range-wide habitat analyses of many other endangered species around the world.     

Fatty acid patterns as biomarker for trophic interactions: Changes after dietary switch and starvation

Fatty acid (FA) analysis is becoming increasingly important for investigating trophic interactions in soil food webs. FA profiles of neutral lipids are affected by diet, and the occurrence and amount of certain FAs can reflect feeding strategies. However, to draw conclusions on feeding strategies in the field it is necessary to know physiological parameters of fatty acid metabolism such as the detection time and storage period of FAs. In this study we investigated the chronological change of FA biomarkers in the Collembola Heteromurus nitidus when switched between different food sources: leaves (Tilia europaea), a fungus (Chaetomium globosum) and two bacteria (Stenotrophomonas maltophilia, Bacillus amyloliquefaciens). Additionally, we followed the change of bacterial FA biomarkers during starvation. After 14 days of food deprivation bacterial FAs were still detectable in a sufficient amount to use them as dietary markers. Switching diet experiments demonstrated that FAs typical for a specific diet are already present after one day and are still detectable after 14 days of feeding on a different food source, suggesting that FA analysis can integrate the food choice of Collembola over a longer period of time, in contrast to snapshot methods such as gut content analysis.     

基于软X射线成像的储粮害虫米象生长阶段检测

为了准确检测单粒小麦内部是否感染米象（Sitophilus oryzae）,利用软X射线成像检测技术对感染不同生长阶段米象的小麦颗粒进行成像,试图通过图像分析来确定小麦内部米象的幼虫、蛹和成虫等不同生长阶段,并利用随机重复抽样建模来评价结果可靠性。通过对被感染米象虫卵不同天数小麦的图像分析发现,图像灰度分布直方图随感染天数变化明显,低灰度值区域（灰度值为10～102）的灰度区域像素点随感染天数增加而减少,中灰度（灰度值为103～162）和高灰度区域（灰度值为163～232)则随感染天数增加而增多。使用包括图像灰度分布和纹理特征等47个特征值,利用线性判别分析（Linear Discriminant Analysis,LDA）与二次判别分析（Quadratic Discriminant Analysis,QDA）建立判别模型,并通过多次随机重复抽样（1 000次）对模型预测效果进行评估分析。结果表明：在95% 置信区间下,在感染与未感染小麦的分类判别中,LDA的判别准确率都在76%以上,除幼虫外生长阶段判别正确率达到95%以上;而QDA的平均判别准确率较低且判别误差也相对较高。因此,该研究使用随机重复抽样方法LDA模型判别小麦是否受到米象感染和区分不同生长阶段是准确可靠的。     

Analysis of isothiocyanate mercapturic acids in urine: a biomarker for cruciferous vegetable intake

Cruciferous vegetables contain glucosinolates, which are degraded to isothiocyanates. These are easily absorbed, conjugated to glutathione, and excreted into the urine as their corresponding mercapturic acids. We have developed and validated a solid phase extraction-high-performance liquid chromatography-electrospray ionization mass spectrometry/mass spectrometry method for the specific analysis of individual isothiocyanate mercapturic acids in urine. The range of reliable analysis was 1.0-310 microM in urine. Urine samples fortified with three different levels of isothiocyanate mercapturic acids were measured on six different days by three independent technicians. The relative standard deviation (RSD) of repeatability was 12, 6, and 3%; the RSD of reproducibility was 19, 14, and 8%, and spike recoveries were 103, 104, and 103%, respectively, for 1.04, 10.5, and 313 microM levels. In 24 h urine collected from two volunteers after they consumed broccoli and cauliflower, clearly sulforaphane mercapturic acid (133 micromol) and allyl isothiocyanate mercapturic acid (4.7 micromol) were found. This procedure demonstrates a reliable and efficient method to study the intake and mode of action of isothiocyanates in animal studies and clinical trials.     

Design and management of continental wildlife reserves: Lessons from the everglades

Evidence from the attempt to preserve wading birds in Everglades National Park suggests that application of biogeographic theory to design and management of continental wildlife reserves requires considerations additional to those previously proposed. Shape and areal extent alone are inadequate criteria for reserve design. Unlike islands, continental reserves are not necessarily self-contained ecosystems driven by endogenous processes. The isolation of a continental reserve may lead to a phenomenon of ecosystem degeneration, the extent and rapidity of which depends on the ecological condition of adjacent habitat. Management strategies to preserve maximum species richness are seldom totally acceptable and often inherently unattainable. Conflicts between species management and ecosystem management illustrate the need for instituting an array of management strategies on a regional basis for preservation of both endangered species and ecosystems.     

Efficacy of road removal for restoring wildlife habitat: Black bear in the Northern Rocky Mountains, USA

Forest roads reduce habitat quality for wildlife, in part by increasing susceptibility to hunting and poaching. Road removal is an increasingly common strategy for restoring habitat; however, little is known about responses of wildlife to road removal versus other methods of road closure. We assessed effects of different types of road closure (gated, barriered, and recontoured) on black bear (Ursus americanus) frequency and habitat on 18 open and closed road pairs in the western USA. Over 4 years, 44 bears were photographed during 3545 camera-trap days. Bear frequency was significantly higher (2.4 versus 0.6/100 days, respectively) and human frequency was significantly lower (2.4 versus 361.6/100 days, respectively) on closed than on open roads. Additionally, abundance of fall foods was higher (23.9% and 12.8%, respectively) and line-of-sight (a measure of habitat security) shorter (54.9 versus 69.4 m, respectively) on closed compared to open roads. Bears were detected on closed but not on open roads during daytime, suggesting avoidance of humans. Among-road-treatment differences included significantly higher frequency of bears on recontoured than on gated or barriered roads (4.6, 1.6, and 0.5/100 days, respectively), and significantly higher cover of fall bear foods on recontoured than on gated or barriered roads (39.3%, 12.1% and 16.4%, respectively). Frequency of bears was negatively correlated with frequency of humans and line-of-sight distance and positively correlated with abundance of fall foods and hiding cover. Results suggest that while all types of road closure benefit sensitive wildlife, removal by recontour may be the most effective strategy for restoring habitat.     

Allocation of hunting effort by Amazonian smallholders: Implications for conserving wildlife in mixed-use landscapes

Most tropical forest landscapes are modified by humans, but the effects of these changes on rural hunting patterns and hunted vertebrate populations remain poorly understood. We investigated subsistence hunting patterns across a highly heterogeneous landscape mosaic in the Brazilian Amazon, where hunters from three villages had access to primary forest, active and fallow agricultural fields, and active and fallow Eucalyptus plantations. Landscape composition and the areas used by hunters were defined using a remote-sensing approach combined with mapping. We quantified hunting effort accounting for the availability and spatial distribution of each habitat. Overall, 71% of the kills were sourced in primary forest, but hunting in primary forest, which was often combined with other extractive activities (such as Brazil nut harvesting), yielded the lowest catch-per-unit-effort of all habitats. Hunting effort per unit area was highest in fallow fields, followed by primary forest, and both of these habitats were over-represented within village hunting catchments when compared to the composition of the available landscape. Active and fallow fields sourced a limited number of species known to be resilient to hunting, but hunting had additional benefits through crop-raider control. In contrast, hunting pressure in active and fallow plantations was low, despite a high catch-per-unit-effort, presumably because there were limited additional benefits from visiting these habitats. These results indicate that large-scale tree plantation and forest regeneration schemes have limited conservation potential for large vertebrates, as they support few forest specialists and fail to attract hunters away from primary forest.     

The spatial patterns of indigenous wildlife use in western Panama: Implications for conservation management

Measuring the impacts of indigenous hunting on neotropical wildlife populations remains a difficult task. Significant insights can be gained by analyzing the spatial patterns of hunting yields. This paper presents a geographic analysis of game captured by hunters in 59 households belonging to five neighbouring villages in western Panama over a period of 232 days. The locations of 1269 game kill sites within a hunting zone of 131 km² were documented with trained local investigators and then entered into a geographic information system with associated attribute data for analysis. Results show a heavy concentration of kill sites around the study communities. Nearly 90% of the total harvest by weight was captured within just 2 km of hunters’ homes. Yet, while several species are captured in large numbers close to home, others are caught closer to the outer peripheries of the shared hunting zone, suggesting that some degree of localized depletion may have occurred. The findings demonstrate the value of mapping the boundaries of hunting zones and game kill sites to assess the impacts of hunting on game species in tropical and other ecosystems and to provide an empirical basis for delimiting conservation zones that balance the use and protection of wildlife in tropical forest regions.     

Indigenous collaborative research for wildlife management in Amazonia: The case of the Kaxinawá, Acre, Brazil

Wildlife is a critical food resource throughout Amazonia. Consequently, adaptive management based on continued resource evaluation is essential to ensure long-term sustainable use of Amazonian wildlife. Since 1996, the Kaxinawá people of Western Amazonia have participated in a capacity-building program focused on natural resource management leading to the development of a territorial management plan that includes monitoring of wildlife use. In this study, we report the results of collaborative management-oriented research where hypotheses designed by the Kaxinawá about game availability within their territory were supported by the analysis of self-monitoring hunting data collected through a methodology designed in collaboration with conservation biologists. Results support Kaxinawá hypotheses that: (1) there is variation of game availability among villages in Kaxinawá territory; (2) preferred game species are more available to those villages closest to the isolated headwaters; and (3) previous land and wildlife use, present density of villages, and human population density are the main factors causing observed variations of game availability. The results of this study suggest the relevance and value of long-term participatory studies to complement short-terms academic studies of biodiversity and natural resource use and management.     

Lynx reintroductions in fragmented landscapes of Germany: Projects with a future or misunderstood wildlife conservation?

Eurasian lynx are slowly recovering in Germany after an absence of about 100 years, and additional reintroduction programs have been launched. However, suitable habitat is patchily distributed in Germany, and whether patches could host a viable population or contribute to the potential spread of lynx is uncertain. We combined demographic scenarios with a spatially explicit population simulation model to evaluate the viability and colonization success of lynx in the different patches, the aim being to conclude guidelines for reintroductions. The spatial basis of our model is a validated habitat model for the lynx in Germany. The dispersal module stems from a calibrated dispersal model, while the demographic module uses plausible published information on the lynx’ life history. The results indicate that (1) a viable population is possible, but that (2) source patches are not interconnected except along the German-Czech border, and that (3) from a demographic viewpoint at least 10 females and 5 males are required for a start that will develop into a viable population with an extinction probability of less than 5% in 50 years. The survival rate of resident adults was the most sensitive parameter, and the best management strategy for the success of reintroduction would be to reduce the mortality of residents in the source patches. Nevertheless, the extremely low probability of connectivity between suitable patches makes most of the reintroduction plans isolated efforts, and they are therefore questionable in the long run. With such a model, the suitability of the single habitat patches can be assessed and the most appropriate management scheme applied. This study shows that simulation models are useful tools for establishing the comparative effectiveness of reintroduction plans aimed at increasing the viability of the species.     

Bile acids combined with fecal sterols: a multiple biomarker approach for deciphering fecal pollution using river sediments

Journal of Soils and Sediments - Fecal sterols (FSs) and bile acids (BAs) are biomarkers that can be used to track sewage pollution. These biomarkers offer an alternative to microbiological...     

The development of a new approach for establishing a core collection using multivariate analyses with tulip as case

A methodology is developed for the establishment of a core collection based on phenotypic data. A case is worked out for the tulip cultivar collection of the Hortus Bulborum, consisting of approximately 1000 cultivars. The methodology is based on cluster analysis of phenetic characters, selection of cultivars from the resulting clusters according to a combination of the proportional and genetic diversity dependent strategies, optimisation of the selection, and validation by means of principal component analysis and by the diversity indices of Nei and Shannon & Weaver. A core collection with 104 cultivars (approx. 10%: CORE-1) did not give a sufficient representation of the existing diversity. A set of 152 cultivars (approx. 15%: CORE-2) showed a far better representation. The variation in resistance levels for Fusarium is almost completely represented in CORE-2. Although a set of 200 cultivars (approx. 20%: CORE-3) reached a nearly complete representation of the total diversity, a better representation of the resistance levels was not achieved. The newly presented methodology for defining a core collection appears to be a useful approach. The included steps for optimising and validating the choice of accessions makes it a reliable and broadly applicable method.     

Commercial agriculture as creative destruction or destructive creation: a case study of chili cultivation and plant‐pest disease in the southern Yucatán region

Agricultural change encompasses both social and ecological alterations, some negative, some positive. Studies of land change and land degradation treat plant pest and diseases triggered by agricultural change in an inconsistent fashion. A study of the southern Yucatán region of Mexico reveals that the shift to commercial chili cultivation yields both positive and negative consequences, akin to the concepts of creative destruction and destructive creation. The negative consequences are dramatically amplified by persistent plant pest and diseases apparently triggered by the means of cultivation and by the inclusion of the region into a national marketing structure. Thus, while providing economic benefits to some of the farmers of the region the short‐ and long‐term impacts of chili cultivation on farmer households is mixed. Studies of agricultural land‐use change and household economics will benefit by incorporating plant pests and diseases as one of the suite of factors involved in land degradation. Copyright © 2004 John Wiley & Sons, Ltd.     

Analysis of O,S-dimethyl hydrogen phosphorothioate in urine, a specific biomarker for methamidophos

A rugged and sensitive method was developed to monitor urinary concentrations of O,S-dimethyl hydrogen phosphorothioate (O,S-DMPT), a specific biomarker of exposure to the organophosphate insecticide methamidophos. After pH adjustment and C18 solid phase extraction column cleanup, the urine was lyophilized at a low temperature to prevent loss of possibly highly volatile and unstable O,S-DMPT metabolite. The dried residue was derivatized using N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide and 1% tert-butyldimethylchlorosilane (MTBSTFA + 1% TBDMCS) in acetonitrile. After it was filtered, the derivatized product was analyzed and quantified by gas chromatography using a pulse flame photometric detector specific for phosphorus compounds. The limit of detection for this method was 0.004 ppm with a limit of quantitation of 0.02 ppm of urine. The mean recovery value for O,S-DMPT from 17 urine samples fortified at varying concentrations was 108% with a standard deviation of 12%.     

Effects of amendments on soil structural development in a clay soil-forming material used as a cap for landfill restoration

Abstract. Restoration of landfill sites to a vegetated after-use is severely compromised if soil-forming materials (SFMs) have to be used as substitute growing media for the restoration cap, owing partly to their poorly-developed structure. The effects of crushed brick material (brick), composted green-waste organic matter (OM) and potassium chloride salt (KCl) in a clay SFM were assessed at the Brogborough Landfill Site (Shank Group plc) in the county of Bedfordshire, UK. Soil structure was characterized three times in a two-year experimental period through measuring drainage water release and aggregate stability and size distribution. Crushed brick and composted OM at 100 t ha⁻¹ improved the ability of the clay to release water by drainage. In addition, the composted OM was associated with an increase in the size of stable aggregates, whereas the brick amendment reduced the overall aggregate stability. The KCl amendment had no consistent effect. Some beneficial structural improvements were thus associated with the brick and OM amendments, although these were rarely significant at the 5% level and the effects declined over time in the absence of vegetation and re-application. Nevertheless, incorporation of crushed brick and organic amendments may offer a potential structure-improving option in clay SFMs prior to vegetation establishment.     

Importance, cause and effect of bushmeat hunting in the Udzungwa Mountains, Tanzania: Implications for community based wildlife management

Community Based Wildlife Management (CBWM) has been suggested as a conservation strategy in response to bushmeat hunting in the Udzungwa Mountains within the Eastern Afromontane biodiversity hotspot. The feasibility of CBWM based on meat cropping was therefore evaluated in New Dabaga/Ulangambi Forest Reserve (NDUFR). Comparison of relative wildlife densities with West Kilombero Scarp Forest Reserve, which is subject to only low hunting pressure, indicate that most relevant populations are severely depleted (Cephalophus monticola, C. harveyi and C. spadix, Potamochoerus larvatus) and hence that sustainable harvesting currently is not possible in NDUFR. Records of catch from hunters in the villages surrounding NDUFR indicate that bushmeat is of relatively low importance in terms of use and contribution to protein intake. Proximity to NDUFR and secondarily population size in the different villages is positively correlated with hunting intensity and depletion of wildlife. Comparisons between hunters and non-hunters in terms of wealth measures show that hunting is linked to poverty and low protein intake. An estimation of maximum sustainable harvest in NDUFR reveals that CBWM only has limited capacity to reduce these causes of hunting, maintain the communities’ interest and offset the opportunity costs of conservation. Results of this study suggest that conservation efforts in NDUFR should focus on protecting wildlife against exploitation instead of encouraging use and dependence through CBWM. Supporting efforts should attempt to facilitate a complete shift to domestic sources of meat, by increasing the number of domestic animals in the poorest part of the population.     

数字土壤及其应用研究进展

  目的  为实现土壤剖面信息的快速采集,并保证数据的一致性与完整性。  方法  在土壤信息采集现状分析基础上,遵照MVC设计规范,采用SQLite数据库,基于iOS操作系统设计并开发了土壤剖面信息采集系统。  结果  土壤剖面信息采集系统设计了2个主表与83个查找表,方便用户快速录入剖面相关信息,增强交互界面友好性和数据规范化,开发了基于iOS系统的App程序,可以通过iPhone或iPad安装使用。  结论  通过系统测试及应用,表明利用该App进行土壤剖面信息采集系统切实可行,在土壤剖面信息采集方面具有很好的数据一致性,减少后期录入与整理的人工成本,可为科研工作者野外土壤剖面采样及第三次土壤普查等工作提供技术支撑,具有较强的应用价值。