Can protective attributes of artificial refuges offset predation risk in lizards?

Artificial refuges are often used to supplement habitat in areas where natural shelters have been degraded or removed. Although artificial refuges are intended to support particular species, they may be equally attractive and accessible to others, including predators. We explored the influence of snake predation risk and shelter attributes on the overnight use of different artificial refuges (timber, tiles, and iron) using the predator‐prey relationship between Boulenger's skink, Morethia boulengeri and the curl snake, Suta suta. We collected adult M. boulengeri from two bioregions in south‐eastern Australia: the Riverina, where the two species co‐occur, and the South Western Slopes, where S. suta does not occur. Two adult S. suta were collected for use as chemical donors. We conducted four experiments on overnight refuge choice to determine: (i) predator‐scent avoidance, (ii) artificial refuge preferences, (iii) a trade‐off between a preferred refuge and predator‐avoidance, and (iv) the effect of gap height on refuge preference. We found that skinks avoided predator‐scented refuges in favour of identical, but unscented refuges. Skinks preferred timber refuges, and most skinks maintained this preference when predator‐scent was added. However, when gap height was manipulated, skinks shifted to the refuge with the smallest gap. Skinks displayed complex regional variation in behaviour; skinks from both bioregions avoided predator‐scent, but in the trade‐off experiment, skinks from the South Western Slopes were less likely to avoid predator‐scented timber refuges than those from the Riverina. Our findings suggest that protective refuge attributes, such as small gap height, can offset the risk implied by predator‐scent within a refuge. This study highlights the need to consider predator‐prey interactions when designing and using artificial refuges for habitat restoration or biological monitoring.     

Distribution of plants in a California serpentine grassland: are rocky hummocks spatial refuges for native species?

Invasions by non-native taxa can have severe consequences for native species. In the heavily invaded serpentine grasslands of central California, many native species appear to be restricted to isolated outcrops of shallow serpentine soil, or hummocks, although the extent to which these hummocks function as refuges for native vegetation has never been quantified. We tested whether native plant species were restricted to hummocks within a serpentine grassland at the University of California Sedgwick Reserve near Santa Barbara, California by sampling species along hummock-grassland gradients. We also examined the influence of soil parameters, hummock area, proximity to other hummocks, and spatial location on species composition across 16 hummocks at this site. Both the hummocks and the surrounding grassland had high Mg, low Ca, and low Ca to Mg ratios typical of serpentine systems. Hummocks appeared to be more stressful environments because of their shallower soils, lower cation exchange capacity, and greater percent sand. Of the 27 most common plant species sampled along hummock-grassland transects, we identified 8 hummock specialists, 7 edge specialists, 8 matrix specialists, and 4 generalists. Importantly, both the hummock and matrix specialist groups included native species. Plant community composition was correlated with spatial positioning of the hummocks and with soil Ca, Na, K, and N. The number of species increased and community composition changed with increasing hummock area. Species composition was most similar among hummocks in close proximity to each other, and decreased with increasing distance between hummocks. Our results suggest that the community structure of serpentine grasslands is spatially complex and an effective management or restoration plan must address this complexity.     

Artificial refuges for wildlife conservation: what is the state of the science?

Artificial refuges are human-made structures that aim to create safe places for animals to breed, hibernate, or take shelter in lieu of natural refuges. Artificial refuges are used across the globe to mitigate the impacts of a variety of threats on wildlife, such as habitat loss and degradation. However, there is little understanding of the science underpinning artificial refuges, and what comprises best practice for artificial refuge design and implementation for wildlife conservation. We address this gap by undertaking a systematic review of the current state of artificial refuge research for the conservation of wildlife. We identified 224 studies of artificial refuges being implemented in the field to conserve wildlife species. The current literature on artificial refuges is dominated by studies of arboreal species, primarily birds and bats. Threatening processes addressed by artificial refuges were biological resource use (26%), invasive or problematic species (20%), and agriculture (15%), yet few studies examined artificial refuges specifically for threatened (Vulnerable, Endangered, or Critically Endangered) species (7%). Studies often reported the characteristics of artificial refuges (i.e. refuge size, construction materials; 87%) and surrounding vegetation (35%), but fewer studies measured the thermal properties of artificial refuges (18%), predator activity (17%), or food availability (3%). Almost all studies measured occupancy of the artificial refuges by target species (98%), and over half measured breeding activity (54%), whereas fewer included more detailed measures of fitness, such as breeding productivity (34%) or animal body condition (4%). Evaluating the benefits and impacts of artificial refuges requires sound experimental design, but only 39% of studies compared artificial refuges to experimental controls, and only 10% of studies used a before-after-control-impact (BACI) design. As a consequence, few studies of artificial refuges can determine their overall effect on individuals or populations. We outline a series of key steps in the design, implementation, and monitoring of artificial refuges that are required to avoid perverse outcomes and maximise the chances of achieving conservation objectives. This review highlights a clear need for increased rigour in studies of artificial refuges if they are to play an important role in wildlife conservation.     

The use of artificial reefs in enhancing fish communities in Singapore

Intense development of the coastal zone in Singapore has resulted in the degradation of much of the marine ecosystem. In order to restore and enhance fish communities of denuded areas, an artificial reef consisting of a tyre reef and a concrete reef, was established in the vicinity of the southern islands of Singapore. Results from fish visual censuses after the establishment of the artificial reef indicated an increase in numbers of juveniles and adults. A total of 37 and 32 fish species were recorded over a period of 1/2 years at the concrete and tyre reefs respectively. The dominant fish families were Pomacentridae, Labridae, Chaetodontidae, Apogonidae, Gobiidae and Nemipteridae. The artificial reefs also serve as a nursery ground for some species (e.g. Neopomacentrus sp.) which are important primary consumers of algae on natural reefs. Greater numbers of target (food-important) fishes were observed at the concrete reef while the tyre reef harboured more juveniles and smallersized adults. The results indicate that the concrete modules were more effective than the tyre reef in terms of fish abundance per unit volume. Such structures can enhance the biological resources of relatively unproductive areas.     

Quantitative proteomic analyses of the response of acidophilic microbial communities to different pH conditions

Extensive genomic characterization of multi-species acid mine drainage microbial consortia combined with laboratory cultivation has enabled the application of quantitative proteomic analyses at the community level. In this study, quantitative proteomic comparisons were used to functionally characterize laboratory-cultivated acidophilic communities sustained in pH 1.45 or 0.85 conditions. The distributions of all proteins identified for individual organisms indicated biases for either high or low pH, and suggests pH-specific niche partitioning for low abundance bacteria and archaea. Although the proteome of the dominant bacterium, Leptospirillum group II, was largely unaffected by pH treatments, analysis of functional categories indicated proteins involved in amino acid and nucleotide metabolism, as well as cell membrane/envelope biogenesis were overrepresented at high pH. Comparison of specific protein abundances indicates higher pH conditions favor Leptospirillum group III, whereas low pH conditions promote the growth of certain archaea. Thus, quantitative proteomic comparisons revealed distinct differences in community composition and metabolic function of individual organisms during different pH treatments. Proteomic analysis revealed other aspects of community function. Different numbers of phage proteins were identified across biological replicates, indicating stochastic spatial heterogeneity of phage outbreaks. Additionally, proteomic data were used to identify a previously unknown genotypic variant of Leptospirillum group II, an indication of selection for a specific Leptospirillum group II population in laboratory communities. Our results confirm the importance of pH and related geochemical factors in fine-tuning acidophilic microbial community structure and function at the species and strain level, and demonstrate the broad utility of proteomics in laboratory community studies.     

白龙江上游地区森林植被恢复能力的分析

通过对残存林分的天然更新能力、天然次生群落和人工恢复群落的生长状况调查,分析了白龙江上游地区森林植被的恢复能力。结果表明：在人工恢复植被的过程中,营造于海拔3000m以上的人工云杉(Picea asperata)幼林生长不良,没有成林地分布,而营造于海拔2700～3000m带的人工云杉幼林生长发育良好,并且已成林地的林分结构符合理想同龄林林分结构的分布规律,能够定向培育成森林资源;残存天然林分的更新表现为草类云杉林天然更新良好,残存箭竹云杉林、杜鹃岷江冷杉林(Abies faxoniana)和箭竹岷江冷杉林的天然更新不良;采伐迹地上天然次生群落生长良好,更新及时,正处于正向演替阶段。根据影响林分生长的主要因子(海拔、土壤厚度、坡度、坡向)和林分的实际恢复能力,将该地区划分为3个森林植被恢复类型区,并分别提出了相应的恢复措施。     

Comparative study of Spanish and Italian terrestrial small mammal coenoses from different biotopes in Mediterranean peninsular tip regions

A comparison of terrestrial small mammal coenoses belonging to nine different biotopes in the tips of the Iberian and Italian peninsulas was carried out using the pitfall trapping method. The influence of both habitat type and peninsular effect on composition of small mammal coenoses was analysed. In Southern Italy, 203 specimens belonging to seven species were trapped: Suncus etruscus (Savi, 1822), Crocidura suaveolens (Pallas, 1811), C. leucodon (Hermann, 1780), Microtus savii (de Sélys-Longchamps, 1838), Apodemus sylvaticus (L., 1758), A. flavicollis (Melchior, 1834) and Mus musculus domesticus Schwarz & Schwarz, 1943. In Southern Spain 428 specimens belonging to five species were trapped: Suncus etruscus, Crocidura russula (Hermann, 1780), Microtus duodecimcostatus (de Sélys-Longchamps, 1839), Apodemus sylvaticus and Mus spretus Lataste, 1883. The relative density of small mammals occurring in the nine Spanish sampling stations was twice that recorded in the Italian stations; however the number of species recorded in the different biotopes show similar mean values, ranging from three to five in Andalusia and from three to six in Calabria. Apodemus sylvaticus was the dominant species in the Calabrian stations, whereas Crocidura russula prevailed in Andalusia. The biotic diversity values are very similar in the Calabrian and Andalusian biotopes. By contrast, the Insectivora/Rodentia ratio was always higher in Andalusia. The more xerophytic biotopes showed greater similarities between the communities in Southern Spain and Southern Italy, while the cooler biotopes differed between these two peninsulas.     

The Behavioural Response of Mayfly Nymphs (Stenonema sp.) to Chemical Cues from Crayfish (Orconectes rusticus)

Artificial reef systems play an important role in the increase of natural production of biological marine resources and they have been deployed worldwide. In Portugal, seven artificial systems have been deployed along the southern coast of the Algarve. Research to date has focussed mainly on fish populations, particularly those of economical importance. The present work aims to study the macrobenthic communities of the artificial reef structures, as these will enhance the food resources and shelter, making the reefs more attractive to fish. In particular, we experimentally analysed the sequence of colonisation of macrobenthic communities of the Ancão artificial reef system, which was deployed in the summer of 2002. The study of the colonisation of benthic communities was done using samples of concrete cubic units (15 × 15 cm) that were suspended at the reef modules at a depth of 20 m, at the time of the reef immersion. Four replicate samples were collected by SCUBA diving from two groups of the Ancão reef every three months from the starting date. Sampling was done using essentially non-destructive methods to assess the percentage cover of macrobenthic organisms in both vertical and horizontal surfaces. The percentage cover of the taxonomic groups was compared within the different surfaces of the samples and between the two reef groups. The bottom surface of cubic samples had a significantly higher colonisation related to the dominance of barnacle cover, probably due to lower sedimentation levels. Samples from both reef groups showed a similar pattern of colonisation. Barnacles, bryozoans and serpulids dominated the samples three months immediately after the beginning of the experiment. Other invertebrates groups, such as Porifera, Hydrozoa, Anthozoa, other sessile Polychaeta, Decapoda, Gastropoda and Bivalvia, were more abundant after six months of colonisation.     

Effects of mine drainage on the river hayle,cornwall a) factors affecting concentrations of copper,zinc and iron in water,sediments and dominant invertebrate fauna

Concentrations of copper, zinc and iron were measured in waters, sediments and invertebrates collected from the River Hayle. In river water at least 70% of copper and iron was associated with the particulate fraction whereas 80% of zinc was in the soluble form. Although total concentrations of zinc in water exceeded those of copper approximately ten fold, copper predominated over zinc in the sediments by a factor of approximately three. Iron was the most abundant metal recorded in both water and sediments.Seasonal differences in total metal content of waters suggested that concentrations of copper, zinc and iron increased during. periods of high flow and decreased during lower flows. Copper concentrations in the sediment, unlike zinc and iron, showed markedly higher values during the summer sampling period when flows were minimal.In the free-living Trichoptera larvae, concentrations of copper and zinc in the tissue appeared to follow copper and zinc levels in the water. Similar relationships in Odonata and Plecoptera larvae were not obtained. Factors affecting animal/metal relationships are discussed with particular reference to adaptation shown by organisms exposed to high concentrations of heavy metals in their environment.Department of Applied Biology, Cambridge     

Heavy metal accumulation in aquatic animals around the gold mine area of Loei province,Thailand

This research was conducted to assess the water quality and the contamination of heavy metals in water, sediment, fish, and frogs, as well as bioaccumulation factors (BAFs) in fish and frogs around the gold mine area. The water samples were analyzed for water quality (temperature, pH, and dissolved oxygen). The samples were analyzed for heavy metals by inductively coupled plasma optical emission spectrometry. The water quality was within the standard. The concentrations of heavy metals, including As, Cr, Cd, Pb, Ni, Zn, Fe, Mn, and Cu, in water and sediment samples were measured. Three species of fish were collected: Rasbora tornieri, Brachydanio albolineata, and Systomus rubripinnis. The mean heavy metal concentrations of fish were as follows: Fe>Zn>Mn>Cr>Ni>Cu>As>Pb>Cd. The As, Cr, and Pb concentrations in all the fish species exceeded the standard levels. Five species of frogs were collected: Kaloula pulchra, Microhyla heymonsi, Fejervarya limnocharis, Hoplobatrachus rugulosus, and Microhyla pulchra. The mean heavy metal concentrations of frog were as follows: Fe>Cu>Mn>Zn>Cr>Ni>Pb>Cd>As. The Cr, Cd, and Cu concentrations exceeded the standard levels. The BAFs in fish were in order of Cr>Zn>Ni>Cu>Pb>Fe>Cd>As. The BAFs in frogs were Cr>Zn>Ni>Cu>Fe>Pb>Cd>As. The accumulation of heavy metals was higher in the sediment than in the water. Many aquatic organisms take up heavy metals directly from the environment around the gold mine.     

The maintenance of structural integrity in freshwater protozoan communities under stress

The structural assimilative capacity (ability to maintain biological integrity under stress) of protozoan communities from nine lakes in the area of the University of Michigan Biological Station, Pellston, Michigan, and six stations at Smith Mountain Lake, Virginia, were studied (1) to determine if communities from lakes of differing trophic state differ in their ability to assimilate various amounts of copper sulfate, and (2) to explore the possible influence of average density of individuals and/or qualitative differences in the types of species present on any observed differences in assimilative capacity.In both the northern Michigan and Smith Mountain Lake studies, a trend in response was demonstrated along the eutrophic-oligotrophic gradient; eutrophic communities had a greater structural assimilative capacity than did oligotrophic communities. Both mean species density and community composition appear to be important factors in the ability to maintain structural integrity.     

井冈山自然保护区蛾类多样性及人为干扰的影响

对井冈山自然保护区蛾类群落的多样性及其受人为干扰的影响进行了研究。结果显示：（1）人为干扰导致井冈山自然保护区蛾类群落构成有较大差别,严重干扰导致蛾类科数明显降低;物种数和个体数呈现出随着人为干扰加强而降低的趋势;蛾类各优势科在不同人为干扰样点的相对多度存在差异。（2）人为干扰导致蛾类主要科的物种数和个体数变化不同：尺蛾科、夜蛾科、毒蛾科和舟蛾科的物种数和个体数在人为干扰下降低;轻度和中度干扰导致螟蛾科和天蛾科的物种数和个体数升高,重度干扰下物种数和个体数降低;人为干扰导致灯蛾科的物种数和苔蛾科的个体数升高。（3）人为干扰导致蛾类群落Shannon多样性指数、Pielou均匀度指数降低,Berger-Parker优势度指数升高。（4）人为干扰对蛾类群落的物种数和个体数的时间动态影响较大,对Shannon指数和Pielou均匀度指数时间动态影响较小,导致Berger-Parker优势度指数时间波动幅度增大。（5）人为干扰导致样点间蛾类群落相似性较低。     

动物病毒传染性克隆技术研究进展

综述了6种动物病毒传染性克隆技术:重组质粒转染子挽救系统,PolI PoⅡ转录挽救系统,Bac操作系统,Cosmid操作系统,YAC操作系统以及Bacmid操作系统;涵盖了动物RNA病毒,DNA病毒以及昆虫杆状病毒;比较了各系统的优缺点和适应范围,指出了动物传染性克隆技术的应用前景.     

热带人工林土壤动物群落的次生演替和发展过程探讨

在广东小良地区的桉林迹地上,对不同林龄的阔叶混交林土壤动物的组成进行比较,探讨群落随林龄的增加而变化的过程。以多样性为基础,可将这里土壤动物群落的演替和发展分成3个阶段,即增长期、过渡期和稳定期。在林龄20多年后,群落发展可进入最后阶段。不同类群的演变程序:(1)湿生动物个体数逐渐增加,直至平稳;(2)昆虫中不稳定类群逐渐减少;(3)白蚁种群在增长期前段迅速增加,随后即在较低水平上受到控制;(4)蚯蚓在增长期后段才出现,并迅速成为优势类群。过渡期及其以前的蚯蚓种类主要为寒(虫宪)蚓属(Ocnerodrilus),稳定后为环毛蚓属(Pheretima)。