Circadian rhythms enable efficient resource selection in a human‐modified landscape

Animals access resources such as food and shelter, and acquiring these resources has varying risks and benefits, depending on the suitability of the landscape. Some animals change their patterns of resource selection in space and time to optimize the trade‐off between risks and benefits. We examine the circadian variation in resource selection of swamp wallabies (Wallabia bicolor) within a human‐modified landscape, an environment of varying suitability. We used GPS data from 48 swamp wallabies to compare the use of landscape features such as woodland and scrub, housing estates, farmland, coastal areas, wetlands, waterbodies, and roads to their availability using generalized linear mixed models. We investigated which features were selected by wallabies and determined whether the distance to different landscape features changed, depending on the time of the day. During the day, wallabies were more likely to be found within or near natural landscape features such as woodlands and scrub, wetlands, and coastal vegetation, while avoiding landscape features that may be perceived as more risky (roads, housing, waterbodies, and farmland), but those features were selected more at night. Finally, we mapped our results to predict habitat suitability for swamp wallabies in human‐modified landscapes. We showed that wallabies living in a human‐modified landscape selected different landscape features during day or night. Changing circadian patterns of resource selection might enhance the persistence of species in landscapes where resources are fragmented and disturbed.     

基于“源-汇”理论的流域非点源污染控制景观格局调控框架——以厦门市马銮湾流域为例

基于“源-汇”理论对景观格局进行调控与优化是一种较为经济、有效的流域非点源污染控制新方法,目前尚处在探索阶段.在景观生态学及相关理论与前人已有研究的基础上,以流域整体为对象,从2个层次构建基于“源-汇”理论的流域非点源污染控制景观格局调控框架: 1)流域层次:在分析流域“源-汇”景观合理的基本组合与空间布局方式的基础上,建立了流域景观格局整体调控与优化方法;2)景观斑块类型层次:将关键“源”景观作为重点调控与优化对象,建立了包含景观单位面积污染负荷、景观坡度、起传输作用的狭长“源”景观、临河“源”景观单位岸线长度污染负荷等4项关键“源”景观识别准则,并遵循镶嵌“汇”景观、局部增补带型“汇”景观、提高原有“汇”景观消纳污染物的能力等3项调控与优化原则,针对农村地区与城区不同的关键“源”景观类型,制定了9类调控与优化方法.最后将该框架应用到厦门市马銮湾流域,基于GIS平台及研究区遥感图像与数字高程模型,制定了马銮湾流域景观格局整体调控与优化模式及3个片区关键“源”景观调控与优化方案.     

Mammal responses to matrix development intensity

The landscape matrix is increasingly being recognized as important to biodiversity conservation. The nature of the matrix impacts the persistence of species in human‐modified landscapes through its pervasive influence on adjacent habitat and through the habitat value of the matrix itself. However, previous studies have not isolated the effects of the matrix from the effects of other aspects of landscape modification, such as habitat loss and fragmentation, and much remains to be understood about the independent impact of the matrix on wildlife. We investigated the effects of the matrix on mammal abundance and landscape use in south‐east Queensland, Australia. Mammals were surveyed in patch ‘core’, patch ‘edge’ and ‘matrix’ landscape elements along a rural–suburban gradient of matrix development intensity quantified by a weighted road‐length metric, which was significantly correlated with housing density, while controlling for potentially confounding patch and landscape attributes. Response to increasing matrix development intensity was highly species‐specific. Several native species declined in abundance; however, others were more resilient to moderate levels of matrix intensity, one species increased in abundance, and at least one species appeared unaffected by matrix intensity. Native species richness peaked at moderate levels of matrix development intensity. Exotic species richness and feral predators increased with matrix intensity and were negatively correlated with native species. Species response to matrix intensity appeared related to their use of edge or matrix habitat. An ability to use the matrix per se, however, may not translate into an ability to persist in a landscape where development substantially reduces the habitat or movement value of the matrix.     

城市化地区河岸带植被特征及其与河岸硬度的关系——以晋江市为例

确立了滨河河道硬度与滨河土地硬度两个指标,用以研究城市化地区河岸带的植物构成、多样性与均匀度、优势植物等特征与河岸硬度的关系。选定晋江市都市区12条主要河流作为研究对象,通过样地调查收集数据,并采用相应指数进行数据处理分析,结果表明:(1)调查河流的河岸带植被物种共计70科143属159种,其中乔木20科30属41种,灌木15科15属20种,草本35科98属98种,草本居主导地位,河流间种类分布不均衡;(2)河岸带植物乔灌草区系均以广义热带性成分居多,其次为世界性成分、温带性成分,无中国特有分布类型,乔木中广义热带成分占绝对主导,直观反映地带性特征,灌木与草本中的温带成分多于乔木中的温带成分,类型趋于多元,种类更丰富;(3)从河岸植被优势植物构成来看,主要优势乔木与灌木基本为本土植物,而主要草本中外来植物入侵严重,对地带性植物景观的指示显然不及乔木与灌木;(4)从河岸植被的人工美学属性来看,灌木优势植物中园林观赏植物的种类数显著多于乔木、草本优势植物,反映出晋江人工审美主导的滨河景观空间主要改变与塑造了灌木层植被景观;(5)从河岸植物的人居需求属性来看,龙眼、杨桃等多见于庭院林、水岸林的水果树种也在河岸植被中频繁出现,反映出人口密集区由于对植物生产用途的重视而对河岸植被产生的影响;(6)滨河土地硬度与河道硬度对河岸带灌木植物的影响最强烈,二者均对河岸带植物多样性造成威胁,且前者具有更大的影响力,而后者直接影响了河岸植物的分布形态,出于生产与审美目的的人为干扰对河岸带植物优势种的影响力随滨河硬度的增加而加强,低滨河硬度有助留存原生植被群落;(7)天然弯曲的河流形态对河流植被特征具有积极影响,有助于保留更多本土植被类型,并能在某种程度上丰富乔灌草的植物种类,但这种缓和作用无法根本扭转河岸硬化对植物多样性的胁迫影响。研究表明,城市化地区河流的岸带植被特征与沿线人为干扰类型和强度密切相关,恢复与塑造河岸生态景观要以乡土植被为主,通过乔木景观塑造地带性景观,并以灌木与草本丰富植被景观。     

The trade-off between housing density and sprawl area: Minimising impacts to forest breeding birds

Increasing housing density is generally assumed to confer negative effects on forest breeding birds. This implies we should build at low density over the landscape to conserve these species. However, for a given human population, low-density development must cover a large area, resulting in sprawl. A pertinent question is then: at what housing density are the impacts of a given human population on forest biodiversity minimised? For a given human population, it is unclear whether the impacts on forest biodiversity are less where housing density is high and sprawl area is small or where housing density is low and sprawl area is large. We addressed this question using the abundance, species richness and evenness of forest birds in Ottawa, Ontario and Gatineau, Quebec, Canada. First, we counted breeding birds at 22 sites representing a range of housing densities. We then used these empirical measurements to estimate forest bird abundance, species richness and evenness in four hypothetical development scenarios representing the trade-off between housing density and sprawl area. With the exception of the Undeveloped scenario (i.e., continuous forest), forest birds and forest interior birds were most abundant in the Compact scenario and most speciose in the Semi-compact scenario, whereas forest edge birds were most abundant and speciose in the Dispersed scenario. All three bird groups were most even in the Compact scenario. We conclude that compact housing development (building at high density over a small area) minimises the impacts of a given human population on forest breeding birds.     

Soil bioengineering and the ecological restoration of riverbanks at the Airport Town,Shanghai, China

Ecological, soil bioengineering, and traditional techniques were integrated to obtain a structurally sound, ecologically sustainable and socio-economically beneficial method for restoring the riverbanks at the Airport Town, Shanghai, which was the first project applying soil bioengineering to riverbank restoration in China. Soil bioengineering is the use of living plant materials to construct structures that perform some engineering and ecological functions and can provide an effective means for slope stabilization and site restoration of riverbanks. The restoration and management strategy was based on a plan to integrate the natural landscape using live staking, live fascines, brush layer, vegetated geo-grids and geo-gabions, along with native vegetation for riverbank preservation. Ecological parameters including root characteristics and their biomass, species and habitat diversity, and soil moisture and shear stress were measured for site characterization and evaluation of a demonstration project The riverbank erosion was reduced significantly, along with an increase in species and habitat diversity, and improvement in aesthetics and water quality after a ten-month project implementation period, when compared to the control site. Our project of ecological restoration of riverbanks can be viewed through the perspective of the 19 principles presented by Mitsch and Jorgensen, which shows also how the principles and methods of soil bioengineering, and the concepts of ecological engineering that have recently been much developed in the West have been absorbed into Chinese practices of ecological engineering and can be applied to ecological restoration of riverbanks in China.     

高集约化农业景观中不同利益相关者的景观偏好

集约化农业是现代农业的生产经营方式,在提高农田单位面积产量的同时却带来了一系列环境和生态问题,限制了农业的可持续发展.景观偏好是景观生态学中探讨不同利益相关者对景观产生不同喜好的研究,能够反映人类的主观感受及其产生的行为对景观造成的影响.本文以河南省封丘县农业景观为例,通过问卷调查和其他相关方法综合分析了不同利益相关者所偏好的景观特征以及产生差异的原因,并为将来研究区农业景观的发展提出建议.结果表明: 封丘县的当地利益相关者更偏好简单规则且容易管理的景观要素,强调农业景观的生产及经济功能;专家和当地环保人士更偏好多功能兼具的景观要素,以及高异质性的复杂景观构型,倾向于发展多功能农业景观;文化程度、专业背景、受访者类别等因素均对研究区利益相关者的景观偏好存在明显影响.政府的决策行为、经济补偿程度、生态农业技术支持是影响并决定研究区景观结构和功能发生演变的重要因素.     

基于GIS和Fragstats的土地生态质量综合评价——以湖北省仙桃市为例

借助GIS和Fragstats的分析技术,结合土地利用类型数据,从土地生态系统的景观特征、生境质量的抗干扰能力和社会经济效益3个方面构建土地生态质量综合评价研究模型,采用改进熵权法确定其指标权重。以湖北仙桃为例,探究其三者的空间演变关系,并在此基础上对其土地生态质量进行综合评价。结果表明:(1)仙桃市土地生态质量整体水平偏低,且呈现出中间高,两侧低,且西翼高于东翼的空间分异特征。其中危险、临界安全、较安全和安全各等级,分别占总面积的21.52%、43.48%、27.10%和7.90%。(2)安全区主要分布在经济、政策优势最凸出及景观格局整体规划较好的中北部中心城区。在此区域景观特征、生境质量的抗干扰能力和社会经济效益之间呈现相互增益的协同发展态势。(3)较安全和临界安全区则主要集中分布在土地景观格局较好,开发程度较低的西翼地区。危险区则主要分布在生境质量抗干扰能力水平低的东翼地区。在东西两翼内景观特征、生境质量的抗干扰能力和社会经济效益之间的协同性较差,且两两之间的发展矛盾凸出。研究结果可为仙桃市全域土地综合整治项目的实施提供理论支持和其他类似地区提供案例参考。     

Ecological processes in urban landscapes: mechanisms influencing the distribution and activity of insectivorous bats

Urbanisation affects indigenous fauna in many ways; some species persist and even increase in urban areas, whereas others are lost. The causative mechanisms determining changes in distributions and community structure remain elusive. We investigated three hypothesized mechanisms, which influence success or failure of the insectivorous bat assemblage across the urban landscape of Sydney, Australia; landscape heterogeneity (diversity of land uses), productivity (as indexed by landscape geology) and trait diversity. We present data on species richness and activity (bat passes per night) collected systematically using ultrasonic bat detectors from randomly selected landscapes (each 25 km²). Landscapes were categorized into classes including ‘urban’, ‘suburban’ and ‘vegetated’, where suburban sites were additionally stratified based on geology, as a proxy for productivity. Four landscape elements were sampled within each landscape, including remnant bushland (>2 ha), riparian areas, open space/parkland and residential/built space. We found that there was significantly greater bat activity and more species of bat in areas on fertile shale geologies (p<0.05), supporting the productivity, rather than the heterogeneity hypothesis. Within landscapes, there was no significant effect of the landscape element sampled, although bushland and riparian sites recorded greater bat activity than open space or backyard sites. Using general linear mixed models we found bat activity and species richness were sensitive to landscape geology and increasing housing density at a landscape scale. Using an RLQ analysis a significant relationship was found between these variables and species traits in structuring the community present (p<0.01). Specifically, open‐adapted bats were associated with areas of greater housing density, while clutter‐adapted bats were uncommon in urban areas and more associated with greater amounts of bushland in the landscape. Overall we found greater support for the productivity and traits hypotheses, rather than the heterogeneity hypothesis. The degree of urbanisation and amount of bushland remaining, in combination with landscape geology, influenced bat activity and mediated the trait response. Our findings reflect global trends of species diversity and abundance in urban landscapes, suggesting that processes affecting bat species distribution in urban ecosystems may be predictable at a landscape scale.     

固化河岸对长江江豚栖息活动的影响

长江江豚主要栖居在近岸浅水水域,喜好泥沙质类型的河岸。但在长江干流,有很多自然河岸被固化,河岸固化给长江江豚分布和栖息活动造的影响仍不甚清楚。2016年3月—2017年1月,对长江干流2个自然河段江豚的数量和分布做了12次考察,并收集了这2个河段岸型的相关数据,来分析固化河岸对江豚栖息活动的影响。12次考察累计发现江豚215头次,平均每次考察观察到江豚(17.92±7.09)头次。研究区域的固化河岸约占岸线总长的59%,分析发现,仅约13.9%的江豚分布在固化河岸水域,86.1%的江豚均分布在自然河岸水域。江豚在单位河岸长度的分布数量与该段固化河岸长度所占的比例呈显著负相关(r=-0.639,P0.01)。在自然河岸,分布在近岸50 m水域的江豚占31.8%,而在固化河岸,仅观察到2头江豚活动在近岸50 m水域内。由此可见,固化河岸对江豚的近岸分布有明显影响。调查还发现,安庆城区建设带约10 km江段12次考察均未发现江豚分布,城区建设带可能对江豚栖息已造成严重影响。长江干流的固化河岸所占比例非常高,研究结果提示这可能导致长江干流江豚栖息地的丧失和破碎化加剧,在制定长江江豚保护措施必需慎重考虑此因素的影响,并据此提出相应的栖息地保护和恢复方案。     

Local adaptation of the trematode Fasciola hepatica to the snail Galba truncatula

Experimental infections of six riverbank populations of Galba truncatula with Fasciola hepatica were carried out to determine if the poor susceptibility of these populations to this digenean might be due to the scarcity or the absence of natural encounters between these snails and the parasite. The first three populations originated from banks frequented by cattle in the past (riverbank group) whereas the three others were living on islet banks without any known contact with local ruminants (islet group). After their exposure, all snails were placed in their natural habitats from the end of October up to their collection at the beginning of April. Compared to the riverbank group, snails, which died without cercarial shedding clearly predominated in the islet group, while the other infected snails were few in number. Most of these last snails released their cercariae during a single shedding wave. In islet snails dissected after their death, the redial and cercarial burdens were significantly lower than those noted in riverbank G. truncatula. Snails living on these islet banks are thus able to sustain larval development of F. hepatica. The modifications noted in the characteristics of snail infection suggest the existence of an incomplete adaptation between these G. truncatula and the parasite, probably due to the absence of natural contact between host and parasite.     

土地经济生态位在县域景观格局分析中的应用——以新疆精河县为例

本文将土地经济生态位的理论和方法引入到景观生态学当中,为区域景观格局表征提供了新的方法.选择典型的生态脆弱区精河县为研究对象,以1990、1998、2011和2013年4期Landsat影像为数据源,运用生态位态势理论计算研究区各土地利用类型的土地经济生态位,并结合景观生态学理论探讨土地经济生态位在县域景观格局分析中的应用.结果表明: 研究期间,精河县耕地、建设用地和草地的土地经济生态位与相应的景观斑块数、聚合度、破碎化指数和分维数具有较好的相关性;土地经济生态位的变化对县域景观格局具有驱动作用,可表征精河县经济发展方向.土地经济生态位与可直接获得经济效益的土地利用类型关系密切,且与景观指数相结合能够很好地解释精河县景观格局的特征.     

A review of sow and piglet behaviour and performance in group housing systems for lactating sows

Commercial use of group housing systems for lactating sows is limited, but the recent transition to group housing during gestation in the EU may result in a renewed interest in such systems. Therefore, this review aims to identify key factors that may contribute to the success or failure of group housing of lactating sows in comparison with individual housing by describing the variety in group housing systems and discussing animal behaviour and performance compared with individual housing. Group housing systems can be divided in multi-suckling (MS) systems, in which sows are grouped with their litters, and get-away (GA) systems, which include a separate communal area accessible to sows only. These systems differ in many aspects regarding management and layout but, compared with individual housing, generally provide more environmental complexity, more freedom of movement for the sows and more freedom to express behaviours related to, for example, maternal care and social interactions. Group housing poses several risks, such as disrupted nursing and an increased level of crushing during the MS phase, and in the GA systems there is a risk for early cessation of nursing. On the other hand, pre-weaning mingling of litters clearly benefits piglet social development and may improve adaptation to the post-weaning situation. In addition, group-housed sows may show lactational ovulation, which provides opportunities for insemination during an extended lactation period, which benefits the piglets. Gradual transitions in social and physical environment around gestation, farrowing, grouping and weaning seem to be key success factors for group housing systems during lactation. In addition, selection of suitable sows and quality of stockmanship seem important.     

Housing environment and early childhood development in sub-Saharan Africa: A cross-sectional analysis

BackgroundThe influence of the safety and security of environments on early childhood development (ECD) has been under-explored. Although housing might be linked to ECD by affecting a child’s health and a parent’s ability to provide adequate care, only a few studies have examined this factor. We hypothesized that housing environment is associated with ECD in sub-Saharan Africa (SSA).Methods and findingsFrom 92,433 children aged 36 to 59 months who participated in Multiple Indicator Cluster Survey (MICS) in 20 SSA countries, 88,271 were tested for cognitive and social–emotional development using the Early Childhood Development Index (ECDI) questionnaire and were thus included in this cross-sectional analysis. Children’s mean age was 47.2 months, and 49.8% were girls. Children were considered developmentally on track in a certain domain if they failed no more than 1 ECDI item in that domain. In each country, we used conditional logistic regression models to estimate the association between improved housing (housing with finished building materials, improved drinking water, improved sanitation facilities, and sufficient living area) and children’s cognitive and social–emotional development, accounting for contextual effects and socioeconomic factors. Estimates from each country were pooled using random-effects meta-analyses. Subgroup analyses were conducted by the child’s gender, maternal education, and household wealth quintiles. On-track cognitive development was associated with improved housing (odds ratio [OR] = 1.15, 95% CI 1.06 to 1.24, p < 0.001), improved drinking water (OR = 1.07, 95% CI 1.00 to 1.14, p = 0.046), improved sanitation facilities (OR = 1.15, 95% CI 1.03 to 1.28, p = 0.014), and sufficient living area (OR = 1.06, 95% CI 1.01 to 1.10, p = 0.018). On-track social–emotional development was associated with improved housing only in girls (OR = 1.14, 95% CI 1.04 to 1.25, p = 0.006). The main limitations of this study included the cross-sectional nature of the datasets and the use of the ECDI, which lacks sensitivity to measure ECD outcomes.ConclusionsIn this study, we observed that improved housing was associated with on-track cognitive development and with on-track social–emotional development in girls. These findings suggest that housing improvement in SSA may be associated not only with benefits for children’s physical health but also with broader aspects of healthy child development.

In a cross-sectional analysis of nationally representative survey data from 20 countries, Yaqing Gao and colleagues investigate associations between housing environment and cognitive and social development in children.     

Sample design effects in landscape genetics

An important research gap in landscape genetics is the impact of different field sampling designs on the ability to detect the effects of landscape pattern on gene flow. We evaluated how five different sampling regimes (random, linear, systematic, cluster, and single study site) affected the probability of correctly identifying the generating landscape process of population structure. Sampling regimes were chosen to represent a suite of designs common in field studies. We used genetic data generated from a spatially-explicit, individual-based program and simulated gene flow in a continuous population across a landscape with gradual spatial changes in resistance to movement. Additionally, we evaluated the sampling regimes using realistic and obtainable number of loci (10 and 20), number of alleles per locus (5 and 10), number of individuals sampled (10–300), and generational time after the landscape was introduced (20 and 400). For a simulated continuously distributed species, we found that random, linear, and systematic sampling regimes performed well with high sample sizes (>200), levels of polymorphism (10 alleles per locus), and number of molecular markers (20). The cluster and single study site sampling regimes were not able to correctly identify the generating process under any conditions and thus, are not advisable strategies for scenarios similar to our simulations. Our research emphasizes the importance of sampling data at ecologically appropriate spatial and temporal scales and suggests careful consideration for sampling near landscape components that are likely to most influence the genetic structure of the species. In addition, simulating sampling designs a priori could help guide filed data collection efforts     

我国南方典型红壤区景观格局对崩岗侵蚀的影响

崩岗是地质构造、地貌条件、气象水文、植被、人类活动等综合作用下形成的一种复合侵蚀地貌,崩岗的形成与发展已严重制约了当地农业生产和社会经济发展。通过调整土地利用结构方式、优化景观格局是防治红壤区崩岗侵蚀的重要手段。如何从斑块类型水平揭示景观格局与崩岗侵蚀的关系,对于控制崩岗侵蚀、提高生态环境效益具有重要意义。以福建省安溪县为例,运用ArcGIS水文分析工具和DEM数据将该区域划分为53个子流域,以崩岗面积与密度为响应变量,景观格局指数为解释变量,采用冗余分析(RDA)法和通径分析法,从斑块类型水平探讨景观格局指数与崩岗面积与密度的影响。结果表明:影响崩岗侵蚀的景观格局指数主要由土地利用类型决定,其中林地的景观格局指数对崩岗特征的解释度最高(63.82%),其次为耕地(49.19%)和建设用地(42.01%);耕地景观类型面积、林地聚集度、建设用地景观形状指数和林地斑块连接度4个指标显著影响崩岗特征,对崩岗特征变化的贡献率分别为51.5%、26.9%、9.2%和6.1%,且4个指标对崩岗特征的累积解释度达到66.2%;通径分析发现耕地景观类型面积、林地斑块连接度、林地边缘密度、林地斑块类型面积百分比和建设用地边缘密度的综合作用对崩岗面积变化和密度变化的解释程度分别为71%和85%,其中耕地景观类型面积和林地斑块类型面积百分比对崩岗面积和崩岗密度的影响最大,通径系数分别是0.499、-0.440和0.608、-0.342。总体而言,科学合理的规划耕地、林地和建设用地的空间布局,提升景观类型整体生态效应,对抑制崩岗侵蚀具有重要意义。研究结果对于科学规划土地利用、控制红壤区崩岗侵蚀具有重要指导意义。     

Shoo fly, don't bother me! Efficacy of traditional methods of protecting cattle from tsetse

Studies were made of the efficacy of using smoke and housing to protect cattle from tsetse (Diptera: Glossinidae) in Zimbabwe. The efficacy of smoke was assessed by its effect on catches in Epsilon traps baited with a blend of acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol. The efficacies of different types of kraal (enclosure) were gauged according to the catches of electrocuting targets (E-targets), baited with natural ox odour, placed within various designs of kraal. Smoke from burning wood (Colophospermum mopane) or dried cow dung reduced the catch of traps by approximately 50-90%. Kraals with a continuous wooden or netting wall, 1.5 m high, reduced catches of E-targets by approximately 75%. Arrangements of electric nets were used to assess the numbers of tsetse attacking live cattle within kraals and/or near sources of smoke. The results confirmed findings with traps and E-targets: kraals reduced the numbers of tsetse that fed by approximately 80% and smoke reduced the numbers attracted by approximately 70%; the use of both reduced overall attack rates by approximately 90%. The inclusion of 4-methylguaiacol, a known repellent for tsetse and a natural component of wood smoke, halved the catches of traps and E-targets and the numbers of tsetse attacking cattle. The practical benefits and difficulties of using repellents and/or housing to manage trypanosomiases are discussed.     

Impact of 'living apart together' on postoperative recovery of mice compared with social and individual housing

Social housing is the optimal way of housing female laboratory mice. However, individual housing may be required in experimental designs, for example after surgery. We therefore investigated whether housing two female mice in a cage, separated by a grid partition ('living apart together', LAT), counters the adverse effects of individual housing on postoperative recovery. Ten individually housed (IND) mice, nine socially housed (SOC) mice and nine mice, housed LAT, were surgically implanted with a telemetry transmitter. From one week prior to surgery until three weeks thereafter, several physiological and behavioural parameters were measured in the mice subjected to surgery. The telemetry transmitter measured heart rate (HR), body temperature and activity continuously. Body weight, food and water intake were scored regularly, as were wound healing, ease of handling, nest building and behaviour. Results indicated that SOC mice appear to be less affected by abdominal surgery than IND mice, as indicated by HR and behaviour. LAT, however, did not appear to be beneficiary to the mice. Increased HR levels and differences in behaviour as compared with both SOC and IND animals indicate that LAT may even be the most stressful of the three housing conditions. We therefore conclude that mice benefit most from social housing after surgery. If, however, social housing is not possible, individual housing appears to be a better option than separating mice by a grid partition.     

辽宁黄海海岸交错带的景观变化与设计

辽宁黄海海岸交错带的景观近几十来年变化很快,其中许多景观变化是有意识的人类活动或人工管理形成的景观设计可以看作是已经出现或即将出现的景观变化。由于这一区域海岸交错带有不同的海岸带类型,因而也就有了不同的景观设计方案。     

The relationship between zooplankton community structure and lake characteristics in temperate lakes (Northern Wisconsin, USA)

Zooplankton community structure can be affected by within-lakeand by watershed ecological factors, including water chemistry(related to landscape position), lake morphology and human activityin the watershed. We hypothesized that all three groups of driverswould be correlated with zooplankton species richness and speciescomposition for lakes in northern Wisconsin. Data collectedfrom 52 lakes allowed us to explore the relationship of zooplanktoncommunity structure with ecological drivers. We found that crustaceanzooplankton species richness was not significantly correlatedwith independent environmental variables derived from PCA ordination,nor with measures of community structure based on NMS ordination.However, species composition was correlated with environmentalgradients. Larger zooplankton species (Daphnia pulicaria, Epischuralacustris, Skistodiaptomus oregonensis, Mesocyclops americanus)occurred in large and deep lakes low in the landscape gradient,whereas the smaller species Ceriodaphnia dubia, Daphnia retrocurvaand Leptodiaptomus minutus tended to occur high in the landscape.This shift in species composition was correlated with increasedconductivity, primary productivity and the hypolimnetic refugescharacteristic of larger deeper lakes lower in the landscape.Riparian housing development and littoral zone habitat (measuredas building density and by abundance of logs in littoral zones)were not correlated with zooplankton community structure. Inthese relatively low-impact lakes, natural drivers are stillthe most significant determinants of zooplankton community structure.