人工林赤腹松鼠危害与繁殖关系的初步研究

2000年4月至2003年12月,通过固定样地长期监测及样地外标本采集,对洪雅县人工林赤腹松鼠危害与繁殖的关系进行了初步研究,以期为人工林赤腹松鼠危害机理研究和危害控制提供科学依据.研究结果表明,洪雅县赤腹松鼠年均危害率呈上升趋势,但时空变化较大.危害全年都可能发生,但主要发生在3～5月,4月最严重.从赤腹松鼠繁殖情况看,雌鼠主要在3～4月和7～8月繁殖,4月繁殖指数最高;雄鼠基本全年都有睾丸下垂,即处在繁殖期.赤腹松鼠春季的危害高峰期和繁殖高峰期一致,繁殖期赤腹松鼠对食物能量和巢材的需求是产生春季危害高峰的主要原因.     

赤腹松鼠在人工林中的危害特征

2008年3月～2009年3月,设置15个固定样地每月监测,对四川省洪雅县柳杉Crypotomeria fortunei和杉木Cunninghami lanceolata人工混交林中赤腹松鼠Callosciurus erythraeus的危害特征进行调查研究,结果表明:1) 2～7月是危害的主要时期,其中3、4月最高;柳杉的年平均危害株率高于杉木,但两者的年平均危害程度区别不大;2)不同龄林的危害情况不同,月平均危害株率:中林显著高于成林和幼林(P<0.05);月平均危害程度:幼林高于中林,中林高于成林,三者差异显著(P<0.05);3)林木被危害的部位主要集中在上部和中部;不同龄林危害部位的分布不同,成林和中林的危害部位比例为上部>中部>下部,而幼林是中部>上部>下部;4)啃剥树皮类型以包含木栓、木栓形成层和次生韧皮部的树皮为主,同时有少数外周皮;啃剥外周皮的现象出现在2～4月和7～11月.     

毒饵站防治赤腹松鼠危害效果研究

为防治赤腹松鼠对人工林的危害,进行了利用喉管状聚氯乙烯(PVC)软管制作的毒饵站防治赤腹松鼠危害效果的研究。研究设4个防治样地(每公顷分别安装4个和8个毒饵站,毒饵站中投放有效成分为0.005%的溴敌隆大米毒饵)和1个对照样地,对照样地每公顷安装8个毒饵站(投无毒大米饵料)。毒饵投放于2014年3月初进行,投放毒饵后,4—7月、9月和12月调查防治样地和对照样地中的新增危害数、投放在毒饵站中的无毒饵料取食情况和赤腹松鼠个体数等指标的变化情况,评估防治效果。结果显示:毒饵投放后的4月份,4个防治样地内新危害分别下降90.00%、85.71%、93.75%、77.78%,与对照样地间的差异有统计学意义;4个防治样地内无毒饵料取食率分别下降83.33%、91.30%、97.18%、94.83%,与对照样地间的差异有统计学意义;在防治样地内,无论是无毒饵料的取食率,还是新增危害数,均长期保持较低水平。此外,毒饵投放后的4月份,防治样地内可见赤腹松鼠个体数下降83.33%。整个实验过程中没有发现非靶动物和二次中毒现象发生。据实验结果,结合溴敌隆大米毒饵的毒饵站防治赤腹松鼠效果好。在洪雅人工林场,推荐每公顷安装4个毒饵站;防治时间以每年3月初为宜,1年防治1次即可有效减少赤腹松鼠种群数量和降低危害。     

利用毒饵站防治赤腹松鼠危害的可行性研究

赤腹松鼠剥食树皮的行为常给人工林造成严重危害。因赤腹松鼠在树上活动,防治难度较大,为此进行了在树上放置毒饵站防治其危害的可行性研究。2012年9月~2013年7月,为选择合适的毒饵站类型,对毒饵站的材料、口径和放置高度进行了实验;并调查了赤腹松鼠对毒饵站中饵料取食的季节性变化,评估玉米和大米在不同季节作为饵料防治危害的可行性。研究结果显示,毒饵站的材料(塑料喉管和竹筒)以及在树上的放置高度(0.8 m和1.8 m)对赤腹松鼠的取食无影响,但赤腹松鼠对口径较大(90 mm)的毒饵站的访问显著高于对口径较小(80 mm)的毒饵站的访问。赤腹松鼠对饵料的访问结果显示:赤腹松鼠对玉米的取食率在秋季达到最高32.40%,最低时为夏季8.44%;对大米的取食率在春季达到了最高29.38%,最低时为冬季8.33%。根据实验结果,认为在各个季节利用毒饵站法防治赤腹松鼠的危害都是可行的,可根据具体的防治时间选择玉米或大米作为饵料。此外,赤腹松鼠对大颗粒的玉米饵料的访问显著高于对小颗粒的玉米饵料的访问。在实验过程中通过红外线摄像机采集到的4120张图片和830段视频显示超过99%的饵料均是赤腹松鼠取食的,极少有非靶动物访问毒饵站。赤腹松鼠对饵料的访问行为表现出了晨昏双高峰的特点。     

赤腹松鼠（Callosciurus erythralus）春季生境特征初步分析

2009年2月至5月,在广西龙江河畔对赤腹松鼠（C.erythralus）的春季生境特征进行了分析.野外共测量了57个10m×10m样方中的13个生态因子,并运用频次分析和主成分分析的方法,对赤腹松鼠的春季生境选择因子进行了分析.结果表明,赤腹松鼠春季生境的主要特征为：郁闭度良好,水源距离＜30m,坡度20～40°,避风性良好,坡向以东坡和南坡为主,坡位中坡位或上坡位,食物因子良好,人为干扰距离＜10m,海拔50～100m,乔木密度＜50株,乔木距离低于4m,灌木密度低于200株,灌木距离＜2m.影响赤腹松鼠春季生境选择的主要因子为郁闭度、避风性、坡度、坡位和灌木距离;次要因子为海拔、人为干扰距离、乔木距离、水源距离、乔木密度、灌木密度、食物丰富度、坡向.     

赤腹松鼠防治指标研究

通过调查洪雅林场不同年龄柳杉林赤腹松鼠危害情况,测量各年龄段被害木与健康木的生长差异,计算出单株材积损失率,用回归拟合危害程度与单株材积损失率的关系,计算当地柳杉经济允许损失水平和防治指标。结果表明:材积损失率与危害等级均成正相关。赤腹松鼠危害造成的材积损失率随着树龄略有差异,10~12年、13~15年生柳杉林的经济允许材积损失率分别为2.411%和2.742%,对应的新危害指数(∑(各危害级株数×危害等级)/(调查株数×危害最高级)×100%)为2.42和2.92。     

四川洪雅县赤腹松鼠的食性观察

2008年1月至2010年8月,在主要树种为柳杉Cryptomeria fortunei的四川省洪雅县林场中,采用直接观察和胃容物分析法对赤腹松鼠Callosciurus erythraeus食性进行研究.发现赤腹松鼠取食的植物共有14科23种,如小柱悬钩子Rubus columellaris和板栗Castanea mollissima的果实,油茶Camellia oleifera的花及柳杉和杉木Cunninghamia lanceolata的树皮.结合往年文献,已知确认洪雅县赤腹松鼠取食的植物共28种.根据胃容物分析,果实种子的比例为秋季(75.60％±0.53％)＞夏季(63.32％±0.69％)＞冬季(34.02％±0.43％)＞春季(14.35％±0.71％),差异显著(P＜0.05);而树皮在夏季和秋季分别为7.32％±0.50％和8.30％±0.87％,显著低于冬季和春季的28.13％±0.72％和28.71％ ±0.84％ (P ＜0.05).根据结果分析,赤腹松鼠的主要食物是植物的果实种子,在冬春取食较多的树皮可能与果实种子短缺有关.     

赤腹松鼠（Callosciurus erythraeus）对林木剥皮危害的初步研究

浙江省被松鼠剥皮危害的树木有马尾松、杉木、柳杉、湿地松、银杏等计47种,以针叶树最严重。危害林木的主要种类为赤腹松鼠嘉兴亚种(Callosciurus erythraeus styani)。据1987—1989年在759块标准样地12947株树木调查,平均被害率为54.44％,被害树木中死亡的占13.3％。 松鼠剥食树皮从秋季开始,以2—3月最严重,这与此时松鼠食物供应不足有关。松鼠剥皮危害程度也与林分组合有关,混交林较单纯林受害率低。此外与食物供需丰歉也有关系。     

人工林赤腹松鼠春夏季活动节律与行为特征观察

2009年3～8月,通过观察和运用无线电遥测对四川洪雅县人工林赤腹松鼠活动节律和行为特征进行了研究.结果 显示,赤腹松鼠为昼行型动物,其春夏活动节律呈晨昏双高峰型.春夏季雄性赤腹松鼠日活动时间分别为5.00 h/d±1.39 h/d(占日长的39.62%)和7.54 h/d±1.20 h/d(占日长的55.12%),雌性夏季日活动时间为6.48 h/d±0.98 h/d,占日长的46.82%.雄性赤腹松鼠春季活动强度为37.38%±8.75%,夏季雌雄性活动强度分别为46.30%±7.04%和53.85%±8.60%.雄性赤腹松鼠春夏季之间以及夏季雌雄之间的日活动时间和活动强度均存在显著差异.赤腹松鼠清晨出巢及傍晚回巢时间与日出日落显著正相关.春夏季赤腹松鼠的行为以取食为主,占日活动行为时间分配的比例分别为86.23%和79.54%.赤腹松鼠的活动节律和活动时间办受天气状况、日照时间等因素的影响.     

赤腹松鼠一新亚种

在查对中国南部赤腹松鼠标本(401号)的基础上,发现分布于云南东北部昭通地区的赤腹松鼠与赤腹松鼠其他亚种有明显的区别.毛色特征:背部棕黄色,背中央区域稍带黑色;腹部至前胸栗红色;喉、颏部棕灰色;尾毛背腹无明显差异,尾毛末端棕黄、次末端黑,尾末端具棕黄色(稍黄白)区域;前后足背棕褐色,稍带黑色.进一步对头骨可量性状数据进行分析(差异系数),结果表明:分布于该地区的赤腹松鼠分别与赤腹松鼠其他13个亚种两两之间至少有一项差异系数大于1.28,系一新亚种Callosciurus erythraeus zhaotongensis subsp.nov..     

洪雅县人工林赤腹松鼠活动范围及栖息地利用

2009年3～8月期间,通过观察并利用无线电遥测等方法对洪雅县林场赤腹松鼠(Callosciurus erythraeus)的活动范围和栖息地利用进行了研究。研究结果显示,赤腹松鼠的最小凸多边形(minimum convex polygon,MCP)巢域面积为(1.90±0.59)hm2,95%和60%固定核法(fixed kernel,FK)巢域面积分别为(1.06±0.19)hm2和(0.16±0.03)hm2。处在求偶高峰期的雄鼠会显著地扩大活动范围。栖息地利用的研究结果表明,赤腹松鼠对栖息地因子有明显的选择性,倾向在坡度大、灌木生长繁茂、靠近人居和水源及有藤本植物覆盖的区域活动。     

Restoring Forest Raptors: Influence of Human Disturbance and Forest Condition on Northern Goshawks

The Northern Goshawk (Accipiter gentilis) occurs throughout the Holarctic region in wooded environments. Changes in food supply and breeding habitat, along with human encroachment into otherwise suitable habitat, have negatively impacted the goshawk in some regions. Thus, conservation of the species requires coordinated planning to restore and manage both habitat and human activities in goshawk territories. Using our work in the Sierra Nevada (Lake Tahoe Basin) as a case study, we investigated why territories were abandoned and identified actions needed to reverse conditions negatively impacting goshawks that should lead to more successful goshawk conservation worldwide. We summarized all nesting records available on the goshawk in the Basin, quantified human activity levels within and near frequently and infrequently occupied territories, and described the forest structure and species composition of territories and related these parameters to goshawk territory occupancy. As we hypothesized, reproductive success was higher within frequently occupied territories. Human activity was twice as high within infrequently as compared to frequently occupied territories. There was a greater extent of all types of roads and trails within the infrequently occupied territories. Our findings, along with results from Europe, suggest that goshawk protection has been insufficient in some regions and actions that will reduce anthropogenic disturbance should be initiated, including reducing and re‐routing human activity, and reducing the extent of roads and trails within territories. We provide guidance on how to prioritize territories for restoration.     

商洛山区人工油松群落物种多样性与环境因子关系研究

在陕西省商洛山区人工油松群落分布集中的地段设置16个样地,对其分布的乔木、灌木和草本植物进行了调查,并对样地附近土壤理化指标进行了测定;采用α多样性指数对研究区域的物种多样性进行测度,并分析了12个环境因子与3个物种多样性指数的关系。结果表明:(1)研究区群落样地共记录植物48科84属95种,油松林下灌草组成丰富,分布较广的物种有木兰科、菊科、蔷薇科、百合科和莎草科,群落Shannon-Wiener多样性指数计算结果与Margalef丰富度指数、Pielou均匀度指数的变化趋势基本一致。(2)群落Margalef丰富度指数与年龄的二项式回归达显著水平(P=0.023 7)、与20～40cm土壤速效N含量的二项式回归达极显著水平(P=0.003 3);Pielou均匀度指数与0～20cm土壤pH值二项式回归达显著水平(P=0.014 4);Shannon-Wiener多样性指数与标准化坡向的直线回归达显著水平(P=0.049 6)、与40～60cm土壤pH值的二项式回归达显著水平(P=0.029 0)。研究表明,该群落物种多样性主要受年龄、土壤速效N、坡向、以及土壤pH值影响。     

The Importance of Hunting and Habitat in Determining the Abundance of Tropical Forest Species in Equatorial Guinea

Understanding the impact of hunting on wildlife populations is crucial to achieving sustainability and requires knowledge of prey abundance responses to different levels of exploitation. While the abundance of primates has been shown to respond independently to hunting and habitat, habitat is rarely considered simultaneously when evaluating the impacts of hunting. Furthermore, the importance of these two factors in determining the abundance of other species has not been well investigated. We evaluate the independent effects of hunting and habitat on the abundance of a diverse assemblage of species, using a series of predictions and data from a study in Equatorial Guinea. Line transect surveys in sites of varying hunting intensity and habitat, and weekly interviews with hunters on current hunting effort in each site, were conducted. We also consider the role of past hunting, and discuss the interrelationships between hunting and habitat variables. We show that for primates, hunting is important in determining abundance, while for rodents and duikers, habitat is more important. Our findings show that the effects of hunting and habitat on abundance vary greatly between species, are often confounded and require an approach that isolates their independent effects to determine the true impact of hunting. Conservation managers must consider and incorporate habitat heterogeneity when managing hunting systems, taking into account the way in which the relative importance of these factors can vary between species.     

Interaction of Press and Pulse Disturbance on Crayfish Populations: Flood Impacts in Pasture and Forest Streams

Interactions between press and pulse disturbances can significantly impact benthic macroinvertebrate (crayfish) populations. Press disturbances such as land-use change can make crayfish more vulnerable to the detrimental effects of pulse disturbances, by changing the habitats available to crayfish. The impact of a pulse disturbance, a major flood (1 in 28 years return period), on crayfish (Paranephrops planifrons) was significantly greater in pasture than native forest streams. Population densities of crayfish in three forest and three pasture streams had been measured seasonally for 2 years prior to the flood and many crayfish had been marked with individually identifiable tags. Low numbers of marked crayfish were recaptured after the flood in the forest streams, but no marked crayfish were identified in any pasture stream. Crayfish densities in one pasture stream declined from an average of 5 m^–2 prior to the flood to <1 m^–2 soon after the flood and it took 3 years for the population to show evidence of recovery. Macrophytes and cobbles, the dominant habitats of crayfish in pasture streams, did not appear to provide stable refugia during the flood. Habitat stability was linked to the riparian zone in forest streams where undercut banks, tree roots, and pools were important habitats for crayfish. Frequent pulse disturbance could affect population persistence of refugia-dependent species when the pressure of land-use change affects the stability of habitats, but this may only be evident over long time scales.     

岛屿栖息地鸟类群落的丰富度及其影响因子

1997年1月至1997年12月间,以杭州市的园林鸟类群落为研究对象,对岛屿栖息地鸟类群落的丰富度与面积,人为干扰,内部结构和周围景观结构等多种因素的关系进行了系统的分析和检验。在杭州市各园林中共观察到82种鸟类。园林单次调查的鸟类物种数（S）与园林全年总物种数（Sy)与园林面积（A）的最佳回归拟合方程分别为;S＝ 2.7432A^0.3846,Sy=10.6574A^0.3669。杭州市园林鸟类群落物种－面积关系的成因不支持平衡假说,随机取样假说,栖息地多样性假说和干扰假说,岛屿栖息地鸟类群落的丰富度是多因素综合作用的结果,包括取样面积效应（排除了取样面积效应之后,小园林具有更高的物种密度）,栖息地结构的多样性（其中树种多样性是最主要的影响因子）,干扰因素,物种因素和研究尺度等几个方面。     

城市公园中赤腹松鼠的家域特征及昼间活动规律初探

2015年12月至2016年5月,对上海动物园内活动的9只赤腹松鼠进行无线电遥测,应用Homing法进行空间定位,基于最小凸多边形（MCP）和95%固定 核空间（95%Kernel）模型估算城市绿地中赤腹松鼠的家域面积、空间分布特征及个体间的重叠情况,同时记录赤腹松鼠的昼间行为规律。赤腹松鼠 家域面积平均值为12376（MCP）~18146 m²（95%Kernel）,雌雄个体间家域面积无显著差异（Independent-sample test,t= -0.101,P=0.922）。 赤腹松鼠冬季家域面积与春季家域面积间无显著差异（One way ANOVA,MCP：F=3.900,P=0.070;95%FK：F=3.566,P=0.081）。部分赤腹松鼠家域 间存在重叠,冬季重叠指数0.36~0.63,春季重叠指数0.02~0.43。赤腹松鼠的昼间行为以移动（29.4%）、取食（25.1%）和休息行为（24.7%）为主 。在不同季节,赤腹松鼠的取食行为发生显著变化（One way ANOVA,F=119.268,P<0.001）,冬季取食行为发生频率最高（33.3%）,夏季最低 （16.4%）;领域行为在夏（15.8%）、秋（16.2%）季发生频率较高,春季（5.8%）降低（One way ANOVA,F=140.416,P<0.001）。赤腹松鼠昼间 活动呈“U”型分布,主要集中于05:00—08:00和15:00—18:00,休息主要分布于12:00—13:00。     

Ecological Restoration and Large-Scale Ecological Disturbance: The Effects of Drought on the Response by Fish to a Habitat Restoration Experiment

Human‐induced erosion regularly delivers massive quantities of fine sediments into streams and rivers forming large static bodies of sediment known as sand slugs, which smother in‐stream habitat, alter community structure, and decrease biodiversity. Sand slugs are widespread in parts of southeastern Australia as well as in many other parts of the world, and there is now considerable interest in restoring such affected streams. The reintroduction of large timber is widely suggested as a strategy for restoring habitat complexity, but this has rarely been tested in sand slug–affected streams. We examined the response of fish populations to wood addition to two streams in southeastern Australia that have been impacted by sand slugs. Manipulated sites (three per treatment) had either one or four timber structures added, and these sites were compared with (three) unmanipulated (control) sites before and after the manipulation occurred. Despite a supraseasonal drought during the study, we observed short‐term increases in the abundance of Mountain galaxias (Galaxias olidus) at the four‐structure sites, while both the four‐structure and the one‐structure treatments appeared to buffer against drought‐induced declines in two other species, River blackfish (Gadopsis marmoratus) and Southern pygmy perch (Nannoperca australis), relative to controls. However, drought eventually caused the complete loss of surface water from these streams and the loss of fish from both manipulated and unmanipulated sites. Thus, although the study supports the use of timber structures as a means of increasing local fish abundances, these beneficial effects were, in these streams, contingent upon permanency of flow. Because sedimentation has depleted the number of permanent refuge pools in these creeks, recovery rates of the fauna (i.e., resilience) are likely to be slow. We therefore conclude that in streams subjected to frequent disturbance, restoring refugia may be as, if not more, important as restoring what we term residential habitat.     

Habitat selection by Eurasian lynx (Lynx lynx) is primarily driven by avoidance of human activity during day and prey availability during night

The greatest threat to the protected Eurasian lynx (Lynx lynx) in Central Europe is human‐induced mortality. As the availability of lynx prey often peaks in human‐modified areas, lynx have to balance successful prey hunting with the risk of encounters with humans. We hypothesized that lynx minimize this risk by adjusting habitat choices to the phases of the day and over seasons. We predicted that (1) due to avoidance of human‐dominated areas during daytime, lynx range use is higher at nighttime, that (2) prey availability drives lynx habitat selection at night, whereas high cover, terrain inaccessibility, and distance to human infrastructure drive habitat selection during the day, and that (3) habitat selection also differs between seasons, with altitude being a dominant factor in winter. To test these hypotheses, we analyzed telemetry data (GPS, VHF) of 10 lynx in the Bohemian Forest Ecosystem (Germany, Czech Republic) between 2005 and 2013 using generalized additive mixed models and considering various predictor variables. Night ranges exceeded day ranges by more than 10%. At night, lynx selected open habitats, such as meadows, which are associated with high ungulate abundance. By contrast, during the day, lynx selected habitats offering dense understorey cover and rugged terrain away from human infrastructure. In summer, land‐cover type greatly shaped lynx habitats, whereas in winter, lynx selected lower altitudes. We concluded that open habitats need to be considered for more realistic habitat models and contribute to future management and conservation (habitat suitability, carrying capacity) of Eurasian lynx in Central Europe.