干旱沙区生物土壤结皮对红砂种子定居的影响及作用机制

为了探清干旱荒漠区生物土壤结皮对易漂移性植物种子定居影响及作用机制,以巴丹吉林沙漠南缘结皮前期以及藻类、地衣、藓类阶段结皮为场所,通过人工补充种子与野外长期监测的方法对红砂种子在生物结皮上流失动态、种子宿存微区特征以及种子宿存量与微区面积间的关系等进行研究。结果表明：(1)生物土壤结皮发育过程中,地表枯落物、微坑、龟裂缝、长藓的面积百分比均发生了显著变化,即：枯落物呈现出增大(藻类阶段)—稳定不变(地衣阶段)—减小(藓类阶段)的趋势,微坑、龟裂缝均先增大后减小(峰值在地衣阶段),长藓持续增大。(2)4个阶段的种子流失速度或定居率两两之间存在显著差异,流失速度大小依次为：结皮前期>藻类阶段>藓类阶段>地衣阶段,定居率大小为：地衣阶段>藓类阶段>藻类阶段>结皮前期。(3)生物土壤结皮上定居的种子仅宿存于枯落物、微坑、龟裂缝、长藓上,这4种微区上定居种子数与其面积之间均存在显著正相关关系,其关系均可用二次项y=ax²+bx+c(a≠0)表示,等面积微区内的定居种子数大小依次为：龟裂缝>枯落物>微坑>长藓。因此认为,生...     

野放普氏野马(Equus przewalskii)家域面积及其影响因素

采用MCP方法研究了2011年至2012年新疆卡拉麦里山有蹄类自然保护区野放普氏野马家域的变化。通过方差分析验证了年间、季节间不同群体家域及其两两重叠无差异。以家族群大小为协变量进行了野放野马家域协方差分析。利用野放野马家族大小为协变量的协方差分析分析检验了野放野马家族大小与家域关系。结果表明:(1)野马平均家域面积由2011年的(20±2)km~2/匹扩大到2012年的(30±2)km~2/匹。对部分野放群体中头马未发生更替的野马群的研究表明,随着野马群体增大,其家域面积显著增大(P0.05)。(2)单因素方差分析显示,不同野马群的家域面积在不同年份差异显著,且春季家域秋季家域夏季家域。(3)2011年不同群家域两两间相互重叠面积与群大小无显著相关(r=0.256,P=0.5800.05)。而2012年野马群家域两两之间重叠面积有显著差异(F=4.521,df=8,P0.001)。家域两两相互重叠面积与群大小显著相关(r=0.706,P=0.0330.05)。(4)不同季节间野马群家域重叠面积有显著差异(F=5.695,df=8,P0.001)。5号群、7号群和8号群的自身家域重叠面积(P0.05),3号群、6号群和9号群的家域重叠面积(P0.05)。(5)影响野放野马家域面积的生物因子有草本盖度、灌木盖度,非生物因子主要有温度、湿度、风速、最近水源地距离和最近居民点距离等。温度与草本盖度是影响野放野马家域面积大小的主要因素,两者与野放野马家域面积显著相关(P0.01)。     

高原鼠兔家群空间领域的季节性动态格局

为探讨高原鼠兔家群空间领域的季节特征,分别于2005年和2006年的5～8月,在青海省玛沁县,采用标志重捕法和最小多边形面积法对其家群巢区和核域进行了研究.结果表明,不同季节,高原鼠兔巢区和核域面积存在显著差异.5、6月份,成体巢区面积显著大于幼体,但二者核域面积却无显著差异;7月份,成体与第1胎幼体巢区及核域面积均显著大于第2胎.5、6月份雄性成体巢区显著大于7、8月份,6、7月份雌性成体巢区显著大于5月和8月份.巢区及核域面积均与家群个体数呈极显著性正相关关系,说明季节和家群结构均可对高原鼠兔空间领域产生重要作用.     

炔雌醚对内蒙古农牧交错带长爪沙鼠(Meriones unguiculatus)家群大小和巢域行为的影响

为检验施用炔雌醚对农牧交错带长爪沙鼠家群大小与巢域行为的影响,于2006年5月至9月对内蒙古锡林郭勒盟锡林浩特市农牧交错区域分布的长爪沙鼠家群使用炔雌醚进行种群不育控制实验。分设投药区和对照区两个组别,分别于5月、7月与9月份采用1/4样圆面积有效洞口计数法,随机选取24个长爪沙鼠家群,调查对照区域和投药区内沙鼠的家群洞口数量以及家群大小。另在对照区和投药区,随机测定了30个沙鼠的家群活动范围,对比使用炔雌醚前后长爪沙鼠巢域平均半径和活动面积的影响。结果为:对照区家群平均洞口数58个,投药区仅23个,在炔雌醚投药区长爪沙鼠家群受炔雌醚影响,洞口数仅为23个,表明其对长爪沙鼠家群大小控制效果显著。投药区内长爪沙鼠家群密度在投药后连续下降,最大下降幅度较对照区家群密度低70%,表明炔雌醚对长爪沙鼠的家群密度影响较大,可显著降低长爪沙鼠家群密度(P<0.05)。炔雌醚对长爪沙鼠家群平均半径和活动面积的研究结果显示,施用炔雌醚后家群巢域半径与活动面积均显著缩小(P<0.05),与对照区巢域平均面积相比缩小15%、平均活动半径缩小30%。通过以上结果可得出:单独施用炔雌醚对控制野外长爪沙鼠家群以及降低长爪沙鼠巢域、活动面积效果显著。炔雌醚可有效降低农牧交错带长爪沙鼠种群数量和有效活动范围,这对于农牧交错带的鼠害防控,同时降低鼠源性疾病,包括鼠疫的传播都有一定的意义。     

布氏田鼠秋季家群数量与捕食风险的关系

2004年9月25日至10月15日,在内蒙古锡林郭勒盟阿巴嘎旗白音图嘎苏木研究了布氏田鼠(Lasiopodomys brandtii)秋季家群数量与来自艾虎(Mustela eversmanni)的捕食风险。布氏田鼠家群数量调查采用标志重捕法和最小已知存活数估计法(即MNA法)确定,而艾虎对布氏田鼠捕食风险的衡量指标采用在研究期间布氏田鼠洞群区新出现的艾虎粪便和挖掘痕迹。研究区面积4 hm2,涉及91个布氏田鼠家群,658只布氏田鼠,其中,17个布氏田鼠家群有新出现的艾虎粪便,5个家群被艾虎掘开。运用非参数的Mann-Whitney U检验进行数据分析,从艾虎遗留的粪便痕迹来看,未出现艾虎粪便的布氏田鼠家群总秩和为1 096,出现艾虎粪便的田鼠洞群秩和为3 090,统计量U=315,校正Z=﹣3.241,校正P=0.001 2;另外,从艾虎掘开的田鼠家群来分析,没有被艾虎挖掘的布氏田鼠家群秩和为3 757,而被艾虎掘开的田鼠家群秩和为429,统计量U=16,校正Z值为﹣3.514,P=0.000 4。两组差异达到极显著水平,表明艾虎对秋季高数量的布氏田鼠家群具有显著的优先访问和攻击偏好,也意味着高数量的布氏田鼠秋季家群具有更高的被艾虎捕食的风险。     

结直肠癌与肠道微生物群研究进展

肠道微生物群是人体内环境的重要组成部分,与宿主共进化、共代谢、共发育,并与宿主之间相互调控,影响宿主健康。近年研究显示,肠道微生物群参与了结直肠癌的发生和发展。了解肠道微生物群的特征性变化及其诱发结直肠癌的机制对于结直肠癌的防治有着重要意义。目前以肠道微生物群为靶点的干预性基础研究也取得了一些突破性的研究进展。本文主要对结直肠癌患者肠道微生物群的变化、其可能的致病机制及临床相关研究进展等进行综述。     

小兴安岭南坡野猪家域分析

采用笼式活捕野猪,利用无线电遥测技术、R2V、Arcview 和SPSS 软件技术,于2004 年7 月15 日至2006年1 月19 日,对小兴安岭南坡野猪家域进行测定、计算和分析,以了解该地区野猪的家域变化规律。研究结果表明:季节变化影响野猪家域面积,在春、秋季,野猪的家域面积显著大于冬季,而春、夏季间无显著差异;不同性别及年龄野猪家域大小也不同,成体雄性秋季发情期和亚成体春季分窝期家域面积显著增加;在冬、春季家族群野猪的家域面积显著大于独体野猪家域面积,说明家族群对家域面积有影响;亚成体家域大小主要受家族群家域的影响,家族群野猪面积大,相应地家族野猪中亚成体家域面积也大。     

乳蛋白座位与泌乳性状座位连锁关系的研究

本文利用杂合度分析和连锁群分析对乳蛋白基因座位与产奶量及乳成分等数量性状基因间的连锁关系进行了探讨。结果表明,各乳蛋白基因均具有较高的纯合度,但３个酪蛋白基因同时考虑时纯合度较低。泌乳性状的变差对乳蛋白基因座位杂合度没有明显的回归关系。Ｋ－ＣＮ基因与乳脂率和乳蛋白率,α_（ｓ１）－ＣＮ基因与３０５无产奶量间有显著的连锁关系。     

黄土高原生物结皮对地表粗糙度和灌草植物种子二次扩散的影响

生物结皮是黄土高原常见的地表覆被物,在灌草群落下方及植被间空地上广泛发育,深刻影响着灌草植物种子的二次扩散和定居,但目前针对生物结皮对种子二次扩散影响的研究较少,且种子二次扩散的主导因素尚不明确。该研究以风沙土和黄绵土上的生物结皮(藻结皮和藓结皮)为对象,以无结皮为对照,利用倾斜摄影测量法测定了地表粗糙度,并通过风力扩散实验测定地表粗糙度对6种不同形态灌草植物种子的移位率、损失率和扩散距离的影响,继而结合Spearman相关性分析,研究灌草种子在生物结皮表面扩散的主导因素。研究结果表明:(1)与无结皮相比,风沙土藻结皮和藓结皮的地表粗糙度分别增加了6.69倍和6.13倍,黄绵土上分别增加了2.52倍和1.45倍。(2)风沙土上,干燥条件下的地表粗糙度比湿润条件下增加了26.56%,而在黄绵土上则降低了9.42%。(3)在干燥条件下,风沙土生物结皮的地表粗糙度比黄绵土上增加了16.84%,湿润条件下则降低了16.38%。(4)风沙土上,种子在生物结皮表面的移位率、损失率和扩散距离分别比无结皮降低了77.1%、95.4%和72.2%,在黄绵土上则分别降低了76.5%、93.8%和66.8%...     

中国典型人工林净初级生产力与林龄的关系撤回

人工林在陆地生态系统中起着重要的碳汇作用。本研究基于我国25个研究区的5个主要造林树种(刺槐、栓皮栎、杉木、樟子松和油松)的树木年轮数据,利用各研究区不同树种的生物量方程计算标准木的年均净初级生产力(NPP)进而扩展到林分尺度,利用InTEC模型及Law模型模拟各研究区不同人工林NPP与林龄的关系。结果表明：刺槐林、杉木林和油松林NPP随林龄表现出先增加后逐渐平稳的趋势,栓皮栎林和樟子松林NPP达到峰值后则出现下降的趋势。不同人工林NPP-林龄拟合曲线出现拐点的顺序为：樟子松林11年、杉木林14年、油松林16年、刺槐林20年。其拐点NPP分别为6.65、7.58、4.70和2.59 t·hm^-2·a^-1。InTEC及Law NPP-林龄模型在大尺度范围内都有较高的拟合精度,樟子松林InTEC模型R²最低(R²=0.95),均方根误差(RMSE)为0.55 t·hm^-2·a^-1;杉木林InTEC模型R²最高(R²=...     

Seasonal home range use by Japanese monkeys in the snowy Shiga heights

Between December 1974 and November 1975 (157 days), it was found that seasonal home range changes in the Shiga C troop were closely related to food changes, vegetation, and the existence of neighbouring troops. The detailed points clarified may be summarized as follows: (1) The seasonal home range sizes from winter to autumn were 1.23 km², 1.46 km², 1.69 km², and 1.21 km², respectively, and the annual size was 3.66 km²; (2) The food changed from bark and buds of trees in winter to young leaves and stems of grasses and trees in spring and summer, and fruits in autumn; (3) Each home range clearly changed according to the phenology of the plants used as food at each season; (4) The food abundance for the monkeys was extremely poor in winter, relatively poor in summer, plentiful in spring, and the best in autumn; and (5) The Shiga C troop and the neighbouring Shiga B₂ troop overlap in their home ranges in spring and autumn, but are separated during winter and summer.     

Troop Size,Habitat Use,and Diet of Chacma Baboons (<Emphasis Type="Italic">Papio hamadryas ursinus</Emphasis>) in Commercial Pine Plantations: Implications for Management

Primates living outside protected areas frequently come into conflict with humans. While the focus of most research has been on the costs and consequences of crop raiding in relation to subsistence agriculture, large-scale commercial agriculture presents conservation challenges of its own. Baboons that occupy commercial pine plantations in southern Africa often damage young trees and, consequently, are shot in large numbers. We here aim to describe the population structure and resource and habitat use by baboons in such areas to provide the data needed for the formulation of viable long-term conservation policies. We used radio-collars to obtain estimates of home range size and habitat usage from 2 plantation troops and detailed observation of 1 of these to determine their diet. We compared these data, together with counts of troop size, to those from individuals in the same population that did not enter plantation. Although the mean troop size (42.2) of baboons in plantations was significantly higher than in adjoining natural areas (18.3), population density (2.8 individuals/km²) did not differ. Plantation baboons had a comparatively restricted diet in which a few indigenous species were disproportionately represented. Pine cambium was not an important dietary component and the baboons generally avoided compartments of pine trees to forage in small pockets of various natural plant communities. We argue that foresters should shift their policy from one of baboon extirpation to the long-term management of local populations, in the context of a proper and ongoing evaluation of the discounted cost of baboon damage.     

The Spatial Ecology of Chacma Baboons (<Emphasis Type="Italic">Papio ursinus</Emphasis>) in a Human-modified Environment

Anthropogenic habitat alteration can have a dramatic effect on the spatial distribution and ranging patterns of primates. We characterized the spatial ecology of a free-living troop of chacma baboons (Papio ursinus) in a human-modified environment in the Cape Peninsula, South Africa. We used GPS and behavioral observations collected over 1 yr to quantify the troop’s home range size, habitat selection, choice of sleeping site, and foraging patterns. The troop comprised 115 individuals living in a home range of 9.50 km², giving a density of 12.1 baboons/km². Area use correlates positively with exotic vegetation and negatively with indigenous vegetation and altitude. The troop spent significantly more time in low-lying human-modified environments, i.e., plantations, vineyards, and urban habitat, than in indigenous vegetation that was largely restricted to steeper slopes at higher elevations. The troop slept exclusively in exotic trees, 94% of which were located in the plantation, 3% in urban habitat, and 3% in vineyards. The most consumed food items were exotic grasses, subterranean food items, and exotic pine nuts. The survival and persistence of the focal troop in close proximity to the urban edge while ≥3 neighboring troops were previously extirpated suggests that access to low-lying land in conjunction with a land-use practice that does not preclude baboon presence has been fundamental to both their survival and persistence at such a high density. The almost exclusive use of exotic vegetation both as a food source and as a safe refuge for sleeping highlights the ecological flexibility of baboons, but the systematic loss of low-lying productive land poses the single greatest threat to their continued persistence on the Cape Peninsula.     

Radio tracking of a male Japanese macaque emigrated from its group

A male Japanese macaque's ranging behavior before and after emigration from its group was investigated by using radiotelemetry techniques. The male's locations before leaving the troop were regarded as those of the troop, while those after leaving were regarded as those of a solitary male. Monthly home range sizes of the male with the troop were larger than those of the male moving alone, while the whole home range of the male with the troop for three months was much smaller than that of the male moving alone for five months. Overlaps between the male's home ranges with the troop between months were much greater than those between the ranges of the male moving alone. One neighboring troop's home range overlapped the male's range in August and September, and another neighboring troop's range overlapped the male's in October. The mean travel distance and speed of the male with the troop per day did not differ significantly from those of the male moving alone. The results suggest that emigrated males of Japanese macaques may visit home ranges of some troops and stay for a while without interacting troop monkeys before they decide to visit or join the troops.     

Population structure,demography, and dynamics of mountain baboons: An interim report

Counts of 61 baboon troops (Papio cynocephalus ursinus) at four localities in the Drakensberg mountains confirmed earlier reports of a small mean troop size. This troop size of 22.49 animals changed neither with latitude nor elevation. Data from two of the sites suggested that population density increases from south to north, while a working assumption of 2.5 animals/ km² allowed us to set the population size at 7,540 animals, living in 335 troops. Both the adult sex ratio of 2.07 females/male and the immature/ adult female ratio of 1.17 were unaffected by troop size. Repeated counts from nine known troops revealed that the population is at equilibrium. © 1995 Wiley-Liss, Inc.     

Population organization of wild pig-tailed macaques (Macaca nemestrina nemestrina) in West Sumatra

A field study on wild pig-tailed macaques was conducted in West Sumatra, Indonesia, during three periods from January 1985 to February 1987. During the nine months of the first two periods, unprovisioned monkeys were traced and observed. During the eight months of the last period, monkeys were provisioned and observed mainly at baiting sites. Three troops and ten solitary males appeared at the two baiting sites. Some males immigrated into and emigrated from the troops. The troops had a multi-male multi-female composition. The size of the various troops was 74, 49, and 81 individuals, respectively, and the mean adult sex ratio in the troops was 1:6.3; that is, markedly biased towards females. The home ranges of two of the troops overlapped considerably. When the troops encountered each other at the baiting sites, a clear dominance relationship was recognized. The troops differed in their integration as ranging units: two of the troops did not form subgroups (temporary fission and fusion of each troop), while the other troop frequently split into subgroups. Recent field studies on pig-tailed macaques have suggested a multi-leveled society with harem-type unit groups. However, in the present study, the troops observed had neither a substructure similar to harem-type groups nor a superstructure that emerged as a result of fusion of the troops. The unit group of the pig-tailed macaques appears to be a multi-male, matrilineal group.     

Female Defensibility in a Small Troops of Japanese Macaques vis-à-vis Nontroop Males and Copulation on the Periphery of the Troop

I provide data compiled over 4 yr on the mating behavior in small troops of wild Japanese macaques on Yakushima Island. The key parameters are the number of sexually receptive females, the number of nontroop males (NTMs), and copulation on the periphery of the troop. I analyzed the following aspects: 1) changes in the proportion of copulation with high-ranking males (HRMs) and NTMs, 2) variations in factors such as fluctuation in the number of sexually receptive females and troop males and their effects on the number of visiting NTMs, 3) the effect of attempted interruption of mounting series by other males, and 4) some aspects of copulation on the periphery of the troop. Throughout the study, 56% of the total number of females mated most frequently with the α-male in a single mating season. However, the relative mating success of HRMs varied over the years and between individuals. The number of visiting NTMs varied depending on the number of receptive females and troop males. Females tended to mate with the NTMs when they appeared around their troops. The direct effect of interruption of the mounting series by other males is equivocal. The females mated with the low-ranking males (LRMs) and NTMs on the periphery of the troop, which increased the possibility of mounting series ending with ejaculation. Females actively sought opportunities for copulation on the periphery of the troop by moving there or initiating close proximity with LRMs and NTMs there. On Yakushima Island, the mating success of HRMs was not always as high as that predicted by the priority of access model. The injury status of the HRM, the number of visiting NTMs, and female choice are all considered to influence a male’s mating success.     

Troop size and human-modified habitat affect the ranging patterns of a chacma baboon population in the cape peninsula, South Africa

Differences in group size and habitat use are frequently used to explain the extensive variability in ranging patterns found across the primate order. However, with few exceptions, our understanding of primate ranging patterns stems from studies of single groups and both intra- and inter-specific meta-analyses. Studies with many groups and those that incorporate whole populations are rare but important for testing socioecological theory in primates. We quantify the ranging patterns of nine chacma baboon troops in a single population and use Spearman rank correlations and generalized linear mixed models to analyze the effects of troop size and human-modified habitat (a proxy for good quality habitat) on home range size, density (individuals/km(2) ), and daily path length. Intrapopulation variation in home range sizes (1.5-37.7 km(2) ), densities (1.3-12.1 baboons/km(2) ), and daily path lengths (1.80-6.61 km) was so vast that values were comparable to those of baboons inhabiting the climatic extremes of their current distribution. Both troop size and human-modified habitat had an effect on ranging patterns. Larger troops had larger home ranges and longer daily path lengths, while troops that spent more time in human-modified habitat had shorter daily path lengths. We found no effect of human-modified habitat on home range size or density. These results held when we controlled for the effects of both a single large outlier troop living exclusively in human-modified habitat and baboon monitors on our spatial variables. Our findings confirm the ability of baboons, as behaviorally adaptable dietary generalists, to not only survive but also to thrive in human-modified habitats with adjustments to their ranging patterns in accordance with current theory. Our findings also caution that studies focused on only a small sample of groups within a population of adaptable and generalist primate species may underestimate the variability in their respective localities.     

The use of plants as regular food in ancient subarctic economies: a case study based on Sami use of Scots pine innerbark

This study combines ethnological, historical, and dendroecological data from areas north of the Arctic Circle to analyze cultural aspects of Sami use of Scots pine (Pinus sylvestris L.) inner bark as regular food. Bark was peeled in June when trees were at the peak of sapping, leaving a strip of undamaged cambium so the tree survived. As a result, it is possible to date bark-peeling episodes using dendrochronology. The paper argues that the use of Scots pine inner bark reflects Sami religious beliefs, ethical concerns, and concepts of time, all expressed in the process of peeling the bark. A well-developed terminology and a set of specially designed tools reveal the technology involved in bark peeling. Consistent patterns with respect to the direction and size of peeling scars found across the region demonstrate common values and standards. Peeling direction patterns and ceremonial meals relating to bark probably reflect ritual practices connected to the sun deity, Biejvve.     

Death of vigorous trees benefits bark beetles

Bark beetles (Coleoptera: Scolytidae) are commonly associated with live host trees that are stressed, a relationship that has been attributed to lower host defenses or greater nutritional quality of these trees. However, most bark beetle species commonly inhabit freshly dead trees where induced host defenses are absent. In this study, we investigate the role of tree vigor at the time of death for pine engraver bark beetles, Ips pini (Say), breeding in freshly dead jack pine, Pinus banksiana Lamb. As indices of tree vigor, we considered tree size, phloem thickness, and several measures of recent growth rate (last year's growth increment, mean annual increment and basal area increment in the past 5 and 10 years, and periodic growth ratio). We examined the relationship between these indices in three stands, aged 60, 77, and 126 years, and found that phloem thickness, previously shown to have a strong positive effect on bark beetle reproduction, was only weakly associated with tree growth rate and inconsistently related to tree size among the three stands. To examine the effects of tree vigor on pine engraver reproduction, we felled 20 trees of various sizes from the 77-year-old stand, and experimentally established breeding males and females in 25-cm-long sections. Offspring were collected and characteristics of breeding galleries were measured. Using stepwise regression, we consistently found that indices associated with tree growth rate best explained beetle reproductive performance, as they were positively related to parental male and female establishment on logs, female reproductive success, length of egg galleries, proportion of eggs resulting in emerged offspring, and negatively related to the length of the post-egg gallery. Surprisingly, phloem thickness had no unique effect on pine engraver reproduction, except for a weak negative effect on the establishment success of parental females. The strong effect of tree vigor observed in this study suggests that substantial mortality of vigorous trees, such as caused by windthrow, can contribute to significant increases in bark beetle populations that could trigger outbreaks in living trees. Received: 3 February 1999 / Accepted: 27 April 1999