旅游干扰对喀纳斯自然保护区植物群落的影响

研究不同强度旅游干扰对喀纳斯自然保护区西伯利亚云杉(Picea obovata)林、草甸群落和金露梅(Potentilla fruticosa)灌丛的群落物种组成、物种多样性以及土壤理化性质的影响.结果表明:(1)在不同强度干扰下,云杉林中灌木层与草本层物种组成存在较大差别,随着干扰强度的增大,群落物种多样性呈先上升后下降的变化;(2)草甸群落Shannon-Wiener多样性指数随干扰强度的增大有下降趋势,土壤理化性质也受到了影响;(3)围栏内外两个金露梅灌丛群落在不同的干扰强度下,群落优势度和均匀度具有显著差异(P<0.05),土壤理化性质也存在显著差异.土壤理化性质的改变在一定程度上也改变了群落的物种多样性.     

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.     

Indicators of the Ecological Impact of Bottom-Trawl Disturbance on Seabed Communities

The Ecosystem Approach to Fisheries requires that managers take account of the environmental impacts of fishing. We develop linked state and pressure indicators that show the impact of bottom-trawling on benthic communities. The state indicator measures the proportion of an area where benthic invertebrate biomass (B) or production (P) is more than 90% of pristine benthic biomass (B _0.9) or production (P_0.9). The pressure indicator measures the proportion of the area where trawling frequency is sufficiently high to prevent reaching predicted B_0.9 or P_0.9. Time to recovery to B_0.9 and P_0.9 after trawling, depending on the habitat, was estimated using a validated size-based model of the benthic community. Based on trawling intensity in 2003, 53.5% of the southern North Sea was trawled too frequently for biomass to reach B_0.9, and 27.1% was trawled too frequently for production to reach P_0.9. As a result of bottom-trawling in 2003, in 56% of the southern North Sea benthic biomass was below B_0.9, whereas in 27% of the southern North Sea benthic production was below P_0.9. Modeled recovery times were comparable to literature estimates (2.5 to more than 6 years). The advantages of using the area with an ecological impact of trawling as a pressure indicator are that it is conceptually easy to understand, it responds quickly to changes in management action, it can be implemented at a relevant scale for fisheries management, and the necessary effort distribution data are centrally collected. One of this approach’s greatest utilities, therefore, will be to communicate to policy makers and fishing enterprises the expected medium- to long-term ecological benefits that will accrue if the frequency of trawling in particular parts of fishing grounds is reduced.     

Ecological characterization of a tropical myxomycete assemblage--Maquipucuna Cloud Forest Reserve, Ecuador

The assemblage of myxomycetes (plasmodial slime molds) associated with cloud forests of the Maquipucuna Cloud Forest Reserve in the western Andes was investigated. Within three study sites located along a gradient extending from 1200 to 2700 m above sea level, a clear pattern of decreasing myxomycete diversity and productivity with elevation was apparent. As such, these data conform to the pattern of "reverse diversity" for myxomycetes in the neotropics, with higher diversity for less mesic forest types than for more mesic forest types. Canonical correspondence analysis of myxomycete abundances in relation to microhabitat parameters revealed three major ecological assemblages: wood-, litter- and inflorescence-inhabiting species. All three assemblages include a number of specialized species, with the assemblage associated with litter being the most diverse and the one associated with inflorescences being the most distinctive. In addition, samples from the microhabitat represented by the cover of epiphyllic liverworts on living leaves regularly produce myxomycetes in moist chamber culture but with few sporocarps and no evidence of any specialized species. At least near ground level, bark-inhabiting (corticolous) myxomycetes are uncommon in the cloud forests sampled in the present study.     

广东同乐大山自然保护区蕨类植物生态分布研究

在掌握蕨类植物基本组成的基础上,对广东同乐大山自然保护区蕨类植物的生态特性及生态分布进行详细分析,结果表明该区蕨类植物生态分布具有以下特征:(1)古老蕨类植物分布广泛;(2)蕨类植物垂直分布较明显;(3)林下植被中蕨类植物优势显著;(4)国家重点保护蕨类植物分布多;(5)蕨类植物敏感指示性强。     

Past Anomalies as a Diagnostic Tool for Evaluating Multiple Marine Ecological Disturbance Events

In the search for the best ecological and economic indicators of ecosystem change, a unifying solution for joining data from disparate fields appears as a general rule: Organize data into space/time/topic hierarchies that permit convergence of data resulting from shared and appropriate scaling. The scale of the data selects for compatible methodologies, leading to data integration and the discovery of new relationships. Information technology approaches include bibliographic keyword searches, data-mining, data-modeling and geographic information system design. The approach was used within the “HEED” (Health Ecological and Economic Dimensions) study, which reconstructed historic marine disturbance events within the Northwestern Atlantic, Gulf of Mexico and Caribbean Sea. The object of the study was to retrospectively derive co-occurring Multiple Marine Ecological Disturbances (MMEDs). Disturbances include indices of morbidity, mortality and disease events affecting humans, marine invertebrates, flora, and wildlife populations. Correlations between space/time occurrence, event coincidence, climate and oceanographic forcing are used to better define multiple marine ecological disturbance types. Systematic derivation of these types is part of diagnostic approach that can assist or guide marine ecological risk assessment.     

仔鳗生态失调死亡率与肠道微生态系重调整的研究

本文报告,在1989年4月至1991年3月,为考察长江仔鳗资源的开发利用,对仔鳗生态失调死亡率及其防治方法做了一些研究。结果表明,仔鳗溯河性生态失调死亡率为49.8％(可信限为46.3～53.3％);寒冷性生态失调死亡率为48.59％(可信限为43.5～53.5％)。在实验中,应用肝浆(含B族维生素),在早期喂给仔鳗治疗有效(u=2.17>1.96,p<0.05);含抗生素食物喂给无显著性效果。应用由鳗鲡成鱼和黑斑泥鳅体内分离的肠微球菌、贝内克菌和非O-I群弧菌,喂给仔鳗进行肠道微生态系重调整(readjutment of intestinal microecosystem),对提高仔鳗生理功能适应性和降低生态失调死亡率有满意效果(u=2.84>2.58,p<0.01)。     

神农架金丝猴的生态学观察

金丝猴(Rhinopithecus roxellanae)仅产于我国,属国家Ⅰ级保护动物,自然分布于四川、陕西、甘肃的部分地区和湖北省神农架自然保护区。1983年以来,笔者对神农架金丝猴生存环境生态习性等作了长期观察研究,结果报道如下。     

鹞落坪自然保护区大型真菌的生态分布

为了解及合理开发大型真菌资源,调查了安徽省鹞落坪国家级自然保护区大型真菌的种类组成及生态分布。结果表明:该区大型真菌资源丰富,在食用、药用和营林等方面具有很好的开发前景。     

带有干扰和非线性指标的脉冲时滞SI模型的渐近性质(英文)

研究了一个带有干扰和非线性指标的脉冲时滞SI模型,通过引入三个引理,获得该疾病最终灭绝和保持持久的充分性条件。结果表明,时滞因素对该模型的全局吸引性和持久性都有影响。此外。如果脉冲免疫接种率的最大值和最小值之比大于某一阈值,则该疾病最终灭绝,本文的主要特点是将多时滞和变系数引入脉冲SI模型,数值模拟表明,该系统具有复杂的动力学行为,包括周期解和周期振荡.     

Disturbance governs dominance of an invasive forb in a temporary wetland

Dominance of invasive species is often assumed to be due to a superior ability to acquire resources. However, dominance in plant communities can arise through multiple interacting mechanisms, including disturbance. Inter-specific competition can be strongly affected by abiotic conditions, which can determine the outcome of competitive interactions. We evaluated competition and disturbance as mechanisms governing dominance of Phyla canescens (hereafter lippia), an invasive perennial forb from South America, in Paspalum distichum (perennial grass, hereafter water couch) meadows in floodplain wetlands of eastern Australia. Water couch meadows (in the study area) are listed under the Ramsar Convention due to their significance as habitat for migratory waterbirds. In the field, we monitored patterns of vegetation boundaries between the two species in response to flooding. Under controlled glasshouse conditions, we explored competitive interactions between the native water couch and lippia subject to different soil moisture/inundation regimes. We did this using a pairwise factorial glasshouse experiment that manipulated neighbor density (9 treatments) and soil moisture/inundation (4 treatments). In the field trial, inundation increased the cover of water couch. Under more controlled conditions, the invader had a competitive effect on the native species only under dry soil conditions, and was strongly inhibited by inundation. This suggests that dry conditions favor the growth of the invader and wetter (more historical) conditions favor the native grass. In this system, invader dominance is governed by altered disturbance regimes which give the invader a competitive advantage over the native species.     

山西芦芽山自然保护区山麻雀的生态资料

2000～2003年的4～10月在山西芦芽山国家级自然保护区,对山麻雀的生态进行了观察。结果表明,山麻雀在本区最早迁来为5月4日,最晚迁离为9月24日;繁殖前每公里遇见数为0．64只,繁殖后每公里遇见数0．79只。最早营巢期为6月1日,最早产卵期为6月9日,窝卵数4～6枚,最早孵化期为6月13日,孵化期12～13天,孵化率为84．44％;巢内育雏期为13～14天,巢外育雏期为8～9天,幼鸟成活率为86．84％,繁殖力为2．11只。食物中动物性食物占75．43％,植物性食物占24．60％。     

厦门国家级自然保护区白鹭生态安全评价

白鹭的生态安全是指白鹭所处的生态系统能够维持白鹭种群持续生存的需求和条件,其中关键是白鹭生境的安全。白鹭生境安全从根本上取决于生境的适宜性和人为对生境的干扰程度,又可以理解为生境受到人类干扰后所能保持的生态适宜性。分别选择白鹭在厦门的2个主要繁殖栖息生境——大屿岛和鸡屿岛和10个代表性觅食生境为研究对象,对白鹭生境的生态适宜性和人为干扰程度进行分别评价。其中,生境适宜性评价采用指标体系法,通过赋值、计算进行评价;人为干扰程度评价主要依靠地理信息系统分析方法,将人为干扰程度用不同土地利用形式代表,利用Mapiafo7．0和ArcView3．2a地理信息分析软件对白鹭生境的人为干扰程度进行计算评价。最后,结合生境适宜性评价和人为干扰程度评价结果,对厦门自然保护区白鹭的生态安全进行综合评价。评价结果显示：鸡屿岛和大屿岛作为白鹭在厦门的繁殖栖息地的生态安全程度均处于安全等级,鸡屿岛的生态安全程度高于大屿岛。厦门白鹭的觅食生境总体来看处于较安全等级,但没有一处觅食地是属于安全等级。     

庞泉沟自然保护区原麝的生态研究

原麝(Moschus moschiferus)又名香獐子,獐子、麝狗子等,属国家二级保护动物,分布于我国东北和华北等地区。雄麝有麝香腺,能分泌麝香,其经济价值很高,在国际市     

西双版纳勐养自然保护区生境格局研究

使用ARC/INFO和ARC/VIEW地理信息系统 ,对以 1 995年 3月的卫星影像图、相关图件及数据为基础的图形数据库进行迭加分析 ,研究了西双版纳勐养自然保护区的生境格局 .结果表明 :1 )生境格局不是所有生态因素图件的简单迭加 ,以年均温和年降水量为主导因素 ,以自然植被为可见指标研制了生境格局 ;2 )确定出 3种生境类型的 2 0个生境个体 :热带季节雨林生境 (2 37.53km2 ,占总面积的 2 1 % )、热带山地雨林生境(1 2 6 .93km2 ,占 1 1 % )和亚热带季风常绿阔叶林生境 (764 .88km2 ,占 68% ) ;3)初步建立了一个山地生境格局的研究体系 :生态小区→生境类型→生境组分 ;4)生境格局研究揭示了保护区 59%的现有重点保护对象 (热带雨林 )不在核心区的现实 ,为保护区功能区调整提供了科学依据 .     

The Effect of Digestive Capacity on the Intake Rate of Toxic and Non-Toxic Prey in an Ecological Context

Digestive capacity often limits food intake rate in animals. Many species can flexibly adjust digestive organ mass, enabling them to increase intake rate in times of increased energy requirement and/or scarcity of high-quality prey. However, some prey species are defended by secondary compounds, thereby forcing a toxin limitation on the forager’s intake rate, a constraint that potentially cannot be alleviated by enlarging digestive capacity. Hence, physiological flexibility may have a differential effect on intake of different prey types, and consequently on dietary preferences. We tested this effect in red knots (Calidris canutus canutus), medium-sized migratory shorebirds that feed on hard-shelled, usually mollusc, prey. Because they ingest their prey whole and crush the shell in their gizzard, the intake rate of red knots is generally constrained by digestive capacity. However, one of their main prey, the bivalve Loripes lucinalis, imposes a toxin constraint due to its symbiosis with sulphide-oxidizing bacteria. We manipulated gizzard sizes of red knots through prolonged exposure to hard-shelled or soft foods. We then measured maximum intake rates of toxic Loripes versus a non-toxic bivalve, Dosinia isocardia. We found that intake of Dosinia exponentially increased with gizzard mass, confirming earlier results with non-toxic prey, whereas intake of Loripes was independent of gizzard mass. Using linear programming, we show that this leads to markedly different expected diet preferences in red knots that try to maximize energy intake rate with a small versus a large gizzard. Intra- and inter-individual variation in digestive capacity is found in many animal species. Hence, the here proposed functional link with individual differences in foraging decisions may be general. We emphasize the potential relevance of individual variation in physiology when studying trophic interactions.     

云南哀牢山国家级自然保护区蕨类植物生态地理研究

报道了哀牢山国家级自然保护区蕨类区系有蕨类植物48科、118属、446种(包括变种和变型)。从蕨类植物的垂直分布、东西分布和生态类型的划分等几个方面对哀牢山国家级自然保护区蕨类植物生态进行探讨并得出以下结论:(1)在海拔分布上,蕨类植物有着与不同植被相关的生态适应性,2000~2800 m的中山湿性常绿阔叶林和山顶苔藓矮林地带蕨类植物种类最为丰富,附生蕨类植物占到了该海拔地带蕨类植物总种数的28.5%;(2)东坡有蕨类植物387种,西坡则只有355种,东西坡共有种达295种;(3)哀牢山国家级自然保护区蕨类植物可划分为16个生态类型,本区明显地以阴生植物、亚高温植物和中生植物居多,附生植物种类所占比例大,旱生植物和石生植物种类少等为主要生态特征。哀牢山国家级自然保护区蕨类植物的温度生态类型以亚热带植物种类为主,温带植物和寒温带植物少。     

Contagious Disturbance, Ecological Memory, and the Emergence of Landscape Pattern

Landscapes are strongly shaped by the degree of interaction between pattern and process. This paper examines how ecological memory, the degree to which an ecological process is shaped by its past modifications of a landscape, influences landscape dynamics. I use a simulation model to examine how ecological memory shapes the landscape dynamics produced by the interaction of vegetative regrowth and fire. The model illustrated that increased ecological memory increased the strength and spatial extent of landscape pattern. The extent of these changes depended upon the relative rates of vegetative recovery and fire initiation. When ecological memory is strong, landscape pattern is persistent; pattern tends to be maintained rather than destroyed by fire. The generality of the simulation model suggests that these results may also apply to disturbance processes other than fire. The existence of ecological memory in ecosystems may allow processes to produce ecological pattern that can entrain other ecosystem variables. The methods presented in this paper to analyze pattern in model ecosystems could be used to detect such pattern in actual ecosystems. Received 14 November 2000; accepted 21 September 2001.     

交通设施对可可西里藏羚季节性迁移的影响

本文基于对可可西里自然保护区内藏羚跨越青藏公路及青藏铁路的监测结果,初步探讨了公路及铁路对藏羚季节性迁移的影响。观测结果显示,目前对藏羚迁移的主要干扰因素为：交通设施自身的屏障作用、人为活动、公路交通流量、未清理施工现场及未恢复植被等。本文通过对野生动物通道的使用情况监测和对不同通道形式的使用评价,为未来铁路建设和野生动物通道的优化提供了科学依据。