Seasonal variation of diet and time budget of Eastern hoolock gibbons (Hoolock leuconedys) living in a northern montane forest

Most gibbons dwell in the tropical forests of Southeastern Asia, but eastern hoolock gibbons (Hoolock leuconedys) survive in high montane forest ranging from 1,600 to 2,700 m a.s.l. in Gaoligongshan (>24°30′N), Yunnan, China. To assess the behavioral adaptations of hoolock gibbons to the montane forest, we related temperature and food availability within the habitat to the seasonal behavioral patterns of a family group and a solitary female between August 2010 and September 2011 in Nankang, Gaoligongshan National Nature Reserve. The maximum temperature was 29.2 °C and the minimum temperature was ?0.3 °C during the period. The monthly mean temperature was <10 °C between December and February, making Nankang the coldest gibbon habitat reported so far. Nonfig fruit and fig availability declined to nearly zero in cold months. The family group increased resting and decreased travel and social behaviors when the monthly mean temperature was low. Compared with other gibbon populations, the hoolock gibbons spent proportionally less time feeding on figs and other fruit than other gibbon populations except Nomascus concolor and Symphalangus syndactylus. Only 36 species of plants provided nonfig fruit or figs, which is less than the number of fruit species consumed by any other gibbon population observed during a similar period of time (about 1 year). Hoolock gibbons shifted their diet to leaves and increased feeding time when fruit was not available. We conclude that diet flexibility and an energy-conserving strategy during the cold season when fruit is scarce have enabled the hoolock gibbons to survive in a northern montane forest.     

高黎贡山赧亢白眉长臂猿春季栖息地利用

2006年3月24日—5月6日,在高黎贡山赧亢片区共设置利用样地与可利用样地各30个,跟踪观察白眉长臂猿栖息地利用行为。定性因子分析表明,白眉长臂猿偏爱在东坡(Ei=0.344)活动,可能与其能提供避风的温暖微生境有关;偏爱栓皮栎(Ei=0.455)和拟樱叶柃(Ei=0.068)等乔木,可能是由于这些树种的树冠面积大,可为白眉长臂猿提供连续的移动路线和大的活动空间。定量因子分析表明,利用和可利用样地中共有12个因子(坡度,乔木和竹平均高度,乔木平均胸围,乔木和灌木盖度,乔木、竹和藤本密度,距水源、道路和草果地距离)存在显著差异,说明白眉长臂猿对栖境的空间结构具有高度的选择性。判别分析结果显示,坡度、乔木平均胸围、竹密度、距水源距离和乔木平均高度是判别利用和可利用样地的关键因子,即为影响其生境利用的主要因子,判别正确率为98.3%。作为树栖灵长类,具有一定基面积的连续乔木[高度(14.14±3.19)m,胸围(90.72±26.12)cm]树冠层是白眉长臂猿的适宜生境;较大的坡度(39.98±8.10°)减少了来自地面的干扰;而竹林是白眉长臂猿春季重要的取食地。     

高黎贡山大塘白眉长臂猿春季栖息地利用及与赧亢的比较

2007年3月9日～4月7日调查了高黎贡山大塘片区白眉长臂猿的生境利用情况.对1雌1雄 (均为成体) 家群和1只雌性独猿跟踪观察.设置利用样地和对照样地各30个,测量了4个定性因子和19个定量因子.判别分析结果显示,在大塘影响白眉长臂猿春季生境利用的关键因子是藤本密度和坡度2个因子;影响赧亢与大塘白眉长臂猿的则是距空旷地距离、竹子平均高度和距水源距离等3个因子.据地形因子分析结果,大塘和赧亢的白眉长臂猿对避风和趋阳坡有共同需求.比较两地白眉长臂猿对与植被结构有关的8个生态因子的利用结果提示,赧亢适宜白眉长臂猿栖息的生境呈破碎化分布,而大塘的植被均匀性和完整性较高.两地白眉长臂猿对优势乔木的选择都具有相同的外貌形态特征,树形高大、树冠连续、郁闭度高的乔木可为它们提供更多的移动路线、更广的活动空间和更好的隐蔽条件.白眉长臂猿对两个分布区林下竹灌层选择差异的原因一方面是人为干扰强度不同所致,另一方面是对林下竹灌层的利用方式不同.藤本是白眉长臂猿在乔木层与竹灌层之间活动的主要交通媒介和连接纽带.人为干扰强度的不同亦是导致两地白眉长臂猿生境利用差异的重要原因之一.     

云南高黎贡山自然保护区白眉长臂猿种群及数量现状初报

经2003~2006年访问和现场调查,表明白眉长臂猿在高黎贡山自然保护区约有15~20群,25~40只。它们主要分布在中山湿性常绿阔叶林。栖息环境的急剧恶化和人类猎捕是造成白眉长臂猿数量下降的两个主要原因。提出应加强白眉长臂猿的栖息地保护和消除生境隔离,加强公众保护宣传教育和加强白眉长臂猿的生态生物学等基础研究。     

Ranging behavior of eastern hoolock gibbon (Hoolock leuconedys) in a northern montane forest in Gaoligongshan,Yunnan, China

Generally, food abundance and distribution exert important influence on primate ranging behavior. Hoolock gibbons (genus Hoolock) live in lowland and montane forests in India, Bangladesh, Myanmar and China. All information about hoolock gibbons comes from studies on western hoolock gibbons (Hoolock hoolock) living in lowland forest. Between August 2010 and September 2011, we studied the ranging behavior of one habituated group of eastern hoolock gibbon (H. leuconedys) living in a seasonal montane forest in Gaoligongshan, Yunnan, China. Results show that the study group did not increase foraging effort, calculated in this study as the daily path length, when fruit was less available. Instead, the gibbons fed more on leaves and decreased traveling to conserve energy. They relied heavily on a single food species in most study months which was patchily distributed within their total (14-month) home range, and during most months they used only a small portion of their total home range. In order to find enough food, the group shifted its monthly home range according to the seasonal availability of food species. To satisfy their annual food requirements, they occupied a total home range of 93 ha. The absence of neighboring groups of gibbons and the presence of tsaoko cardamom (Amomum tsaoko) plantations may also have influenced the ranging behavior of the group. Further long-term studies of neighboring groups living in intact forests are required to assess these effects.     

Population dynamics of hoolock gibbons (Hylobates hoolock) in Assam,India

Data are presented on group size, composition, and reproduction of several hoolock gibbon groups studied in different areas of Assam, India, between 1986 and 1988. Presence of fewer young than reported in earlier studies signals a grim future for these gibbons unless strict conservation measures are undertaken.     

Effects of tsaoko (Fructus tsaoko) cultivating on tree diversity and canopy structure in the habitats of eastern hoolock gibbon (Hoolock leuconedys)

In this study, the quadrat method was used to study the effects of tsaoko(Fructus tsaoko) plantation on tree diversity and canopy structure of two natural habitats of eastern hoolock gibbon(Hoolock leuconedys): Nankang(characterized by extensive tsaoko plantation) and Banchang(relatively well reserved and without tsaoko plantation). Totally, 102 tree species from 25 families and 16 woody liana species from 10 families were recorded in Nankang, whereas 108 tree species from 30 families and 17 woody liana species from 12 families were recorded in Banchang. Although the tree species between two habitats is different, both habitats are characterized by enriched food resources for eastern hoolock gibbons, sharing similar dominant plant families. Due to tsaoko plantation, tree density proportion and diversity of forest layerⅠ(20 m) in Nankang were both significantly decreased, but the tree density of layerⅡ(10-20 m) increased. Likewise, in conjunction with these behavioral observations, we also address potential impacts of tsaoko plantation on the behavior of eastern hoolock gibbon.     

Pollen representivity of montane forest taxa in south-west Uganda

Results presented in this paper demonstrate the relationship between two data sets from Mubwindi Swamp, south-west Uganda. The first data set is from a survey of dryland montane forest within the immediate catchment and the second is in the form of pollen spectra recovered from surface samples of sediment. Numerical analysis grouped pollen types encountered into five categories, according to their level of representivity when compared with abundances of the same taxa in the sampled vegetation: under representative, moderately under representative, representative, moderately over representative, and over representative. The northern part of Mubwindi Swamp also yielded a 5-m-long sequence of organic-rich sediments (core MB6) from which sub-fossil pollen and radiocarbon data have been previously obtained. This provides an opportunity to apply calibration factors derived from modern pollen–vegetation relationships to sub-fossil pollen data that were obtained from the same site. These calibration factors effectively down-weighted the influence of over representative pollen types and permitted the discrimination of a phase of forest disturbance that had not previously been so clearly visible in sub- fossil pollen data.     

云南澜沧地区热带山地雨林的群落学特征研究

在2500m2的固定样地上,共计有维管束植物100～105种,分属于45～47科、70～74属;胸径≥2cm的树种丰富度为69～74,ShannonWiener指数为3.5954～3.6267,Pielou均匀度指数为0.8426～0.8491。群落植物区系成分可分为10个类型,以热带区系成分为主,占83.17%～84.69%,其中又以泛热带和热带亚洲(印度-马来西亚)分布成分占优势,分别占33.67%～36.63%和24.75%～26.53%。群落以高位芽植物为主,其中又以中、小高位芽植物占优势,分别占50.00%～52.78%和22.12%～22.22%;在叶片生态学特征上,群落以中叶(66.67%～75%)、单叶(83.65%～85.19%)、纸质(61.11%～65.38%)、全缘(72.12%～72.22%)、非尾尖(86.11%～88.48%)为主。与西双版纳季节雨林相比,澜沧地区热带山地雨林体现出明显地向季风常绿阔叶林的过渡特征,如区系组成中的热带成分偏低而温带成分偏高,大高位芽植物以及大叶、复叶、全缘叶比例较低,而小高位芽植物以及小叶、单叶、非全缘叶比例较高。     

Disrupted montane forest recovery hinders biodiversity conservation in the tropical Andes

Aim

Andean montane forests are biodiversity hotspots and large carbon stores and they provide numerous ecosystem services. Following land abandonment after centuries of forest clearing for agriculture in the Andes, there is an opportunity for forest recovery. Field-based studies show that forests do not always recover. However, large-scale and long-term knowledge of recovery dynamics of Andean forests remains scarce. This paper analyses tropical montane forest recovery trajectories over a 15-year time frame at the landscape and tropical Andean scale to inform restoration planning.

Methods

We first detect “potential recovery” as areas that have experienced a forest transition between 2000 and 2005. Then, we use Landsat time series analysis of the normalized difference water index (NDWI) to classify four “realized recovery” trajectories (“ongoing”, “arrested”, “disrupted” and “no recovery”) based on a sequential pattern of 5-yearly Z-score anomalies for 2005–2020. We compare these results against an analysis of change in tree cover to validate against other datasets.

Results

Across the tropical Andes, we detected a potential recovery area of 274 km² over the period. Despite increases in tree cover, most areas of the Andes remained in early successional states (10–25% tree cover), and NDWI levelled out after 5–10 years. Of all potential forest recovery areas, 22% showed “ongoing recovery”, 61% showed either “disrupted” or “arrested recovery”, and 17% showed “no recovery”. Our method captured forest recovery dynamics in a Peruvian arrested succession context and in landscape-scale tree-planting efforts in Ecuador.

Main conclusions

Forest recovery across the Andes is mostly disrupted, arrested or unsuccessful, with consequences for biodiversity recovery and provision of ecosystem services. Low-recovery areas identified in this study might be good candidates for active restoration interventions in this UN Decade on Restoration. Future studies could determine restoration strategies and priorities and suggest management strategies at a local planning scale across key regions in the biodiversity hotspot.     

西双版纳热带山地雨林群落乔木树种多样性研究

根据块样地资料对西双版纳热带山地雨林树种多样性特征进行了分析.结果表明,在2 500m²的样地上,随着起测胸径递增,各样地乔木个体数和树种丰富度均表现为依次递减;低海拔带上(850～1000 m)的山地雨林(1、2号样地)的各指数值无一定变化规律,较高海拔带上(1200～2000 m)的山地雨林(3～6号样地)的Shannon-Wiener指数和Simpson指数均表现为依次递减,而Pielou均匀度指数则呈依次递增的趋势.较高海拔带上的山地雨林在较小乔木起测胸径(≥2 cm、≥5 cm、≥10 cm)的树种丰富度、多样性和均匀度指数均要明显大于低海拔带上的山地雨林,而两者在较大乔木起测胸径(≥20 cm、≥30 cm、≥50 cm)的各指数值无明显差异.随着取样面积的递增,各样地树种丰富度、多样性和均匀度指数在取样面积递增到2 000m²处均已趋于平缓.     

海南五指山热带山地雨林植物物种多样性研究

王指山热带山地雨林的物种种类十分丰富,在１ｈｍ＾２样地中共出现５４个科,１００个属的乔木树种１７７种,１３３７个个体。区系地理分析表明属的分布区类型以热带分布型成分占优,为８９．０％,充分体现了五指山山地雨林的热带性质。多样性指数分析结果为：样地１Ｍａｒｇａｌｅｆ指数１７．８２２,Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ指数５．６２１,均匀度０．８２３,Ｓｉｍｐｓｏｎ指数０．０５０,均匀度６．７７５,表明五指     

西双版纳热带山地常绿阔叶林蕨类植物的组成及生态特征

根据4个50m×50m样地(400个5m×5m小样方,共计1hm2取样面积)的详细调查及对各样地外蕨类植物区系的采集调查,研究了西双版纳热带山地常绿阔叶林蕨类组成特点及其数量特征等。结果表明:在所调查的5hm2滇南热带山地常绿阔叶林里记录有蕨类植物64种;在生活型组成上,以地面芽和地下芽为主;在叶特征上,以革质和纸质叶居多,叶形以一回羽状和二回羽状叶占优势;在森林群落中蕨类植物有明显的季相变化;在重要值上,狗脊、疏叶蹄盖蕨、苏铁蕨、光叶鳞盖蕨、清秀复叶耳蕨和假稀羽鳞毛蕨的重要值之和占重要值总和的84.02%,其中,狗脊的重要值占重要值总和的1/3以上,它们是该森林群落中占优势的蕨类种类,在生态分布上为该森林群落的"适宜种";研究还发现,勐腊凤尾蕨为该森林群落的确限种。     

Gap-phase regeneration in a tropical montane forest: the effects of gap structure and bamboo species

To study the influence of gap structure and bamboo species on the regrowth of montane Atlantic forest, colonization by plants was characterized in 30 treefall gaps (30.3–500.5 m²). The study was conducted at Santa Virgínia (45°30 W, 23°17 S), a 4970-ha reserve of Atlantic montane forest in southeastern Brazil. Area covered by bamboos ranged from 0% to 100% of gap area. Average height of surrounding canopies ranged from 12 to 30 m. As gap are covered by bamboo and average height of surrounding canopies increased, both density and richness of pioneer woody species decreased. Density and richness of shade-tolerant species were negatively influenced by gap area. Low-light-demanding species of Miconia, Leandra and Rapanea accounted for the majority of both pioneer species and individuals sampled, whereas high-light demanding pioneers of Cecropia, Alchornea and Tibouchina were poorly represented. We suggest that in the Atlantic montane forest bamboo species compete for gaps, excluding other light-demanding pioneers. This results in an overall reduction of pioneer species richness in the Atlantic forest.     

高黎贡山赧亢白眉长臂猿春季食物选择

2007年3月9日—4月28日,在高黎贡山赧亢跟踪观察白眉长臂猿(Hoolock hoolock)的春季食性及取食行为,将其行为分为食果、食果汁和食叶。采用瞬时扫描法记录白眉长臂猿的取食行为,取食的种类、部位和地点等。在其活动区域内,以取食树为中心设置20m×20m的利用样方和以随机方式设置同样大小的可利用样方各19个。在样方内收集与取食树及食物资源相关的6个因子的数据。统计食物种类和资源量、选择指数、取食点的选择性等。结果表明,赧亢白眉长臂猿春季取食的食物共10种,其中果实类植物3种,果汁类植物1种,嫩叶类植物6种。10种食物中,白眉长臂猿对印度木荷(Schima khasiana)的果实和缅甸木莲(Maglietia haokeri)的嫩叶呈弱选择,对其他8种食物资源均呈强选择。Mann-WhitneyU-检验结果表明,利用样方和可利用样方间的食物资源量及食物种类数均差异极显著,以利用样方的资源量大,每一样方食物种类较多。果实是赧亢白眉长臂猿春季的主要食物资源,而嫩叶是补充。呈强选择的食物并不一定是取食频次高的食物;反之,取食频次高的食物也不一定呈强选择。白眉长臂猿常选择易处理的果实和粗灰分含量少的嫩叶,且果实是它摄取水分的主要来源。白眉长臂猿通常选择食物资源和种类相对集中的区域取食,这可以减少动物因寻找食物所耗费的能量,同时获得多种食物,满足其生理对营养的需求。     

Hydraulic architecture and water use of selected species from a lower montane forest in Panama

 Plant water relations of nine woody species were studied in a lower montane rain forest in Panama. These data provide a partial test of the hypothesis that hydraulic architecture of lower montane species might limit transpiration and thus leaf size or nutrient transport (as suggested by J. Cavelier and E. G. Leigh, respectively). Diurnal variation in leaf transpiration was closely correlated with changes in net radiation. Peak transpiration rates (7 × 10^–5 kg s^–1 m^–2) were as high as peak transpiration rates from tropical lowland forests but mean daily water use [0.39 ± 0.08 (SEM) kg m^–2 day^–1] were mostly lower than comparable data from tropical lowland forests. Thus transpiration rates are sufficiently high for sufficiently long periods to make it unlikely that nutrient transport is limited by transpiration. Another objective of this study was a comparison of two different methods to measure hydraulic conductance (K_h = flow rate per unit pressure gradient) and leaf specific conductance of stem segments (K_L = K_h/leaf area distal to the segment). The results obtained with the traditional conductivity apparatus and the high pressure flow meter method, yielded similar results in six out of seven cases. Received: 20 March / Accepted: 21 October 1997     

西双版纳热带山地常绿阔叶林蕨类植物多样性研究

基于4个50m×50m(包含400个5m×5m)样方调查,统计了蕨类植物的α多样性指数、优势度指数、相似性指数及β多样性指数。结果表明:在调查的1hm2西双版纳热带山地常绿阔叶林里,蕨类植物的物种丰富度为32种;不同样地蕨类植物丰富度指数、多样性指数、优势度指数及均匀度指数的变化趋势一致;该森林群落蕨类植物的物种多样性虽然不高,但优势种群显著;通过3个无人为干扰与1个受人为干扰样地的对比分析研究看出,该类森林遭受一定程度的人为干扰后,蕨类植物物种丰富度、多样性、优势度及相似性等均显著下降,其中物种多样性的降低尤为显著,既使群落的外貌、结构等恢复至接近原始林状态,蕨类植物丰富度及多样性也难以恢复,故此,保护原始的森林植被是保护该森林蕨类植物多样性的有效措施之一。