Spatio-temporal growth dynamics of a subAlpine Pinus uncinata stand in the French Alps

Natural forests are characterised by a high level of both spatial and temporal heterogeneity. The major processes involved in the creation and maintenance of forest heterogeneity in temperate climates are small-sized canopy disturbances. The resulting openings also modify the growth conditions for the remaining trees. The analysis of tree growth responses using dendrochronological techniques allows the reconstruction of the time sequence of the disturbances. The radial growth analysis is coupled here with both a spatial analysis and a demographic analysis of the forest structure. The age classes are temporally organised in cohorts and spatially distributed in spatial aggregates. The analysis of the most documented disturbance event allowed us to determine the size of the disturbance response patch (between 0.036 and 0.073 ha) and the duration of the disturbance (six years). We considered that this small-scale disturbance event may have been caused by the fall of a single tree and has freed the surrounding trees of its competition.     

Seasonal Variation in the Activity Patterns and Time Budgets of <Emphasis Type="Italic">Trachypithecus francoisi</Emphasis> in the Nonggang Nature Reserve,China

Activity patterns and time budgets are 2 important aspects of animal behavior that researchers use to investigate ecological influences on individual behavior. We collected data on activity patterns and time budgets in 1 group of François’ langurs (Trachypithecus francoisi) from August 2003 to July 2004 in the Nonggang Nature Reserve, Guangxi Province, China, via instantaneous scan sampling method with 15-min intervals. The diurnal activity pattern of François’ langurs showed morning and afternoon feeding peaks, with a midday resting peak. Seasonal change was apparent in the activity pattern: 2 significant feeding peaks occurred in the dry season and only 1 significant feeding peak in the rainy season. The group spent an average of 51.5% of the daytime resting. Feeding and moving accounted on average for 23.1% and 17.3% of the activity budget, respectively. Subjects spent little time on social activities, averaging 2% for grooming and 5.5% for playing. Their time budgets showed significant seasonal variation: they spent a greater proportion of time on feeding and less time on resting and grooming in the dry season than in the rainy season. They also differed among different sex-age classes: immatures spent more time playing, whereas adults devoted more time to resting, feeding, and grooming. Correlations between time budgets and food items or food availability clearly indicated that François’ langurs might adopt an energy-maximizing strategy when preferred foods were scarce in the dry season.     

Changes in forest structure, species diversity and spatial pattern following hurricane disturbance in a Piedmont North Carolina forest, USA

Aims: Large hurricanes have profound impacts on temperate forests,but owing to their infrequent nature these effects have rarelybeen examined in detail. In 1996, Hurricane Fran significantlydamaged many long-term tree census plots in the Duke Foreston the North Carolina Piedmont, thereby providing an exceptionalopportunity to examine pre- and post-hurricane forest compositionaltrajectories. Our goal was to examine immediate, short-term(0–4 years) and longer term (5 year) hurricane-inducedstructural, spatial and compositional changes in the tree population(stem d.b.h > 1 cm) in the context of our detailed, long-termknowledge of the dynamics of these forests. Methods: We surveyed stem damage and tree mortality in 34 long-term permanentplots (ca. 70-year record; 404–1 012 m²) and 7 large mappedtree stands (ca. 20-year record; 5 250–65 000 m²) representingboth transition-phase, even-aged pine stands and uneven-agedupland hardwood forests. We employed three types of damage measuresto quantify stand-level damage severity: percentage of stemsdamaged, percentage of basal area lost and a ‘stand-leveldamage index’. Second-order spatial analysis (Ripley'sK-function) was used to investigate patterns in tree mortality. Important findings: Our study found hurricane effects on the structural attributesof Piedmont forests to be variable and patchy. Changes in treespecies composition, however, were modest. Uprooting was themajor damage type for the overstory trees [diameter at breastheight (d.b.h.) >10 cm] apparently due to the exposure ofthe crowns to high wind combined with heavy rainfall prior toand during the storm. Saplings, juvenile trees and small trees(1–10 cm d.b.h.) of the understory and midstory were mainlydamaged by being pinned or bent by their damaged large neighbors.Hurricane-induced tree mortality varied weakly among species,was positively correlated with pre-hurricane tree size and remainedup to 2-fold higher than pre-hurricane background mortality5 years after the hurricane. Spatial point pattern analysisrevealed a patchy distribution of tree mortality during thehurricane sampling interval. Hurricane Fran resulted in a dramaticincrease in average gap size from ca. 400 m² pre-hurricane toca 1100 m² after the hurricane, whereas maximum gap sizes reached18–34 times larger than the pre-hurricane levels.     

中国麻阳河国家级自然保护区黑叶猴种群数量估计与分布

2012年10月至2015年5月,对中国贵州省麻阳河国家级自然保护区黑叶猴(Trachypithecus francoisi)的种群数量和分布进行了调查研究。本次调查采用了直接观察猴群计数、夜宿地观察、问卷调查和访问、未出版资料及文献补充4种调查方法。结果表明,麻阳河国家级自然保护区及周边共有黑叶猴72群(含保护区外2群)。基于直接计数的25个猴群,计算猴群平均大小为(7.7±2.9)只,并以此计算保护区及周边黑叶猴数量为554只。其中,凉桥片区共有41群,315只;龚溪口片区共有16群,123只;务川片区共有15群,116只。调查发现保护区黑叶猴的分布基本以麻阳河、洪渡河及其支流兰子河为中轴,以箱状河谷的峭壁上和河岸附近的植被区作为主要活动范围。67群猴群发现点位于离河流中轴线缓冲距1 500 m区域以内,占总群数的93.1%。因此,为了确保该物种的生存以及缓解当地人猴冲突,建议重点加强对河流两岸栖息地的保护管理和自然植被恢复,尤其在人口稠密区更为必要。     

Taxonomy and distribution of the françois' langur (Presbytis francoisi)

This paper discusses the taxonomy and distribution ofPresbytis francoisi. We are especially concerned with the classification of the white-headed langur.T'an (1957) suggested that the white-headed langur be classified as a separate species,Presbytis leucocephalus. We suggest that the white-headed langur is a subspecies ofPresbytis francoisi and should be referred to asP. francoisi leucocephalus. The distribution of the six subspecies of the françois' langur,P. f. delacouri, P. f. francoisi, P. f. hatinhensis, P. f. laotum, P. f. leucocephalus, andP. f. poliocephalus, is limited to southeastern Asia.     

贵州麻阳河自然保护区黑叶猴利用洞穴的观察

非人灵长类利用洞穴是非常稀少的现象。2003年11—12月和2004年初在贵州麻阳河自然保护区观察到黑叶猴(Trachypithecusfranoisi)有利用洞穴的现象。白天有二群(分别为10和14只)在栖息地附近活动,黄昏前回到悬崖边几个喀斯特地形山洞中的一个洞。躲避风雨等不良的气候条件、获得矿物质、安全等因素可能是黑叶猴利用洞穴的原因。     

Ranging behavior of the François’ langur (<Emphasis Type="Italic">Trachypithecus francoisi</Emphasis>) in the Fusui Nature Reserve,China

Data on activity budgets and ranging patterns were collected from March to December 2001 for one group of François’ langurs (Trachypithecus francoisi) inhabiting a forested part of the Fusui Nature Reserve, Guangxi province, China. Our results indicate that the total size of the home range of the study group during the study period was 19 ha. The majority of their activities (52%) occurred within a small area, 22%, of their home range, and was concentrated in or near quadrats containing their sleeping sites, which may reduce the time and energetic cost of travel. The extent of the ranging behavior varied between months, with the smallest, 7 ha, recorded in July and the largest, 13.5 ha, in November. There was no significant difference between seasons. The monthly mean daily path lengths varied from 341 to 577 m. The daily path lengths showed significant seasonal changes: the path lengths were longer during the dry season than in the rainy season, which may be related to the scarcity of preferred food resources during the dry season.