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1.
Pendular motion during brachiation of captive Lagothrix lagothricha lugens and Ateles fusciceps robustus was analyzed to demonstrate similarities, and differences, between these two closely related large bodied atelines. This is the first captive study of the kinematics of brachiation in Lagothrix. Videorecordings of one adult male of each species were made in a specially designed cage constructed at the DuMond Conservancy/Monkey Jungle, Miami, FL. Java software (Jandel Scientific Inc., San Rafael, CA) was used for frame‐by‐frame kinematic analysis of individual strides/steps. Results demonstrate that the sequence of hand and tail contacts differ significantly between the two species with Lagothrix using a new tail hold with every hand hold, while Ateles generally utilizes a new tail hold with only every other hand hold. Stride length and stride frequency, even after adjusting for limb length, also differ significantly between the two species. Lagothrix brachiation utilizes short, choppy strides with quick hand holds, while Ateles uses long, fluid strides with longer hand holds. During brachiation not only is Lagothrix's body significantly less horizontal than that of Ateles but also, within Ateles, there are significant differences between steps depending on tail use. Because of the unique nature of tail use in Ateles, many aspects of body positioning in Lagothrix more closely resemble Ateles steps without a simultaneous tail hold rather than those with one. Overall pendulum length in Lagothrix is shorter than in Ateles. Tail use in Ateles has a significant effect on maximum pendulum length during a step. Although neither species achieves the extreme pendulum effect and long period of free‐flight of hylobatids in fast ricochetal brachiation, in captivity both consistently demonstrate effective brachiation with brief periods of free‐flight and pendular motion. Morphological similarities between ateline brachiators and hylobatids are fewer and less pronounced in Lagothrix than in Ateles. This study demonstrates that Lagothrix brachiation is also less hylobatid‐like than that of Ateles. Am. J. Primatol. 48:263–281, 1999. © 1999 Wiley‐Liss, Inc.  相似文献   

2.
A simple relation (v-lnB) (u-lnx)=c was recognized betweenx as dbh (or individual basal area) andB as the cumulative basal area abovex, for various stands of warm-temperate rain forests of Yakushima Island, southern Japan (v, u andc, parameters). The model parameters explained a difference in the pattern of stand development between secondary succession after clear-felling and gap regeneration within primary forests.  相似文献   

3.
Local and regional vegetation since the last glacial period was reconstructed on the basis of a palynological study of sediment at Iwaya, in the Sea of Japan area, western Japan. During the interstade (before about 30 000 years BP), forests were composed predominantly ofCryptomeria japonica withTsuga sieboldii and cool-temperate deciduous broad-leaved trees. In the pre-full-glacial, the full-glacial and the early late-glacial (30 000-12 000 years BP), forests were dominated by temperate (montane) and boreal (subalpine) Pinaceae andBetula. During the early full-glacial, the pinaceous forests were mixed with cool-temperate trees such asFagus crenata. In the late full-glacial (18 000-16 000 years BP), the maximum development of pinaceous conifer forests was recognized. Cool-temperate broad-leaved forests composed mainly ofF. crenata andQuercus (Lepidobalanus) replaced the pinaceous forests at about 12 000 years BP and were maintained to the early postglacial.Cryptomeria japonica was distributed around the Mikata lowland during the last glacial.Cryptomeria japonica, which began to increase at 16 000 years BP, increased abruptly in the early postglacial and spread throughout the postglacial in the lowlands. After 6300 years BP, lucidophyllous forests composed mainly ofQuercus (Cyclobalanopsis) andCastanopsis were established in the Mikata district; this was later than in the inland and the Pacific Ocean areas in the Kinki region, western Japan. In historic times (afterca 2000 years BP), secondary forest ofPinus densiflora, which can grow as a pioneer in disturbed habitats, spread.  相似文献   

4.
On the basis of fossil pollen, plant macrofossils and fossil wood, vegetation existing around the Itai-Teragatani Site between 26000 and 20000 yr ago was reconstructed. On the upland, there were mixed forests of conifers and deciduous broad-leaved trees throughout the studied period. The forests consisted mainly ofPinus subgen.Haploxylon andQuercus subgen.Lepidobalanus, together withTsuga, Cryptomeria andUlmus-Zelkova. In the wetland, there were stands ofBetula andAlnus in grassland consisting of Cyperaceae, Gramineae,Lysichiton, Thalictrum, Sangusiorba, Umbelliferae and Compositae. The vegetation changed three times during the studied period. The first change, which occurred prior to the fall of the Aira-Tn ash, was characterized by an increase inAbies, Pinus subgen.Haploxylon and hygrophytes, and a decrease inCryptomeria andAlnus. This is considered to reflect a cooler climate, and expansion of grassland. The second change was caused by the fall of the Aira-Tn ash, which caused serious damage to the vegetation. Many taxa, except forAlnus, Cyperaceae andLysichiton, decreased or vanished after the ash fall. The third change was the process of recovery after the damage. The regenerated forests differed from those before the ash fall. With the regeneration conifers andArtemisia increased. This seemed to reflect the changes in climate and ground conditions caused by the accumulation of the ash.  相似文献   

5.
Vegetation history for the study region is reconstructed on the basis of pollen, charcoal and AMS14C investigations of lake sediments from Lago del Segrino (calcareous bedrock) and Lago di Muzzano (siliceous bedrock). Late-glacial forests were characterised byBetula andPinus sylvestris. At the beginning of the Holocene they were replaced by temperate continental forest and shrub communities. A special type of temperate lowland forest, withAbies alba as the most important tree, was present in the period 8300 to 4500 B.P. Subsequently,Fagus, Quercus andAlnus glutinosa were the main forest components andA. alba ceased to be of importance.Castanea sativa andJuglans regia were probably introduced after forest clearance by fire during the first century A.D. On soils derived from siliceous bedrock,C. sativa was already dominant at ca. A.D. 200 (A.D. dates are in calendar years). In limestone areas, however,C. sativa failed to achieve a dominant role. After the introduction ofC. sativa, the main trees were initially oak (Quercus spp.) and later the walnut (Juglans regia). Ostrya carpinifolia became the dominant tree around Lago del Segrino only in the last 100–200 years though it had spread into the area at ca. 5000 cal. B.C. This recent expansion ofOstrya is confirmed at other sites and appears to be controlled by human disturbances involving especially clearance. It is argued that these forests should not be regarded as climax communities. It is suggested that under undisturbed succession they would develop into mixed deciduous forests consisting ofFraxinus excelsior, Tilia, Ulmus, Quercus andAcer.  相似文献   

6.
Cattle and agricultural farming in the western Orinoco Basin began in 1555, and since then fragmentation of continuous forest has occurred. We evaluated the effects of the disturbances and the absence of large primates on plant community composition, diversity, and regeneration patterns. Atelines (Lagothrix and Ateles) inhabited the lowlands close to the Andean mountains, but no longer live in fragmented habitats. Their absence may have negative effects on plant populations because atelines play important roles as seed dispersers in neotropical forests, especially for large-seeded plants, which are rarely swallowed by other seed dispersers. We compared 2 1-ha vegetation plots in forest fragments north of the La Macarena Mountains with 7 plots in continuous forest in Tinigua National Park. Both sites share the same climatic conditions and have similar geological origins. There is floristic affinity between forests with similar ecological characteristics; the fragmented forests are also less diverse than the continuous forests. As predicted, the forest fragments have fewer individuals with large seeds. The results suggest that forest fragmentation and local ateline extinctions affect plant communities, reducing diversity and affecting large-seeded plants.  相似文献   

7.
In the sediments of both of the investigated lakes, the tephra from the Mercato-Ottaviano eruption (Vesuvius, southern Italy) (ca. 7900 B.P.) could be identified. The palynological investigations show that from ca. 9000-7200 B.P. (8000-6000 cal B.C.) deciduous oak forests predominated, with only a few representatives of Mediterranean vegetation. At the transition to the central European Atlantic Period those forests changed to an open vegetation type, dominated byJuniperus andPhillyrea. At about 5500 B.P. (4400 cal B.C.), theJuniperus-Phillyrea vegetation was replaced byQuercus ilex woodland that still occurs on the island of Mljet today and is considered to be the natural vegetation of the Dalmatian coastland. The associated vegetation of theQ. ilex forests changed several times. At the beginning of theQ. ilex period,Juniperus values were still high, but soon they decreased andErica spread. In more recent times theQ. ilex forests were partially replaced by plantations ofPinus halcpensis. Indicators of human impact are sparse throughout the pollen record. Clear evidence for human influence exists only from ca. 3100 B.P. (1300 cal B.C.) whenJuglans andPinus halepensis were introduced to the area. Later,Olea andSecale cultivation can be suggested and further spreading ofJuniperus indicates use of the land as pasture.  相似文献   

8.
Boxwood is a very important component of the natural forests of the eastern Pyrenees. In the low altitudes of these forests, the invasive species Cydalima perspectalis (Walker) causes considerable damage, and there is concern that it will migrate towards the natural forests at higher altitudes. To determine the biological parameters of the local pest population, a semiartificial diet with lyophilized powdered Buxus sempervirens L. leaves was developed. The results obtained indicate that the studied population of C. perspectalis is very similar to the native Japanese population in terms of the number of larval instars to complete development, the development rate and the critical photoperiod for the induction of diapause. It has also been demonstrated that long photoperiods can shorten the duration of larval development. The diapause induction response was classified as type I, and diapause termination was classified as type III. At the two studied temperatures, 25º and 15ºC, the larvae seemed to require a similar number of days in diapause, approximately 3 months, to spontaneously resume development; temperatures can also prompt larvae to resume development. The critical photoperiod in the study area occurs during the second half of August, varying somewhat according to temperature. The greatest defoliation is caused by the offspring of the first generation, while the majority of the larval offspring of the second generation will enter diapause. The survival of natural boxwood in this area will depend on its ability to regrow one or two years after extensive defoliation and on the adaptation of several indigenous natural enemies in the region to feed on C. perspectalis.  相似文献   

9.
Results of a nine-day survey of the chimpanzee habitat in Ugalla area of western Tanzania in 1975 is reported. The most dominant vegetation of the area wasJulbernardia globiflora woodland. Evidence of chimpanzees, both indirect (such as beds, faeces, and food remnants) and direct (calls and actual observation), suggests that chimpanzees are sparsely distributed throughout the area, but that they disproportionately useBrachystegia bussei woodland along escarpments andCynometra-Albizzia riverrine forests. The hilly country of Sisegwa/Mnyangwa was the only area where chimpanzees appeared to be comparatively abundant. Mammal hair found in faeces indicates mammal-predation by the chimpanzees in this area. Hard-shelled fruits ofStrychnos were apparently bitten open without the use of extra-somatic objects. The food repertoire included fruits of the generaAzanza, Canthium, Cordia, andTamarindus.  相似文献   

10.
Death of canopy trees when gaps are formed was studied in a subalpine coniferous forest, central Japan, which was composed ofAbies, Tsuga, Picea, Betula, andSorbus. Typhoons were considered to be the most important cause of the death of canopy trees. The degree of disturbance in each of 16 plots (20 m×20 m) was represented by the percentage of the total basal area of dead trees to that of living and dead canopy trees (disturbance magnitude; MAG). The mortality of canopy trees increased as their dbh increase in the plots of lower MAG than 90%. The mortality varied among genera, andTsuga was characterized as having lower mortality than that of the other conifers. 418 dead trees were observed. The standing dead trees made up 10.7% of the trees, the stem broken trees 46.7%, and the uprooted trees 42.2%. The stem breaking was most frequent inAbies, and the uprooting was most frequent inTsuga, Picea, andBetula. Undeveloped forests, which have the L-shaped dbh distribution, were destroyed only in high degree (70%<MAG), while developed forests were destroyed in various degrees (30%<MAG<100%). The percentage of uprooted trees in basal area decreased with the development of the forest, from 60% to 10%.  相似文献   

11.
Marmosets have reduced second molars of which size and shape are varied in different species. Mesiodistal and buccolingual diameter of the first and second upper molars in 16 species were measured, and molar area (molar rectangle) and M2 reduction index were calculated by the equation,R=(M2 area/M1 area) × 100. This index ranged from 36.1 inSaguinus oedipus geoffroyi to 70.6 which was the largest found inCebuella pygmaea. Species ofSaguinus showed relatively wide variation as well as a consistantly smaller index. The index forCallithrix registered around 60 andLeontopithecus rosalia was positioned within this genus. There was no relationship between this index and body size of each form. The sizes of the first molar and second molar may not significantly correlate either with body size across species, becauseLeontopithecus rosalia had exceptionally large molars for its body size and contrarily genusSaguinus had relatively small molars. When the shape of the mandible was expressed as length/width ratio, the reduction index significantly correlate with this ratio in genusSaguinus andCallithrix, indicating that longer jaw in shape had relatively large M2. The reduction indices of two possible subspecies,S. oedipus geoffroyi andS. o. oedipus, were 36.1 and 47.3, respectively. This difference suggested that there was a difference in diet or function of jaw apparatus beyond subspecies level.  相似文献   

12.
This paper presents the results of pollen analyses from organic sediments of seven cores (299 spectra) in a mountainous area of the north-west Iberian peninsula. The pollen diagrams, supported by seven14C dates, are used to construct a regional pollen sequence covering the main stages of vegetation dynamics, from the last phases of the Late-glacial until the present. During the Late-glacial Interstadial an important development of cryophilous forests (Betula andPinus) was recorded, although various mesophilous and thermophilous tree elements were also present. The Younger Dryas, palynologically clearly defined, is characterized by an important reduction in tree pollen percentages and the expansion of steppe formations (Poaceae andArtemisia). At the beginning of the Holocene, there was an expansion ofQuercus and a spread of other trees, which combined to give a vegetation cover of varied composition but dominated by mixed deciduous forests. Such forest formations prevailed in these mountains until 3000 years ago, when successive deforestation phases are recorded at various times as a result of increased farming activity. The results are compared with data from other mountainous areas in the northern Iberian peninsula and southern France.  相似文献   

13.
I reviewed literature on juvenile mortality in the Platyrrhini in order to evaluate reproductive success in captive breeding. Juvenile mortality includes abortion, premature mortality, stillbirth and death of the unweaned young. The highest losses occur in the Callitrichidae (31% through 3 months of age; 86% through 6 months of age) and in Lagothrixspp. (around 50% through 1 month of age) among the Cebidae. High abortion rates occur in Saguinusand Aotus.High stillbirth incidences are reported for the Callitrichidae (Callithrixand Saguinus)and for the Cebidae (Saimiriand Aotus).Although most mortality occurs in the first week for most species, a considerable proportion of deaths occurs in the period from week 1 until weaning. Important causes of death are trauma and aberrant parental behavior. Prematurity plays an important role in perinatal death among the Callitrichidae. Dystocia is a major cause of stillbirth in Saimiri. Congenital malformations occur in Callithrix, Saguinus, Leontopithecus,and Saimiri.Infectious diseases play a secondary role in mortality, particularly during the first period of life. A higher mortality risk is present if the infant is male, if the litter size is different from two (Callitrichidae), if the mother is primiparous, captive born, or inexperienced, or if the group is small (Callitrichidae) or unstable (Cebidae).  相似文献   

14.
中亚热带4种森林凋落物量、组成、动态及其周转期   总被引:7,自引:0,他引:7  
郭婧  喻林华  方晰  项文化  邓湘雯  路翔 《生态学报》2015,35(14):4668-4677
为研究亚热带次生林保护对森林生态系统养分循环等功能过程的影响。采用凋落物直接收集法,比较湘中丘陵区3种次生林(马尾松+石栎针阔混交林、南酸枣落叶阔叶林、石栎+青冈常绿阔叶林)和杉木人工林的凋落物量、组成特征及其周转期。结果表明:4种林分年凋落物量在414.4—818.2 g m-2a-1之间,3种次生林显著高于杉木人工林,3种次生林两两之间差异不显著,落叶对林分凋落物量的贡献最大,占林分凋落物量的59.9%—66.6%。杉木人工林和南酸枣落叶阔叶林的凋落物量月动态变化呈"双峰型",马尾松+石栎针阔混交林、石栎+青冈常绿阔叶林呈"不规则型"。优势树种的凋落物量对其林分凋落物量的贡献随林分树种多样性的增加而下降,杉木、马尾松凋落物量的月动态与其林分凋落物量的月动态基本呈一致变化趋势,但南酸枣、青冈、石栎没有一致的变化趋势。杉木人工林凋落物分解率最低(0.31),周转期最长(3.2 a),南酸枣落叶阔叶林分解率最高(0.45),周转期最低(2.2 a),凋落物的分解速率和周转随林分树种多样性增加而加快。可见,次生林凋落物量大,且分解快,周转期短,有利于养分归还和具有良好地力维持的能力。  相似文献   

15.
The major larval cuticle protein (LCP) genes I–IV ofDrosophila melanogaster are clustered on the right arm of the second chromosome. By cross-hybridization we cloned the corresponding genes from three different members of theobscura group:D. persimilis, D. pseudoobscura andD. miranda. InD. pseudoobscura andD. persimilis the gene cluster maps to autosome3. In contrast, inD. miranda it was found on theX2 andY sex chromosome. Hence, this exceptional karyotypic situation offers a unique opportunity to analyse the molecular processes underlying the phenomenon of chromosome degeneration. Comparison of LCP genes I–IV in theX2 andY chromosomal region inD. miranda revealed extensive DNA rearrangements at the latter. TheY chromosomal LCP cluster is characterized by DNA insertions which are absent in the correspondingX2 chromosomal DNA, suggesting that these DNA sequences must have invaded this area. In addition, part of the analysedY chromosomal region is duplicated.  相似文献   

16.
The results of small mammal inventories at 11 sites ranging from sea level to 1000 m a.s.l. on the Masoala Peninsula in northeastern Madagascar are presented. The Rodentia and Lipotyphla (ex Insectivora) of this peninsula, that contain extensive areas of lowland rainforest and some montane habitat, were previously poorly known. Fifteen endemic (5 rodents and 10 tenrecs) and 2 introduced species [Rattus rattus (Linnaeus, 1758) andSuncus murinus(Linnaeus, 1766)] were recorded. Species diversity in the lowland forests was reduced as typically found in other lowland sites in the eastern humid forest, while that of the lower montane zone was notably low as compared with other nearby large forested areas to the interior of the peninsula. Several ideas are presented to explain this difference, including the peninsula effect.  相似文献   

17.
We studied the factors affecting the distribution of an endemic shrewSorex samniticus Altobello, 1926 in the Province of Siena, central Italy. Distribution data were obtained by examining pellets from 31 barn owlTyto alba sites (roosts) over a period spanning from 1974 to 2005. We constructed a model using logistic regression analysis on presence/absence data. Results show that an increase in forest dominated byQuercus cerris andCastanea sativa led to the local extinction of this species. Results were confirmed through the examination of one box, with 3044 prey items deposited in layers, that documents the expansion of the species in that area following increased logging ofQuercus cerris andCastanea sativa forests. Cessation of logging has again led to the absence of the species from the area. We discuss these results from the perspective of ecological network planning, showing that utilisation of non-detailed maps, such as Corine Land Cover, that do not distinguish between the various kind of broadleaved forests is inadequate to describe the finer grade of habitat selection of this small mammal.  相似文献   

18.
Using the Braun-Blanquet approach, five associations of boreal forests were distinguished in central Yakutia, the most continental part of eastern Siberia. Ecological features of the syntaxa were explained with the use of the DCA ordination of 50 relevés. All available data from eastern Siberia were involved in the study for syntaxonomic analysis. Central Yakutian boreal forests were classified into two classes:Rhytidio-Laricetea sibiricae Korotkov etErmakov 1999 — ultracontinental light coniferous hemiboreal forests, andVaccinio-Piceetea Br.-Bl. inBr.-Bl. et al. 1939 — typical coniferous taiga forests of northern Eurasia. A new concept of higher syntaxonomic units of the classVaccinio-Piceetea in eastern Siberia has been developed. Three orders represent the diversity of taiga forests: (1)Cladonio-Vaccinietalia Kielland-Lund 1967 (with alliancesHieracio umbellati-Pinion sylvestris Anenkhonov etChytry 1998 andSaxifrago bronchialis-Pinion sylvestris all. nov.) — light coniferous boreal forests occurring in dry and moderately dry oligotrophic sites in various climatic sectors of Northern Eurasia; (2)Lathyro humilis-Laricetalia cajanderi ord. nov. (with alliancesAulacomnio acuminati-Laricion cajanderi all. nov. andRhododendro daurici-Laricion gmelinii all. nov.) — zonal boreal forests with xeric elements, which are typical of regions of northern Asia with cold, dry ultracontinental climate; (3)Ledo-Laricetalia cajanderi ord. prov. (with allianceLedo-Laricion cajanderi prov.) — North Eurasian boreal forests occurring in cold sites with excessive soil moisture, sometimes water-logged. Phytogeography and ecology of these orders are discussed in comparison with other regions of northern Asia.  相似文献   

19.
Soil characteristics of mangrove forests at Amphur Laemngob, Trat Province, east Thailand were investigated in both dry andrainy seasons. Sonneratia alba, Avicennia alba andRhizophora mucronata mainly grew as seaward mangroves.Rhizophora apiculata, Ceriops tagal, Excoecaria agallocha andBruguiera gymnorrhiza grew as meso mangroves in most cases.Lumnitzera racemosa was found as a landward mangrove. The salinity of the soil in which these 8 species grew was significantly higher in the dry season than in the rainy season. Soil pH did not change irrespective of the season. Each species seemed to grow at inherent soil pH. Bruguiera gymnorrhiza, Sonneratia alba andAvicennia marina were found both in Japan and Thailand. The soil pH of each mangrove species was similar in Japan and Thailand. The soil salinity of each mangrove species in Japan was similar to that in Thailand in the dry season. It was suggested that soil pH and salinity in the dry season are the important factors governing the zonal distribution of mangroves.  相似文献   

20.
The ateline monkeys constitute as certain a monophyletic group as there is among primates. The group is intriguing because while their adaptations are well-documented and their monophyly as a group is unquestioned, their phylogenetic interrelationships are controversial. Molecular data indicate a phylogeny at odds with their morphology. Traditional morphological comparisons isolate Alouatta from the atelins, and link Ateles and Brachyteles as a sister group to the exclusion of Lagothrix. In contrast, several recent molecular studies point to a closer relationship between Brachyteles and Lagothrix than between Brachyteles and Ateles. At the heart of the problem lie the assumptions we make about the validity of data and the homology of observed traits. The fossil record further confounds the issue. We must account for the fossil record because it is positive evidence. But we cannot control how much of it there is or how much of it ever will be known. At this point in time, the ateline molecular and fossil record provoke us to examine critically our morphological approach to phylogenetic modeling.  相似文献   

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