海南铜铁岭热带低地雨林植物区系研究

海南铜铁岭热带低地雨林的物种种类十分丰富,在2 600 m2的样地中有维管束植物88科、186属、258种.植物分布区类型组成,主产热带、亚热带的科占79.55%,热带分布属占旧世界分布属的95.08%;热带分布种占种总数的98.84%.热带分布的科、属中,以泛热带分布的科、属最多,分别占科、属总数的62.50%,28.49%.种的分布中以热带亚洲分布及其变型和中国特有成分占的比例最高,分别为55.43%和33.72%;分布至温带的科、属、种分别占科、属、种总数的19.32%,4.92%,1.16%.结果显示了铜铁岭低地雨林的热带北缘的性质.     

A tropical rainforest in Colorado 1.4 million years after the Cretaceous-Tertiary boundary

An extremely diverse lower Paleocene (64.1 million years ago) fossil leaf site from Castle Rock, Colorado, contains fossil litter that is similar to the litter of extant equatorial rainforests. The presence of a high-diversity tropical rainforest is unexpected, because other Paleocene floras are species-poor, a feature generally attributed to the Cretaceous-Tertiary (K-T) extinction. The site occurs on the margin of the Denver Basin in synorogenic sedimentary rocks associated with the rise of the Laramide Front Range. Orographic conditions caused by local topography, combined with equable climate, appear to have allowed for the establishment of rainforests within 1.4 million years of the K-T boundary.     

海南橡胶林与热带雨林土壤微生物区系分析

[目的]研究热带橡胶林与热带雨林土壤微生物区系组成及其生物量,为海南地区橡胶林的生产提供理论参考.[方法]在海南地区分别选取5个橡胶林(儋州、琼中、乐东、万宁和海口)和5个热带雨林(五指山、霸王岭、尖峰岭、吊罗山和鹦哥岭)的样地,每个样地选择13个取样点,旱季和雨季总计260个样本,测定土壤的理化性质(pH、有机质、全氮、全磷和全钾);采用稀释平板分析法测定土壤中微生物数量(细菌、放线菌和真菌);采用线性回归分析方法分析土壤微生物区系、数量特征及其随季节的变化规律.[结果]比较橡胶林与热带雨林土壤的理化性质,二者仅pH差异不显著(P>0.05,下同),其他理化性质的差异均达显著水平(P<0.05,下同).各样地间土壤有机质含量呈显著差异,鹦哥岭与其他样地pH差异显著;儋州与琼中、海口与吊罗山的土壤全氮含量无显著差异;儋州与五指山,琼中与乐东,吊罗山与鹦哥岭的土壤全磷含量无显著差异;乐东与霸王岭、琼中与尖峰岭的土壤全钾含量无显著差异;其他各样地的土壤全磷、全钾和全氮含量差异显著.样地土壤中不同微生物类群数量的排序为细菌>放线菌>真菌,细菌占微生物总量为95.46%~97.60%;在细菌和真菌数量上为热带雨林>橡胶林;放线菌数量上橡胶林>热带雨林.可见,橡胶林与热带雨林三大微生物类群差异均显著.土壤微生物总量上热带雨林>橡胶林;橡胶林各样地中微生物总量排序为乐东>琼中>儋州>万宁>海口,热带雨林各样地中微生物总量排序为鹦哥岭>霸王岭>吊罗山>尖峰岭>五指山.橡胶林和热带雨林中土壤微生物数量随季节变化差异明显,旱季到雨季细菌和真菌数量增大.回归分析结果表明,细菌、放线菌和真菌数量与土壤含水量呈极显著负相关(P<0.01,下同);细菌和真菌与pH无显著相关性,放线菌与pH呈极显著正相关;细菌和真菌数量与有机质呈极显著负相关,仅放线菌数量与有机质无显著相关性.[结论]季节变化对微生物数量造成显著影响.土壤理化性质、地上植被的不同均会对微生物数量产生影响,热带雨林能为细菌和真菌提供更有利的生长条件,橡胶林环境则有利于放线菌生长.要有足够的肥料施入及科学的田间管理相辅,以促进微生物活动将养分转化后供橡胶树生长发育.     

西双版纳热带季节雨林辐射长期变化特征

[目的]太阳辐射是森林生态系统最主要的能量来源,同时是影响森林生态系统区域气候与环境的最重要因素之一.探讨森林辐射长期变化特征,以期为气候变化、热带地区森林生产力、辐射能量平衡的研究以及辐射模型的建立和验证等建立研究基础.[方法]利用西双版纳热带季节雨林14年(2003-2016)辐射实测数据,对不同时间尺度的辐射各分...     

海南热带雨林土壤细菌组成与多样性分析

【目的】明确海南热带雨林土壤细菌的组成与多样性、时空分布规律及对土壤理化性质的响应和功能结构,为海南地区热带雨林的管理和保护提供理论依据。【方法】对海南五大热带雨林吊罗山、五指山、鹦哥岭、霸王岭和尖峰岭的土壤进行采样,每个样地采集13份样本,分旱、雨两季,共130份样本;通过高通量测序技术,分析土壤样本微生物中的细菌组成与多样性随空间位置和季节的变化,应用PICRUSt2功能预测分析土壤细菌功能。【结果】OTU分类统计显示,旱季的细菌OTU数目为10958,雨季的细菌OTU数目为11533,两个季节间差异不显著（P>0.05）。在细菌门水平,热带雨林旱季和雨季土壤细菌的优势菌群为变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、放线菌门（Actinobacteria）、浮霉菌门（Planctomycetes）和疣微菌门（Verrucomicrobia）;两个季节间的拟杆菌门（Bacteroidetes）、放线菌门和蓝藻菌门（Cyanobacteria）丰度差异极显著性（（P<0.01,下同）。在细菌纲水平,热带雨林旱季和雨季土壤细菌的优势菌纲为放线菌纲（Actinobacteria）、酸杆菌纲（Acidobacteria）、α-变形菌纲（Alphaproteobacteria）、浮霉菌纲（Planctomycetacia）和斯巴托菌纲（Spartobacteria）;两个季节间的浮霉菌纲、鞘脂杆菌纲（Sphingobacteriia）、纤线杆菌纲（Ktedonobacteria）和放线菌纲丰度差异极显著。冗余分析（RDA）表明pH和全钾对土壤中细菌的贡献度较高,解释率分别为5.03%和4.28%。ANOSIM和Adonis分析显示不同季节细菌多样性差异不明显,不同地点细菌多样性差异明显。KEGG通路显示吊罗山样本中的细菌功能丰度较其他4个样点少。【结论】海南热带雨林土壤细菌在不同地理位置（取样点）的多样性差异明显,季节变换对土壤细菌的组成影响不明显,pH和全钾是土壤中细菌旱、雨季多样性的重要环境因子。     

Climatic impact of tropical lowland deforestation on nearby montane cloud forests

Tropical montane cloud forests (TMCFs) depend on predictable, frequent, and prolonged immersion in cloud. Clearing upwind lowland forest alters surface energy budgets in ways that influence dry season cloud fields and thus the TMCF environment. Landsat and Geostationary Operational Environmental Satellite imagery show that deforested areas of Costa Rica's Caribbean lowlands remain relatively cloud-free when forested regions have well-developed dry season cumulus cloud fields. Further, regional atmospheric simulations show that cloud base heights are higher over pasture than over tropical forest areas under reasonable dry season conditions. These results suggest that land use in tropical lowlands has serious impacts on ecosystems in adjacent mountains.     

Global correlations in tropical tree species richness and abundance reject neutrality

Patterns of species richness and relative abundance at some scales cannot be distinguished from predictions of null models, including zero-sum neutral models of population change and random speciation-extinction models of evolutionary diversification. Both models predict that species richness or population abundance produced by independent iterations of the same processes in different regions should be uncorrelated. We find instead that the number of species and individuals in families of trees in forest plots are strongly correlated across Southeast Asia, Africa, and tropical America. These correlations imply that deterministic processes influenced by evolutionarily conservative family-level traits constrain the number of confamilial tree species and individuals that can be supported in regional species pools and local assemblages in humid tropical forests.     

Tree dispersion, abundance, and diversity in a tropical dry forest

Patterns of tree abundance and dispersion in a tropical deciduous (dry) forest are summarized. The generalization that tropical trees have spaced adults did not hold. All species were either clumped or randomly dispersed, with rare species more clumped than common species. Breeding system was unrelated to species abundance or dispersion, but clumping was related to mode of seed dispersal. Juvenile densities decreased approximately exponentially away from adults. Rare species gave evidence of poor reproductive performance compared with their performance when common in nearby forests. Patterns of relative species abundance in the dry forest are compared with patterns in other forests, and are explained by a simple stochastic model based on random-walk immigration and extinction set in motion by periodic community disturbance.     

西双版纳热带季节雨林热力效应时空分布特征初探

该文利用西双版纳雾凉季和干热季的气温和树表温观测资料 ,通过实测、对比方法 ,探讨了热带季雨林平均气温及其树表温的时空分布特征 .通过对分布特征和变化规律的分析、研究 ,发现由于热带季节雨林受地方气候和森林结构影响 ,不同区域、不同时间受到太阳辐射影响的差异 ,导致气温和树表温均存在明显的时空差异 ,在林冠附近 ,树冠表温和气温及温度日较差均呈现最大值 ,显示了林冠面具有较强的热力效应 ,且其效应在干热季显著 .在 12 :0 0— 16 :0 0 ,树冠附近空气与树冠表层间的热力传输 ,雾凉季树冠附近气温低于林冠表温 ,热量从树冠传向空气 ;而干热季则反之 ,树冠附近气温高于林冠表温 ,林冠从空气中获得热量 .林内的第二冠层上午和下午气温多高于树冠表温 ,中午前后气温低于树冠表温 ,并且干热季的温差的绝对值大于雾凉季 ;而在林内近地冠层热量多是由树冠传向近旁空气 ,显示了热力传输的时空多变特征 .热带季节雨林林内树表温和气温多呈现逆温分布 ;上午树表面为热源 ;中午则反之 ,多是空气为热源 ;而下午树表面与空气多处于热平衡状态 .热带季节雨林中热力作用复杂、多样 ,使得热力效应时空分布趋于多样化 ,导致小气候环境异质性     

西双版纳热带季节雨林与橡胶林凋落物的持水特性

为了比较热带季节雨林和橡胶林2种植被类型凋落物层的持水能力差异,在云南西双版纳选取了这2种森林,收集了地表凋落物,对比研究2种植被类型的凋落物地表现存量、持水率、持水速率、最大持水量和有效持水量等持水特性的差异。结果表明:橡胶林凋落物地表现存量（3.79 ±0.34）t· hm-2显著高于热带季节雨林（2.19 ±0.14）t·hm-2（独立样本t检验,P=0.012）;橡胶林凋落物的最大持水量（12.50 t·hm-2）显著高于热带季节雨林（5.53 t·hm-2）（独立样本t检验,P=0.000）;同时,橡胶林和热带季节雨林凋落物的有效最大持水量分别为10.63和4.71 t·hm-2,橡胶林具有显著更高的有效最大持水量（独立样本t检验,P=0.000）。因此,橡胶林凋落物无论在数量上还是持水能力上都优于热带季节雨林,橡胶林凋落物具有相对较好的生态持水效果。     

Bacterial diversity in tree canopies of the Atlantic forest

We found an extraordinary level of bacterial biodiversity in the tree leaf canopy of a tropical Atlantic forest by using culture-independent molecular methods. Our survey suggests that each tree species selects for a distinct microbial community. Analysis of the bacterial 16S ribosomal RNA gene sequences revealed that about 97% of the bacteria were unknown species and that the phyllosphere of any one tree species carries at least 95 to 671 bacterial species. The tree canopies of tropical forests likely represent a large reservoir of unexplored microbial diversity.     

Comment on "Global correlations in tropical tree species richness and abundance reject neutrality"

Ricklefs and Renner (Reports, 27 January 2012, p. 464) showed correlations of species richness and individual abundance within families across continents and claimed that neutral theory predicts no such correlation. However, they did not substantiate this claim quantitatively with a neutral model. Here, we show that neutral theory can be consistent with these correlations and, consequently, that the correlations alone cannot reject neutrality.     

热带季节雨林土壤DOC与DN特征及其影响因子

为探明热带季节雨林土壤溶解态有机碳(DOC)、溶解态氮(DN)的时空动态及与土壤温、湿度和土壤酸度的关系,本研究在西双版纳热带季节雨林开展了土壤剖面DOC和DN含量的研究,在同一自然年度,在雾凉季(1月),干季(3月),雨季前期(5月),雨季中期(8月),雨季后期(10月),按0~20、20~40、40~60、60~80和80~100 cm分层采集土壤样品,测定土壤DOC和DN含量、土壤温、湿度和酸度。结果表明:西双版纳热带季节雨林土壤DOC和DN含量在0~60 cm随深度增加而逐层递减,在60~100 cm则随着深度增加而增加,总体表现为表层DOC和DN含量较深层土壤含量高的剖面特征。热带季节雨林各层土壤的DOC和DN的季节动态并不完全一致,呈雨季中后期高,干季低的季节特征。即DOC含量季节差异显著的土层为0~20和20~40 cm,而DN含量仅在0~20 cm土层季节差异显著;土壤温湿度与DOC和DN的关系存在着层间差异,即0~20和20~40 cm土壤DOC的含量与土壤湿度呈显著正相关关系;20~40 cm的DOC含量与土壤温度呈显著正相关关系;0~20和80~100 cm土层的DN含量与土壤湿度有显著的正相关关系;仅0~20 cm土层的土壤温度与DN含量呈显著正相关关系;热带季节雨林土壤DOC和DN的含量与土壤酸度的关系不显著。以上结果表明热带季节雨林各层土壤的DOC和DN对温、湿度和酸度的反馈不同。      

Territorial organization of the lowland classic maya

Thus far I have discussed ancient Maya sociopolitical structure from the upper levels of the hierarchy downward. Let me now summarize their territorial organization from the bottom upward, starting at the hamlet level (Fig. 8). The smallest unit of settlement-one usually overlooked by archeological surveys in the lowland rain forest-was probably a cluster of thatched huts occupied by a group of related families; larger clusters may have been divided into four quadrants along the lines suggested by Coe (26). Because of the long fallow period (6 to 8 years) characteristic of slash-and-burn agriculture in the Petén, these small hamlets are presumed to have changed location over the years, although they probably shifted in a somewhat circular fashion around a tertiary ceremonial-civic center for whose maintenance they were partly responsible. These tertiary centers were spaced at fairly regular intervals around secondary ceremonial-civic centers with pyramids, carved monuments, and palace-like residences. In turn, the secondary centers occurred at such regular intervals as to form hexagonal patterns around primary centers, which were still larger, with acropolises, multiple ceremonial plazas, and greater numbers of monuments. In some cases, the distance between secondary centers was roughly twice the distance between secondary and tertiary centers, creating a lattice of nested hexagonal cells. This pattern, which conforms to a Western theoretical construct, was presumably caused by factors of service function, travel, and transport. The pattern was not recognized by the Maya at all. They simply recognized that a whole series of smaller centers were dependent on a primary center and therefore mentioned its emblem glyph. Linking the centers of the various hexagons were marriage alliances between members of royal dynasties, who had no kinship ties with the farmers in the hamlets. Out of the large number of primary centers available to them, the Maya selected four as regional capitals. True to their cosmology, the Maya regarded these capitals as associated with the four quadrants of their realm, regardless of their actual location. Each was the home city for a very important dynasty whose junior members probably ruled secondary centers. Since the hexagonal lattices were probably adjusted to variations in population density, each of the four quadrants of the Maya realm probably controlled a comparable number of persons. So strong was the cognized model that, despite the rise and fall of individual centers, there seem always to have been four capitals, each associated with a direction and, presumably, with a color. There is still a great deal to learn about the social, political, and territorial organization of the lowland Maya, and parts of the picture presented here need far more data for their confirmation. What seems likely is that the Maya had an overall quadripartite organization (rather than a core and buffer zone) and that within each quadrant there was at least a five-tiered administrative hierarchy of capital, secondary center, tertiary center, village, and hamlet. Perhaps most significant, there was no real conflict between the lattice-like network predicted by locational analysis and the cosmological four-part structure predicted by epigraphy and ethnology.     

The evolution of agriculture in ants

Cultivation of fungi for food by fungus-growing ants (Attini: Formicidae) originated about 50 million years ago. The subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. These patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species farm a diversity of cultivars, and that cultivars are shared occasionally between distantly related ant species, probably by lateral transfer between ant colonies.     

藏东南嘎隆拉和墨脱河谷蚂蚁群落研究

\t\t\t\t\t目的\t\t\t\t\t调查大巴山自然保护区的蚂蚁区系特征。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t采用样地调查法对调查点的地表蚂蚁、土壤蚂蚁与树冠蚂蚁进行采集鉴定与区系分析。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t在大巴山自然保护区共采集到蚂蚁34 328只,分属5亚科32属59种,其中重庆新记录种24种。区系分析表明：在属级水平,大巴山自然保护区蚂蚁以古北界与东洋界为主体,与马来西亚界、澳洲界和新北界关系较为紧密,与新热带界关系最远;在种级水平,以东洋界为优势,与古北界关系最为密切,与马来西亚界有一定联系,与马拉加西界、新热带界关系最远。在中国动物地理区划中,具有显著华中区特征,与华南区和西南区联系紧密,与蒙新区关系最远。\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t大巴山自然保护区蚁科昆虫区系分布受动物地理学规律制约而形成。\t\t\t\t     

Phylogeny of the ants: diversification in the age of angiosperms

We present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects.     

Solar radiation profiles in openings in canopies of aspen and oak

Vertical profiles of solar radiation in openings in forest canopies showed increasing solar radiation with depth in Colorado, but not in Minnesota. A model was developed and tested to calculate solar radiation in openings from the incoming direct and sky radiation and from the depth and diameter of the opening. The increase occurs only with high direct and low sky radiation. The model may explain the geographic and seasonal distribution of the solar radiation profiles and the lack of such observations previously.     

Excavation of a chimpanzee stone tool site in the African rainforest

Chimpanzees from the Tai forest of C?te d'Ivoire produce unintentional flaked stone assemblages at nut-cracking sites, leaving behind a record of tool use and plant consumption that is recoverable with archaeological methods. About 40 kilograms of nutshell and 4 kilograms of stone were excavated at the Panda 100 site. The data unearthed show that chimpanzees transported stones from outcrops and soils to focal points, where they used them as hammers to process foodstuff. The repeated use of activity areas led to refuse accumulation and site formation. The implications of these data for the interpretation of the earliest hominin archaeological record are explored.