A Plant Needs Ants like a Dog Needs Fleas: Myrmelachista schumanni Ants Gall Many Tree Species to Create Housing

Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Alth

基于广义模型和分类回归树的中国常见树种地理分布模拟研究

研究植被、物种分布与环境的关系一直是生态学中的重点。长期以来，在全球变化与陆地生态系统的研究中，主要研究重点是对大尺度植被分布的模拟和预测，并建立了大量的气候－植被分布关系模型。而对于物种潜在分布的模拟和预测，国内外相关的研究较少。近年来，随着统计技术和地理信息系统的发展，用于预测物种分布的统计模型技术得到了迅速的发展。统计模型技术已被广泛应用于生物地理分布、植物群落、生物多样性、气候变化影响评估等方面。 本论文基于当前在物种分布研究中应用广泛的广义线性模型、广义加法模型及分类回归树3种统计模型技术，对我国常见树种的地理分布进行模拟分析，并比较不同模型模拟精度的优劣，将模拟精度较高的模型应用于预测未来气候情景下我国几种主要树种的未来潜在地理分布。 基于建立的广义线性模型（GLM）、二次项逐步回归广义线性模型（SGLM）、广义加法模型（GAM）和分类回归树（CART）4个模型对我国20种常见树种地理分布进行模拟，结果表明，4个模型均有较高的模拟精度。GAM的模拟精度最高;添加二次项并进行逐步回归有效的提高了GLM的模拟精度;CART是一种基于规则的模型技术，模拟结果比GLM稍好，比GAM略差。 对不同树种的模拟分析表明，4个模型对于主要分布在暖温带落叶阔叶林区域的油松、辽东栎分布的模拟结果较差;GLM对分布在温带针阔混交林中红松、蒙古栎、胡桃楸和糠椴的模拟结果不太理想;4个模型对分布在中国亚热带常绿阔叶林区域的树种均表现出较高的模拟精度;对广布种也表现出很高的模拟精度。 结合地理信息系统，以地图形式将青冈、油松的模拟结果表示出来。结果表明：地理信息系统直观的反映出了模型模拟结果差异。4个模型均能很好模拟青冈的分布，且模拟结果接近;而对油松分布模拟结果4个模型均不甚理想，以GLM最差。这些结果与模型模拟评估结果相吻合。 在未来气候变化情景下，基于4个模型模拟结果优劣，以我国三种主要造林树种马尾松、油松、红松和两种常见树种青冈、蒙古栎为研究对象，分析其未来变化趋势。结果表明，未来气候变化情景下，对于马尾松而言，4个模型均预测马尾松在基本保持原有分布的基础上，其未来潜在分布区域均有所扩大，且有向西和向北扩展的趋势;对于油松而言，基于GLM、SGLM和GAM3个模型，油松的未来潜在分布除有北移的趋势外，其分布区还将向东北和西南两个方向扩展;对于红松而言，基于SGLM、GAM和CART3个模型的预测结果较为接近，即红松的未来潜在分布区域将有所减少;对蒙古栎而言，4个模型预测蒙古栎未来分布均将向西扩展;对青冈而言，4个模型预测青冈能基本保持其原有分布区，并向西和向北扩展，其中CART预测结果还表明，青冈在广东南部及广西南部的分布区域将消失。

A new species of Amolops (Anura : Ranidae) from Yunnan, China, with a discussion of karyological diversity in Amolops

We describe a new species, Amolops tuberodepressus, from the mountainous regions of Jingdong County, Yunnan Province, China. This species differs from all other congeners in a combination of both karyological and morphological characteristics. Morphologically, the new species resembles A. mantzorum, A. kangtingensis, A. jinjiangensis, and A. liangshanensis occurring in southern Sichuan and northern Yunnan and may easily be confused with those species. However, Amolops tuberodepressus differs from those species by the presence of a distinct tympanum, flatter supratympanic fold, flatter tubercles on the flanks, and absence of a dorsolateral Fold. Karyological evidence also strongly supports the distinctness of the new species. A consideration of one Karyological character demonstrates that species of Amolops in southwestern China all share secondary constrictions on chromosome pair six. In view of the morphological similarity among species df Amolops in southwestern China, these species may have only recently diverged from a common ancestral species.

Molecular evidence for double maternal origins of the diploid hybrid Hippophae goniocarpa (Elaeagnaceae)

Homoploid hybrid plant species are rare, and the mechanisms of their speciation are largely unknown, especially for homoploid hybrid tree species. Two contrasting hypotheses have been proposed to explain the origin of Hippophae goniocarpa: (1) it is a diploid hybrid originating from H. rhamnoides ssp. sinensis x H. neurocarpa ssp. neurocarpa, and (2) it originated via marginal differentiation from H. rhamnoides ssp. sinensis. Regardless of which of these hypotheses is true (if either), previous studies have suggested that H. rhamnoides ssp. sinensis is the only maternal donor for this hybrid species. In this study, we aim to elucidate the maternal composition of H. goniocarpa and to test the two hypotheses. For this purpose, we sequenced the maternal chloroplast DNA trnL-F region of 75 individuals representing H. goniocarpa, H. rhamnoides ssp. sinensis, and H. neurocarpa ssp. neurocarpa in two co-occurring sites of the taxa. Seven haplotypes were identified from three taxonomic units, and their phylogenetic relationships were further constructed by means of maximum parsimony, maximum likelihood, and network analyses. These seven haplotypes clustered into two distinct, highly divergent lineages. Two haplotypes from one lineage were found in H. rhamnoides ssp. sinensis, and five (representing the other lineage) in H. neurocarpa ssp. neurocarpa. Hippophae goniocarpa shared four common haplotypes from both lineages, but the haplotypes detected from the two populations differed to some extent, and in each case were identical to local haplotypes of the putative parental species. Thus, both H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa appear to have together contributed to the maternal establishment of H. goniocarpa. These results clearly demonstrate that the marginal origin hypothesis should be rejected, and support the hybrid origin hypothesis. Hippophae goniocarpa exhibits a sympatric distribution with its two parent species, without occupying new niches or displaying complete ecological isolation. However, this species has effectively developed reproductive isolation from its sympatric parent species. Our preliminary results suggest that H. goniocarpa may provide a useful model system for studying diploid hybrid speciation in trees. (c) 2008 The Linnean Society of London.

中国特有针叶树种对气候变化的敏感性研究

About 214 trees in 9 sampling sites, representing 5 endemic conifer species, were collected from the western Sichuan Province and eastern Qinghai Province, China. In this study, structure we try to investigate tree-ring sensitivity to climate in order to obtain primary information of reconstructing past climate from the trees in this region. All the 5 species present distinct ring boundaries ^ few ABS(absent rings) and available for cross-dating,which are all past the test by program COFECHA. Statistics for all the 8 tree-ring width residual chronologies present significant inter-correlation between series and high values of mean sensitivity. As well as the maximum latewood density of Picea crassifolia Kom and Pinus densata Mast. These results indicate usefulness of these chronologies for dendrochronological studies. Pearson correlation analyses were applied to provide a basic estimate of the causal relationships between tree-ring width and climate factors. We found some significant relationships between tree-ring width> maximum density and temperature as well as precipitation. Especially, there is high correlation between the maximum density of the Picea crassifolia Kom and the index of moisture, the ratio of precipitation and temperature, which can indicate well the climate; however the higher correlation can be see between the maximum density of Pinus densata Mast and the total temperature from June to September. Regardless of tree species, chronologies in our study region presented accordant variations of which may reveal strong common climate signal. Thus these chronologies are shown to be dependable for building tree-ring network in the nearly future. However, there are limitations in this study, only monthly mean of temperature and precipitation were available. Also, for this typical subtropical mountain system, meteorological stations are usually located in valley and biased to represent moisture conditions on the slopes. Thus the estimation of precipitation both in temporal and spatial domain was rather restricted. Further study, such as wood anatomy, physiology and densitometry, are needed for better understanding the environmental and climatic history in this area.

稻属的系统发育基因组学研究

稻属（OrvzaL．）是禾本科(Poaceae)中的重要植物类群，包含20多个野生种和两个栽培种，共有十个基因组类型，即A，B，C，E，F，G，BC，CD，HJ和HK，蕴藏了极为丰富的遗传资源，是水稻遗传改良的重要基因库。考虑到该属现存物种中的多倍体都是由二倍体杂交起源的，因此，弄清二倍体基因组之间的进化关系对于正确理解整个稻属的进化历史至关重要，同时也为稻属及其近缘类群的进化生物学、比较基因组学和功能基因学研究等提供了一个重要的工作基础。迄今，对稻属各基因组之间的系统发育关系还没有一致的结论，特别是对A、B和C基因组三者之间的关系，以及稻属基部类群的归属问题还存在争议。本研究选取来自不同二倍体基因组的6个稻属物种为研究对象，以近缘属Leersia中的L，tisserantti作外类群，通过对基因组水平的多基因序列数据的详尽分析，探讨了稻属二倍体基因组之间的亲缘关系问题，基因树与基因树之间冲突的机理，以及利用基因组水平的多基因序列做系统发育分析的方法，主要研究结果如下。 利用已完成的水稻两亚种（O．sativaL．ssp. indica和O．sativaL．ssp.japonica）的全基因组序列，筛选并扩增出遍布核基因组12条染色体的142个单拷贝核基因片段。通过对全部基因位点的合并分析，我们得到了一棵有完全分辨并得到显著统计支持的系统树。分别提取各基因的外显子区、内含子区和第三密码子进行合并建树时发现，除了合并外显子区的MP分析以外，所得系统树的树形均不变，说明这棵树基本上不会因为选取基因组不同区域或碱基位点而改变，尽管不同区域或碱基位点受到不同的选择约束力。以基因为单位进行放回式抽样也强烈支持合并建树的分析结果，表明多基因合并序列的系统发育估计并没有受到少数特殊基因的支配。为了考察基因组内物种取样对建树的影响，我们增加了2个A基因组物种以及C基因组的另外两个物种，随机选取其中的62个基因位点进行扩增和测序（增加的O．sativa的序列来自BGI-RIS数据库）。将全部II个物种62个基因位点的序列合并建树分析，得到基因组之间的进化关系均未改变。我们进一步评估了合并数据的系统误差，结果发现，合并数据的系统发育重建也未受到系统误差的影响。综上所述，本研究通过系统发育基因组学方法所得到的系统树反映了类群真实的进化关系。 为了深入探讨以往研究中出现相互矛盾的系统发育关系的原因，我们对142个基因位点分别做了单独的建树分析，并用系统发育网络方法分析了数据中基因之间系统发育信息矛盾的集中位置及其矛盾程度。基于单基因的建树分析及系统误差分析，我们排除了随机误差和系统误差直接造成基因之间信息冲突的可能性。基于溯祖理论( Coalescence theory)的进一步分析表明，稻属进化过程中发生了两次世代间隔较短的连续分化事件，由于祖先居群较大引起基因的谱系分选，进而使得在利用现有物种基因序列来重建这些分化事件时基因树不能正确反映物种树，且呈现出基因组水平的基因树冲突现象。这两次间隔较短的连续分化事件分别对应了稻属中两次物种快速分化过程，整个稻属基因组的多样性几乎都是在这两次物种快速分化过程中形成的。随机抽样分析表明，需要大量的分子序列数据才能正确分辨稻属二倍体基因组的系统发育关系（若取95%的概率，则至少需要120个基因或50kb的随机碱基位点）。本研究用基因组水平的多基因合并数据克服了谱系分选对构建系统树所带来的“噪音”，在存在广泛单基因系统发育信息矛盾的前提下获得了对物种树的正确估计，这充分证明系统发育基因组学方法在解决快速分化类群的进化关系问题中有着巨大潜力和广阔的应用前景。 基于本文所采用的142个核基因，我们初步探讨了利用多基因序列数据构建系统树时如何进行模型选择和插入缺失编码等问题，并评估了数据缺失对基因组水平系统发育重建的影响。结果表明，对合并数据而言，混合模型比单一模型能更好的拟合数据的进化模式;找到合并数据中异质性的根源并做出适当的数据分割是成功运用混合模型的关键;某些模型成分在提高模型对数据的适合度上发挥着重要作用，尤其要考虑位点之间以及谱系之间的突变速率异质性。我们认为，在设置模型时，最复杂的不一定是最好的，把握数据中最重要的进化特征远比简单的增加模型的复杂度重要。插入缺失的编码分析表明，编码后显著增加了对A基因组和B基因组聚为一枝的支持，但对稻属基部类群的分辨状况改善不明显。另外，我们通过去除数据缺失比例较大的类群来降低数据缺 失对系统发育推断的影响，结果所得的系统发育关系不变，支持率也仅有极微小的变化，说明基因组水平的多基因数据由于具有丰富的系统发育信息，因而对数据缺失具有很好的缓冲能力。

云南中部无量山黑长臂猿(Nomascus concolor jingdongensis)栖息地乔木层物种多样性和结构特征

无量山是黑长臂猿景东亚种的唯一分布区,现栖息着98群500余只黑长臂猿。长臂猿是典型的树栖性灵长类动物,通过对无量山西坡大寨子地区250个样方的调查,分析了随海拔梯度升高,黑长臂猿栖息地植被乔木层物种多样性和结构的变化情况。共记录乔木111种,隶属于33科;木质藤本23种,隶属于18科。其中优势科主要有樟科(Lauraceae)、木兰科(Magnoliaceae)、壳斗科(Fagaceae)、山茶科(Theaceae)和杜鹃花科(Ericaceae)。根据不同海拔乔木层物种组成的差异,该区可划分为半湿润常绿阔叶林(2100~2300m)和中山湿性常绿阔叶林(2400~2600m)两种植被类型。多样性指数(Shannon-Wiener指数)随海拔升高在两种植被类型中均呈下降趋势;均匀度指数(Pielou指数)在半湿润常绿阔叶林中呈下降趋势,在中山湿性常绿阔叶林中无明显变化。半湿润常绿阔叶林中,阳坡的乔木物种多样性低于阴坡;而阳坡物种多样性在两种植被类型间差异显著。随着海拔的升高,乔木层的平均高度和上层乔木(Ⅰ层)的比例均逐渐降低,但下层乔木却呈上升趋势。6种优势乔木树种的种群年龄结构分析表明,该区植被的乔木层呈...

FEEDING AND VOCAL BEHAVIORS OF BLACK GIBBONS (HYLOBATES-CONCOLOR) IN YUNNAN - A PRELIMINARY-STUDY

Feeding and vocal behaviours of wild black gibbons (Hylobates concolor) were observed from 1987 to 1989 in south-western Yunnan, notably H. concolor jingdongensis at Mt. Wuliang (24-degrees 18-42'N, 100-degrees 30-50'E) in the early spring of 1989. 12 plant species were observed to have been eaten by the gibbons; these included tree species, lianas and epiphytes. Approximately 21 % of feeding time was devoted to eating fruits, 61 % to leaf buds and shoots, 7 % to flowers and 11 % to leaves. The gibbons preferred fruits to leaves even though they commonly ate leaves. In this study, the morning songs (duet and solo), reponsive (territorial) songs, alarm calls and communication calls were recorded. The gibbons sang their morning songs mainly in the early morning, with a single bout lasting more than 10 min on average. The singing of a group would trigger other groups, and all groups in an area tended to sing sequentially. The morning duet song bout was dominated by an adult male. The male emitted booms, aa notes, early multimodulated figures, intermediate multimodulated figures and codas, the latter occurring only in duets following the female's great call. The female uttered great calls and abortive great calls. The subadults or juveniles also took part in the morning songs. Lone males were heard to utter solos which lasted longer than the duets of the pairs.