未来气候变化对四种木姜子地理分布的影响

该文利用最大墒模型(Maxent)和地理信息系统(ArcGIS 10.3)软件对中国木姜子属(Litsea)四种资源植物在我国当代、未来(2061年—2080年)气候条件下的潜在分布区进行预测,并对其适宜区进行分析和划分。结果表明:山鸡椒(Litsea cubeba)适宜区广泛分布在长江以南区域,在未来时段2061年—2080年两种(RCP2.6、RCP8.5)二氧化碳浓度情景下适宜区面积分别减少4.9%和0.5%; 毛豹皮樟(L. coreana)适宜区主要分布在中亚热带及北亚热带区域,分布相对偏北,其在未来2061年—2080年两种二氧化碳浓度情景下适宜区面积分别增加5.6%和4.5%; 华南木姜子(L. greenmaniana)适宜区主要分布在我国南亚热带区域; 毛叶木姜子(L. mollis)适宜区广泛分布在亚热带区域。这两种树种在未来气候RCP2.6情景下适生面积减少1.0%和3.3%,在RCP8.5情景下减少5.6%和8.3%。上述结果说明木姜子属不同种由于生态习性差异对未来的气候变化的响应不尽相同,对这些植物引种栽培须考虑气候变化的影响。     

气候变化下西南地区植物功能型地理分布响应

以中国西南地区(云南、贵州、四川和重庆)为研究区,基于中国植被图划分植物功能型,筛选影响各植物功能型分布的主导环境因子,进而通过最大熵模型结合未来气候情景(2050年)预测西南地区植物功能型地理分布。结果表明:(1)根据植物冠层特征(针叶/阔叶、常绿/落叶)及对水分和温度的需求,结合研究区实际植被数据,筛选得到15类植物功能型,包含6类乔木、6类灌木和3类草本功能型;(2)影响西南地区热带乔木分布的主导因子为最冷月最低温度和年降水量(贡献率达90.3%),亚热带植物功能型分布主要受到温度变化影响(贡献率达41.7%),温带植物功能型则受降水因子的影响最大(贡献率约40.1%),高寒草甸草和高寒常绿阔叶灌木主要受温度和海拔因子影响,高寒落叶阔叶灌木受降水因子影响大;(3)随CO_2排放量增加,未来西南各植物功能型分布呈现不同变化,其中,热带常绿阔叶乔木适宜区逐渐扩大;亚热带落叶木本类植物功能型的高适宜区面积2050年(RCP8.5)增至10.3%,呈东移趋势;亚热带常绿木本和草本类植物功能型适宜区广(占研究区总面积86.5%),未来气候下分布呈不规则波动;温带植物功能型(除温带灌木类外)适宜区面积减小至2050年(RCP8.5)的13.6%;温带常绿针叶灌木适宜区面积增大,2050年(RCP2.6)高适宜区向西移动且面积增至当前的8.25倍;高寒类植物功能型适宜区面积则呈缩小趋势,高适宜区东移。     

单叶蔷薇潜在适宜区预测及其渐危机制研究

基于搜集到的45个单叶蔷薇地理分布坐标和29个环境因子数据,利用GIS和MaxEnt软件分析单叶蔷薇在中国新疆的潜在适宜区,探究环境因子与单叶蔷薇分布之间的关系,确定主要影响因子及其阈值,为单叶蔷薇种群资源保护和修复提供科学依据。结果表明：(1)最干月份降水量、年平均降雨量、最冷季节平均温度是影响现代单叶蔷薇适宜区分布的主要影响因子,利于单叶蔷薇生长的上述相关阈值依次为5.56~10.90 mm、169.62~258.75 mm、-12.48～-9.86 ℃。(2)29个环境因子影响下的现代单叶蔷薇的适宜区总面积达19.85×10₄ km₂,占新疆总面积的11.96%,主要集中于80°13′~91°6′E,42°33′~48°23′N之间,高度适宜区仅0.63×10₄ km₂,主要分布在乌鲁木齐、阜康、昌吉、呼图壁、玛纳斯、石河子、沙湾、乌苏以及塔城地区。(3)未来气候模拟下,除2021-2040年SSPs126、SSPs245、SSPs585情景中的高度适宜区和2041-2060年SSPs126的中度适宜区面积略有扩增外,其他情景下单叶蔷薇潜在适宜区均呈现明显的缩减趋势;2041-2060年SSPs126情景下分布中心向东南移动,2021-2040年SSPs585情景下分布中心基本保持不变,其他情景下分布中心均出现向高纬度迁移的趋势。(4)加入人类足迹数据后的现代单叶蔷薇适宜区显著减少,人类足迹因子贡献率高达63.2%,表明人类活动对单叶蔷薇适宜区有显著的消极影响。     

中国中生代的马通蕨科植物:化石记录、多样性与时空分布特征*

现生真蕨目马通蕨科(Matoniaceae)植物仅存Matonia和Phanerosorus两属, 集中分布于马来西亚、印度尼西亚等热带地区。马通蕨科植物在中生代时期全球广布, 且主要分布于热带、亚热带地区, 有近9个属, 被作为热带、亚热带气候的标志性植物化石之一。本文梳理总结了中国中生代的马通蕨科化石记录并分析其多样性特征, 共计有2属16种, 包括异脉蕨属(Phlebopteris) 15种和准马通蕨属(Matonidium) 1种。对其化石记录和地质地理分布分析表明, 晚三叠世时期, 异脉蕨属植物广泛分布于热带—亚热带湿热气候区, 包括华南一带的四川、湖北、 云南、西藏、福建等地; 早侏罗世时期, 其分布逐渐向北方扩展, 在南、北方植物区系界线附近均有发现; 中侏罗世局限于湖北、青海等地; 早白垩世时仅在黑龙江和西藏少量发现。准马通蕨属仅在黑龙江地区的早白垩世地层中发现。整体上, 马通蕨科在中国中生代的分布范围变迁与气候带范围变化相吻合。     

不同气候条件下沙冬青属植物在我国的潜在分布——基于生态位模型预测

沙冬青属（Ammopiptanthus）植物是古地中海第三纪孑遗濒危物种,包括沙冬青（Ammopiptanthus mgolicus）和矮沙冬青（Ammopiptanthus nanus）,主要分布在我国西北干旱、半干旱地区,其不仅具有较高的研究价值,同时对我国西北干旱地区生态环境具有十分重要的作用。近年来由于全球气候变化及人为干扰等因素,沙冬青属植物天然分布面积骤缩,濒临灭绝。本研究利用MaxEnt模型、Bioclim模型和Domain模型对沙冬青属植物在我国末次间冰期（Last Interglacial）、末次冰盛期（Last Glacial Maximum）、当代和2050年（RCP4.5和RCP8.5）4个时期气候情景下的潜在适生区进行预测。结果表明：MaxEnt模型对沙冬青属植物潜在分布区的预测具有极高的准确度,所有模型的平均受试者工作特征曲线下面积（AUC测试值）均高于0.80。当代沙冬青最佳及高适生区占全国总面积的2.78%,主要集中在内蒙古中部、宁夏北部和甘肃北部等地;未来沙冬青最佳及高适生区在现有分布范围呈现向外扩张的趋势,主要分布在内蒙古鄂托克旗、鄂尔多斯、阿拉善左旗、宁夏吴忠和甘肃民勒县等地。当代矮沙冬青最佳及高适生区占全国总面积的2.23%,主要集中在新疆南部;未来矮沙冬青最佳及高适生区向新疆乌恰县南部、乌鲁木齐北部移动和扩大,主要分布在新疆乌恰县、乌苏市、吐鲁番市和乌鲁木齐市。未来2050年（RCP4.5和RCP8.5）两种气候情景下沙冬青和矮沙冬青的潜在分布总面积均有所增加,与当代相比变化不明显,但不同适生等级的潜在分布面积变化较大,在更高的CO₂排放量（RCP8.5）情景下沙冬青和矮冬青的最佳及高适生区范围的预测结果都将减少。从气候因素角度考虑,研究表明未来气候情景下沙冬青属植物的适生区变化过程中,年均温（Bio1）、最湿月降水量（Bio13）和温度季节性变化（Bio4）是影响沙冬青属植物分布的关键因子,并为我国西北干旱半干旱地区具有重要的经济价值并将持续其生态服务功能。     

十万大山山地常绿阔叶林群落物种组成与结构特征

十万大山是广西生物多样性热点区域之一,其主要植被类型是山地常绿阔叶林。为了解区域内山地常绿阔叶林的群落现状及优势种群结构的发展现状,该文以十万大山山地常绿阔叶林1 hm²固定监测样地中胸径(DBH)≥1 cm的木本植物为研究对象,分析其物种组成、径级结构、树高结构并用g(r)函数分析优势种的空间分布格局。结果表明:(1)群落中DBH≥1 cm的木本植物共计7 517株,隶属52科108属153种; 群落的优势种有云南桤叶树(Clethra delavayi)、银木荷(Schima argentea)、毛折柄茶(Hartia villosa)、红锥(Castanopsis hystrix)、黄杞(Engelhardtia roxburghiana)、罗伞树(Ardisia quinquegona)、鼠刺(Itea chinensis)、腺叶山矾(Symplocos adenophylla)、假杨桐(Eurya subintegra)、毛冬青(Ilex pubescens),但优势种的优势地位不明显。(2)群落整体平均DBH为5.51 cm,径级、树高分布呈近似倒“J”型; 优势种的径级分布多呈倒“J”型或“L”型,群落有较强的更新能力。(3)群落优势种稳定共存; 优势种在样地中呈聚集分布,但优势种间聚集分布的位置有差异。总体而言,群落目前更新状态良好,群落中已有顶极群落优势种的存在,但群落具有一定的次生性特征,还未到达稳定的顶极群落状态,优势种间能稳定共存,有向稳定顶极群落演替的潜力,应继续加强管护,促进十万大山山地常绿阔叶林群落的更新与生存。     

乌冈栎的潜在分布模拟及分析

了解物种的分布特征和动态,对生物多样性保护和恢复具有重要意义。乌冈栎(Quercus phillyraeoides)广布东亚亚热带,是常绿阔叶林的重要组成树种,具有重要生态功能和经济价值。本研究根据乌冈栎134个分布点和9个环境变量,用MaxEnt预测、分析其在当前(1950—2000年)和未来(2060—2080年)气候下的潜在分布格局。综合利用百分比贡献率、置换重要值和刀切法检验气候因子对乌冈栎分布的影响。结果表明:当前潜在分布区与已知分布记录有很好的对应,最适宜分布区涵盖了中国东部、中国西南部及日本南部,占总适宜区的29.9%;最暖季度降水量和最暖月最高温对乌冈栎的潜在分布影响最大;未来随着二氧化碳浓度逐渐升高,乌冈栎的潜在适宜分布区面积将逐渐减少,高度适宜区将锐减,特别东部沿海适宜区将逐渐丧失。本研究阐明了未来气候变化对乌冈栎潜在分布的影响,可为东亚常绿阔叶林生态系统的保护和恢复提供基础资料。     

四种常绿乔木潜在及未来分布区模拟研究

基于《中国木本植物分布图集》和Arc GIS地理信息平台,通过Climate China模型提取2000s(1990-2009)、2020s(2010-2039)、2050s(2040-2069)三个时段的13个气候变量数据为主要气候信息源,采用最大熵法(MaxEnt)生态位模型对四种常绿乔木在中国范围的潜在适生分布区进行模拟预测,得出该四种乔木在2000s、2020s、2050s的分布变化。结果表明:MaxEnt生态位模型模拟的该四种常绿乔木潜在适生分布范围大于文献记载中的分布区域;影响该四种常绿乔木分布的主要气候变量并不完全一致;在未来气候变化下,该四种常绿乔木潜在适生分布区的变化趋势不同。研究结果可为植物适生区划、园林绿化树种引种栽培区的选择提供理论指导。     

秦岭芍药属植物及其地理分布修订

在野外调查的基础上,结合查阅标本和文献比对,对秦岭地区芍药属(Paeonia)植物及其地理分布进行修订。结果表明,秦岭地区分布有芍药属8个野生种及1个栽培种,可分为牡丹组(Section Mouton DC.)和芍药组(Sect. Paeonia)。地理分布格局研究表明：芍药组内4个种：草芍药(P. obovata)、美丽芍药(P. mairei)、芍药(P. lactiflora)、川赤芍(P. anomala subsp. veitchii)和牡丹组中的牡丹(P. suffruticosa Andrews)、紫斑牡丹(P. rockii)为秦岭广布种,卵叶牡丹(P. qiui)和杨山牡丹(P. ostii)为秦岭中东部分布种,矮牡丹(P.jishanensis)为秦岭东部分布种。根据修订,给出了秦岭地区芍药属植物分种检索表。     

常绿阔叶林植物叶片N、P化学计量特征对毛竹扩张的响应

为从生态化学计量内平衡角度解释常绿阔叶林不同层次植物对毛竹(Phyllostachys edulis)扩张的生存响应差异性,该研究采用空间代替时间的方法,在江西井冈山国家级自然保护区沿毛竹扩张方向选取典型毛竹-常绿阔叶林界面,依次设置毛竹林、竹阔混交林和常绿阔叶林样地,比较分析了毛竹扩张方向上样地内不同乔木层、灌木层、草本层植物叶片及土壤N、P含量及比例。结果表明:(1)从毛竹林到阔叶林,土壤N含量上升,P含量下降,N:P上升(P<0.05); 乔木层树种 [红楠(Machilus thunbergii)、赤杨叶(Alniphyllum fortunei)及交让木(Daphniphyllum macropodum)]叶片P含量下降,N:P上升(P<0.05); 除灌木层的红果山胡椒(Lindera erythrocarpa)外,各林分中的灌木层和草本层植物N、P含量及比例变化较小。(2)土壤N:P与乔木层、草本层和灌木层植物叶片N:P分布呈显著正相关、负相关与不相关。(3)在各林分中,毛竹叶片N、P含量及比例较稳定。综上认为,毛竹通过改变土壤N、P化学计量特征进行扩张,引起植物体N、P元素化学计量特征发生变化。灌木及草本植物受土壤异质性影响较小,但是乔木层植物N、P元素化学计量特征却因此失衡,这可能是阔叶林乔木层树种存亡受威胁的重要原因。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.