Impacts of dust on plant health,survivorship and plant communities in semi‐arid environments

There is a general perception that dust accumulation on plant surfaces causes negative impacts to plants. Consequently, it is common for environmental regulatory agencies to apply vegetation monitoring requirements to oil, gas and mining developments. We use two independent, medium‐term monitoring studies in semi‐arid Australia to examine this relationship at two scales: plant health and survivorship of a threatened subspecies (Tetratheca paynterae paynterae: Elaeocarpaceae) at Windarling Range between 2003 and 2014; and changes in plant health and floristic composition on Barrow Island between 2009 and 2014. Accumulation of dust decreased rapidly with distance from source. At Windarling Range, even at the site with the highest dust load, there was no significant impact on Tetratheca paynterae paynterae compared with the less dusty sites for 10 years. Similarly, there was no significant effect between distance from the source of dust and floristic composition on Barrow Island for 5 years. The probability of plants transitioning to a lower health condition between one year and the next did not appear to be related to dust load. This is further supported by comparing the same site before and after paving the road (removal of dust source), which showed no clear trends. Trends in plant health are likely to be driven more by the variability of cumulative rainfall in the preceding 5 months than dust load. The observed temporal variation in the mean dust load may also be related to variation in rainfall. In conclusion, in these case studies from semi‐arid Australia, we find no evidence to support the perception that, under the observed climatic condition and dust deposition rates up to 20 or 77 g m^?2 per month at Windarling Range and Barrow Island, respectively, dust accumulation on plants causes negative impacts.     

Diversity of tropical forest landscape types in Hainan Island, China

A novel landscape classification system was proposed in this study based on landscape ecological theory and the differentiation in climate, topography, soil, vegetation and land use mode. Five basic units (zone, tract, province, region and type) and two assistant units (sub and group) were used in this system. The tropical forest landscape in Hainan Island was regarded as a landscape province, belonging to global tropical forest landscape zone, Asiatic (oriental) tropical forest landscape tract and Chinese tropical forest landscape subtract. Based on the grade system of region, sub-region, type-group and type, this landscape province (Hainan Island) is divided into 6 landscape regions (east moist forest landscape, west semi-arid forest landscape, central-south mountainous forest landscape, tropical evergreen needle-leaved forest landscape, tropical bamboo landscape and tropical plantation landscape), 11 tropical forest landscape sub-regions represented by tropical lowland valley rain forest landscape, 26 tropical forest landscape-type groups represented by tropical lowland valley Dipterocarpaceae forest landscape, and 54 forest landscape types (FLT) represented by lowland valley Vatica mangachapoi forest. Generally, this classification system represents the landscape diversity of the tropical forest in Hainan Island. Further studies are needed to better understand the landscape diversity of Hainan Island.     

鄱阳湖南矶山湿地自然保护区的外来入侵植物调查与分析

为了解鄱阳湖南矶山自然保护区外来入侵植物的状况, 从2010 年至2014 年对外来入侵植物的物种种类、分布、传播等进行了调查。结果表明, 南矶山湿地保护区共有外来入侵植物32 种, 隶属于l8 科28 属, 其中菊科最多, 有8 种6 属;其次是苋科, 有4 种3 属, 绝大多数是草本植物;以原产地为美洲的最多, 有15 种, 其中来自北美的有9 种。对保护区造成严重危害的外来入侵植物有5 种, 分别为野燕麦(Avena fatua)、小飞蓬(Conyza canadensis)、野胡萝卜(Daucus carota)、裸柱菊(Soliva anthemifolia)和空心莲子草(Alternanthera philoxeroides), 危害较强的主要有7 种, 危害较轻的有20 种。对外来植物的入侵途径、规律与成因以及对生态环境造成的影响进行了讨论, 并提出了防治对策与建议。     

A new zoarcid, Lycodes mcallisteri, from eastern Arctic Canada (Teleostei: Perciformes)

A new zoarcid fish, Lycodes mcallisteri, is described on the basis of nine specimens (230–375 mm SL) from eastern Arctic Canada, Nunavut (Hudson Strait, 298 m; Cumberland Sound and Baffin Bay, 579 m). It resembles about 15 other Lycodes spp. in having a long tail and a "ventromediolateral" type of lateral line. It is distinguished from Arctic members of this group (Lycodes marisalbi, L. palearis, and L. sagittarius) by the high number of pectoral fin rays (22–23), short pelvic fins, low submental crests, and coloration (6–10 light patches dorsally). It resembles two Pacific species (L. macrochir and L. soldatovi) by the high number of pectoral fin rays, but differs by coloration, meristics, and shape of the pectoral fin. Received: April 13, 2000 / Revised: September 7, 2000 / Accepted: January 11, 2001     

木麻黄种子萌发的限制生态因子

成功的天然更新应同时具备三个条件:(1)种源数量充足、质量良好;(2)适宜种子萌发的微生境;(3)幼苗、幼树存活的生态条件。为进一步揭示海南岛木麻黄(Casuarina equisetifolia)海防林自身无法天然更新的障碍因子,该文对影响其天然更新的三个条件之一的种子萌发条件进行了研究,并探讨了不同的生态因子,如木麻黄化感、土壤酸碱度、盐度、温度、基质类型、水分等对木麻黄种子萌发的影响。结果表明:(1)不同浸提物的不同浸提液浓度处理的种子萌发率与CK组无显著性差异。(2)设定范围内的pH、盐度和温度对木麻黄种子萌发率无显著影响。(3)不同浓度梯度PEG溶液处理的木麻黄种子萌发率存在显著性差异,且伴随PEG溶液浓度增加,木麻黄种子萌发率随之锐减。(4)不同基质及浇水频度对种子萌发率也具有显著影响。从综合PEG干旱胁迫、基质及浇水频度的结果可以发现,木麻黄种子抗旱能力较弱,对水分敏感。因此,水分是制约木麻黄种子萌发的主要限制因子,凋落物层及滨海沙土较差的保水性不同程度地制约了种子的萌发。     

西沙群岛东岛小军舰鸟繁殖种群的初步观察

2003年3-4月对西沙群岛的鸟类资源进行了考察,在西沙群岛的东岛发现小军舰鸟(Fregata minor)繁殖,为迄今所知该种在我国仅有的繁殖记录。野外观察共发现7个巢,其中5个巢中途毁损,另见幼鸟13只,非繁殖雄性个体2只。还观察到小军舰鸟与红脚鲣鸟相互影响的负面行为,如抢食、窃巢材等。调查结果显示,西沙群岛小军舰鸟分布范围现已缩小,而且种群数量显著下降。     

崇明东滩围垦堤内植被快速次生演替特征

崇明东滩湿地98大堤内的生态示范区由于人工排水而干涸,芦苇塘成为次生裸地,土壤条件发生变化,呈明显的旱化和盐渍化,植被群落结构呈典型的次生演替,适宜旱地的耐盐植物獐茅和碱蓬等先锋植物出现.文中分别于2003年秋季、冬季和2004年春季沿植被带对塘内各种植物的生物量、高度、密度等指标进行取样分析.结果表明,堤内植被群落已形成明显的带状獐茅草-獐茅草/碱蓬-碱蓬/芦苇-芦苇旱生植被群落.碱蓬在裸地中2003年秋季平均生物量达到415.4 g·m^-2、2004年春季为391.53 g·m^-2,成为裸地的优势种,并向芦苇中扩散,生物量和高度逐渐增加,密度逐渐稳定,表现出良好的生长趋势.     

中国大陆青冈分布区东缘大金山岛种群种子形态变异

在大陆青冈分布区东缘的大金山岛种群中按不同坡向取样,旨在揭示相对均一条件下青冈种子的形态变异及变异的来源,以从不同侧面研究环境对形态变异的作用。大金山岛种群青冈种子的长度、直径和重量分别为1.557±0.128cm、1.175±0.112cm、1.321±0.310g,处于青冈种子正常分布范围内。单颗种子的长度、直径符合正态分布,而重量则明显偏离正态分布。不同坡向青冈种子间差异很小,表明微地形的影响较小;种群变异的来源株内和株间约各占一半,说明种子表型具有一定的可塑性,主要由于种子处于植株不同部位的缘故。     

崇明东滩南部河口盐沼植物群落种间关系的数量分析

对崇明东滩南部盐沼植物群落样方进行调查,基于现有17种高等植物,特别是8种常见植物的2×2联列表和植被盖度值,利用方差比率法、χ²检验以及Spearman秩相关分析对物种关联性和相关性进行分析.结果表明: 方差比率(VR=0.61)的检验统计量W=48.61,落在 χ² 2个临界值区间之外,因此该区域盐沼植物群落内植物整体关联度表现为显著负相关;依据各优势植物对环境的适应方式和生境的主导因素,参考Spearman秩相关分析的结果,将它们划分为4个生态种组: 芦苇、糙叶苔草-藨草-水莎草、互花米草-海三棱藨草、白茅-稗草.崇明东滩南部盐沼植物群落种间关系复杂,群落表现极不稳定,植物对于环境影响较为敏感.在明确物种之间关系的基础上,针对海三棱藨草的分布现状提出了相应种群的保护措施和建议.     

海南岛黎母山四眼斑水龟对春季生境的选择性

2004年3—4月,在海南岛黎母山采用系统抽样法对四眼斑水龟春季生境选择进行了初步研究。在海拔170～1170m设196个研究样点,共1392个笼捕日。其中在海拔170～470m的26个布笼点共捕获四眼斑水龟36只,而在海拔470～1170m未捕获到四眼斑水龟。采用Kruskal Wallis检验,对海拔500m以下四眼斑水龟利用样地(n=26)和海拔500m以上的对照样地(n=26)的生态因子差异显著性进行检验。结果表明,两类样地的海拔、植被类型、植被盖度、落叶厚度、土壤类型、坡度、水面宽、水深、水面流速、基底类型、露石率、食物丰度、干扰距离13个生态因子差异均显著,仅石洞数目差异不显著。说明海拔500m以上和以下的环境差异较大。主成分分析结果表明,影响四眼斑水龟生境选择的主要生态因子依次为海拔、干扰距离、植被盖度、土壤类型、水深和落叶厚度。而植被类型、食物丰度、露石率、基底、石洞数目、坡度、水面宽和水面流速8个生态因子的影响不明显。保护好近河岸植被和提高当地群众对龟类的保护意识对四眼斑水龟的保护十分重要。