保安湖沙塘鳢的食性、繁殖、年龄及生长的研究

保安湖沙塘鳢１冬龄成熟,雌雄比１：１．３４,４月初至６月中旬繁殖;个体绝对繁殖力５４０—１９４３ｅｇｇ（１１５４±３１４ｅｇｇ）。渔获物中以体长８．０—１４．０ｃｍ,体重１０．０—４０．０ｇ,２、３龄个体为主。体长－体重关系为Ｗ＝０．０２１２９Ｌ３.０５８５。３龄前生长较快;雄鱼略快于雌鱼。肥满度冬春季较高,最高在３月。体长和体重与年龄的关系可用Ｂｅｒｔａｌａｎｆｆｙ生长方程描述,参数分别为：雌鱼Ｌ∞=１５．２９ｃｍ,ｋ＝０．４０７２,ｔ０＝０．１５９６,Ｗ∞＝８４．９ｇ;雄鱼Ｌ∞＝１６．７１ｃｍ,ｋ＝０．３７３６,ｔ０＝０．１０９５,Ｗ∞＝１１８．５ｇ;体重生长拐点年龄和拐点体重雌鱼分别为２．８６ａ和２５.１ｇ,雄鱼３．１３ａ和３５．４ｇ。     

深圳湾大弹涂鱼种群结构与生殖特征

本文探讨了深圳湾大弹涂鱼种群结构和生殖特征。结果表明：该种群以１、２龄鱼组成为主,３龄鱼极少,表明种群结构简单,体长与体重的相关曲线方程为Ｗ＝４．１６１８×１０－５Ｌ２．７４５１（ｒ＝０．９５７６）。雌雄性比为３：２。一龄鱼开始性成熟。雌鱼性成熟最小生物学体长为６２ｍｍ,雄鱼为５９ｍｍ。个体绝对生殖力波动于１９５６—１４０５３粒,平均７２９３粒;个体相对生殖力Ｆ／Ｌ：２９．５—１００．５粒／ｍｍ,平均７９粒／ｍｍ;Ｆ／Ｗ：５１１．０—８０４．９粒／ｇ,平均７５２粒／ｇ。４—６月为繁殖盛期,７—８月为繁殖末期。雌性周年月平均成熟系数（ＧＳＩ）变动范围为０．２７％—４．３６％。大弹涂鱼在一个生殖季节中只能产卵一次,属于一次性排卵类型。     

半荒漠藻结皮中藻类的种类组成和分布

对宁夏沙坡头半荒漠藻结皮中２２种藻（其中蓝藻１０种,绿藻４种,硅藻６种,裸藻２种）进行了分离、鉴定;利用土壤磨片和电子探针揭示了藻体与基质间的结合方式;通过光镜、扫描电镜观察,从８个层次研究了藻类在结皮中的分布,并发现它们在微米间也呈“层片”分布规律,藻结皮由表及里依次为无机矿物质保护层（ｃａ．０．０２ｍｍ）、富藻层（ｃａ．０．０２～２．５ｍｍ）及疏藻层（２．５～５．０ｍｍ）;藻丝皮由表及里依次为     

荷兰鸢尾(Iris xiphium L. var. hybridum)的组织培养

取荷兰鸢尾（ＩｒｉｓｘｉｐｈｉｕｍＬ．ｖａｒ．ｈｙｂｒｉｄｕｍ）鳞茎片不同部位外植体块,接种于附加不同激素配比的基本培养基上,其中取自鳞茎片基部外植体块２ｍｍ×２ｍｍ×２ｍｍ,培养基为ＭＳ＋ＢＡ１．０ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ的不定芽诱导率为最高（７０％）;最理想的增殖培养基为ＭＳ＋ＢＡ２．０ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ。不定芽直径４～５ｍｍ,培养基为ＭＳ＋ＢＡ０．２ｍｇ／Ｌ＋ＮＡＡ０．５ｍｇ／Ｌ有利于不定根的发生,诱导生根率达８３３％。试管苗不经练苗可直接出瓶,移栽于泥炭∶田土∶河沙＝１∶１∶１（Ｖ／Ｖ）的基质中。     

五台山草地自然保护区土壤中钴的含量分布及影响因素

研究五台山６种主要土壤类型中全钴的含量分布,并对影响其含量分布的一些主要因素进行了分析。结果表明：①五台山土壤中全钴含量范围为１２．７７～２３．３９ｍｇ／ｋｇ,平均含量为１７．３８ｍｇ／ｋｇ,高于全国及世界土壤中钴的平均含量。影响土壤全钴含量的主要因素是土壤母质。②相关分析表明,五台山土壤中全钴含量与全铁、全铜含量呈极显著正相关,且全钴含量与全铜含量关系更为密切;而与土壤有机质、ｐＨ、１～０．０１ｍｍ、０．０１～０．００５ｍｍ、０．００５～０．００１ｍｍ、＜０．００１ｍｍ的土粒含量及全锰含量无明显的相关性。③五台山土壤中全钴含量高于土壤中钴的临界水平     

新疆鹅喉羚的种群结构

１９９２年８～９月和１９９３年９月,作者在新疆北部鹅喉羚北疆亚种（ＧａｚｅｌｌａｓｕｂｇｕｔｔｒｏｓａＳａｉｒｅｎｓｉｓ）分布区（天山以北）设置１９条样带,总长８１８ｋｍ,观测点至动物的平均垂直距离２４８．３ｍ,面积４０５．８ｋｍ２的调查统计,见鹅喉羚６２群次,共２２１只。样带中动物的平均密度为０．７１±０．１７只／ｋｍ２。对能判别性别和成幼的１６条样带中的３７群次１１３只统计,雌：雄＝１：１．０５,成：幼＝２．４：１。对８条样带中的１６群次５０只统计,母：仔＝１：１．４。１９９３年２月和１０月,我们还在新疆南部鹅喉羚南疆亚种（Ｇ．ｓ．ｙａｒｋａｎｄｅｎｓｉｓ）分布区（天山以南）,设置８条样带,长２３０ｋｍ,平均垂直距离２９９ｍ,面积１１６ｋｍ２的调查统计,见鹅喉羚１７群次５１只,平均密度０．５７±０．２６只／ｋｍ２。     

青年男性高原移居者最大摄氧量计算公式的推导

最大摄氧量（Ｖｏ２ｍａｘ）是评价人体体力的重要指标,其测定方法分直接法和间接法两种。目前所推导的间接计算公式都是在平原、或是在进入高原初期推导的,不适用于高原习服人群。本研究采用逐步回归的方法,推导出移居高原７－２７个月、不同高度的青年男性Ｖｏ２ｍａｘ间接计算公式。在海拔３６８０ｍ地区,Ｖｏ２ｍａｘ（Ｌ／ｍｉｎ）＝１．１５３１＋０．００７３２７身高（ｃｍ）＋０．０１６１３体重（ｋｇ）－０．００５８８３晨脉（ｂ／ｍｉｎ）－０．００４５３４运动心率（６０Ｗ,６／ｍｉｎ）,Ｒ＝０．７４５,Ｐ＜０．０１,ＳＳ＝３．７７９９;或Ｖｏ２ｍａｘ（Ｌ／ｍｉｎ）＝１．２１８６＋０．０１９８４体重（ｋｇ）＋０．０７２５９肺活量（Ｌ）－０．００６６５９晨脉（ｂ／ｍｉｎ）,Ｒ＝０．７１３,ｐ＜０．０１,ｓｓ＝３．９６３６。在４３５０ｍ地区,Ｖｏ２．ｍａｘ（Ｌ／ｍｉｎ）＝０．４９１７＋０．０１６８７体重（ｋｇ）＋０．１１０９肺活量（Ｌ）＋０．００１９８３屏气时间（Ｓ）,Ｒ＝０．７８１,Ｐ＜０．０１,ＳＳ＝２．１３５６。计算值与实测值比较,变异系数在１３％以内,结果准确可靠,适用于青年男性高原习服移居者。     

汉江中下游水生植物多样性及南水北调工程对其影响

１９９７—２０００年对汉江中下游８个江段水生植物种类组成、分布、生物量做了调查。汉江中下游共有水生植物１８科２２属３４种,以世界广布种为主,Ｒ／Ｔ值为０．６７。中游以沉水植物群落为优势,建群种为轮叶黑藻（Ｈｙｄｒｉｌｌａ　ｖｅｒｔｉｃｉｌｌａｔａ）、穿叶眼子菜（Ｐｏｔａｍｏｇｅｔｏｍ　ｐｅｒｆｏｌｉａｔｕｓ）和微齿服于荣（Ｐ．ｍａａｃｋｉａｎｕｓ）;下游主要为挺水植物群落,建群种为东方香蒲（Ｔｙｐｈａ　ｏｒｉｅｎｔａｌｉｓ）和芦苇（Ｐｈｒａｇｍｉｔｅｓ　ｃｏｍｍｕｎｉｓ）,生物量为５７．５—２１００ｇ／ｍ＾２;α－多样性在丹江口最高（０．５４６）,老河口次之（０．５１７）,仙桃员低（０）;生活型多样性在中游丹江口最大（０．４０２）;β—多样性在时间梯度６—８月份在所有样点β＝０,水平梯度β＝０．７９,垂直梯度β＝１．４８;γ—多样性在汉江中游为２９种,在下游为１０种。中游地区水生环境适合水生植物生长,而下游人类活动导致水环境趋于恶化限制了水生植物分布。     

东灵山地区大气降水特征及森林树干茎流

对东灵山地区大气降水特征及森林树干茎流进行了研究,结果表明：年降水量大部分集在６－９月份,日降水以量级低于５．０ｍｍ的小雨较多,单次降水以雨强小于２．０ｍｍ的阵性降水为主,单株树木的干流量以辽东栎（３０．３ｍｍ）最大,棘皮桦（２．９ｍｍ）最小;两个生长季各林分的干流深是;辽东栎林６６．６８ｍｍ,３５．１９ｍｍ;落叶松林４３．７６ｍｍ,２３．１２ｍｍ;混交林３２．７７ｍｍ,１７．３６ｍｍ;油松林２２     

平菇丰收一号高产特性的研究

通过野生种分离选用的平菇丰收一号,染色体数为９（ｎ＝９）,菌丝生长速度比一般品种快２—３４ｃｍ／ｈ,平均投料０．５ｋｇ（块）产鲜菇０．６～２．５ｋｇ,个别单株重１０～２０ｋｇ左右,生物效率１００～１５０％,高者达２００％以上,是一种高产优质、适应性强的新菌种。     

长江口东滩湿地芦苇生境大型底栖无脊椎动物群落结构的月动态

2015年5月至2016年4月对长江口东滩湿地芦苇生境的大型底栖无脊椎动物群落结构进行监测,分析了该生境下底栖动物群落物种组成和多样性的月变化.结果表明: 芦苇株高和盖度均在3—8月逐渐增大,9月后逐渐降低;芦苇密度和地上生物量(干质量)均在7月达到最大值.调查期间,共发现大型无脊椎底栖动物20种(包括2种鉴定到属,2种鉴定到科).其中,腹足纲种类最多,有11种(包括1种鉴定到属);软甲纲有5种;昆虫纲和多毛纲均只有2种.以緋拟沼螺、堇拟沼螺和尖锥似蟹守螺等为主要优势种.从生活型来看,底上附着型种类数最多(11种),其次为穴居型(5种)和底内型(4种).大型底栖动物密度和生物量存在明显的季节或月变化,夏季(8月)出现全年最高值.Margalef物种丰富度指数(D)和Shannon指数(H)月份间差异显著,Pielou均匀度指数(J)月份间差异不显著(除11月).大型底栖动物群落在42%相似性水平上划分为3个群聚.从非度量多维标序(nMDS)排序图可知,5月、10—11月与其他月份差异较大.水温、芦苇地下生物量和盐度等环境因子对于底栖动物密度变化具有一定影响,但未达到显著水平(P>0.05).受人类活动的持续影响,长江口东滩湿地芦苇生境底栖动物群落物种多样性有所下降,芦苇生境价值急需重视.     

Effects of harvesting <Emphasis Type="Italic">Cyperus papyrus</Emphasis> in undisturbed wetland,Lake Naivasha,Kenya

In many parts of the world and especially in Africa, wetland plants are harvested to support livelihoods. As such, removal of biomass may have an impact on the standing biomass which could affect primary productivity, a fundamental biological process supporting trophic levels. In this study, the effects of harvesting on aerial biomass and shoot regeneration of Cyperus papyrus L. was investigated following 6 and 12 monthly harvesting regimes compared with un-harvested controls over a period of 3 years in an undisturbed site of Lake Naivasha. Our study revealed that the 6 monthly harvesting regime significantly affected aerial biomass production, culm (stem) density, culm diameter, culm height and clonal young shoot regeneration compared to the 12 monthly regime and the controls. This study recommends a harvesting regime that allows an adequate period for a full cycle of C. papyrus stems from young to senescence stage.     

Adapting a patch model to simulate the sensitivity of Central-Canadian boreal ecosystems to climate variability

Aim To investigate effects of within-season and interannual climate variability on the behaviour of boreal forest ecosystems as simulated by the FORSKA2 patch model. Location Eleven climate station locations distributed along a transect across the boreal zone of central Canada. Methods FORSKA2′s water balance submodel was modified to enable it to behave more realistically under a varying climate. Long-term actual monthly time-series of temperature and precipitation data were detrended and used to drive the modified model. Long-term monthly averages of the same detrended data were used to drive the unmodified model. Results Modifications created significant improvements when simulating species composition at sites in boreal Canada. Simulated forest biomass values were slightly higher than those obtained from the unmodified model using averaged climate records, but resembled the observed distribution of vegetation more closely. Main conclusions Modified FORSKA2 suggests that boreal forest composition and distribution may be more sensitive to changes in monthly rainfall data than to changes in temperature. Climate variability affects seasonal water balances and should be considered when using patch models to forecast vegetation dynamics during and following a period of climate transition. The modified model provided improved representation of the latitudinal trend in spatially averaged biomass density in this region.     

Population densities and community structure of birds in broadleaved woodland in the lowveld of Swaziland

Population density and community structure of birds was studied at three sites in broadleaved (combretaceous) woodland in the lowveld of Swaziland. Birds were surveyed monthly using a standard point count technique. A total of 94 species of birds was recorded. Species richness at the three sites ranged between 57 and 73 species. Population density was similar at the three sites and ranged from 11.8 to 13.9 birds/ha. Biomass of birds was also similar at the three sites. Resident birds only accounted for 49% of all species, but made up 85% of the individuals and 82% of the biomass. There was a relatively large number of vagrant species, but they only accounted for 10% of the individuals and 14% of the biomass. Species richness of intra-African and Palaearctic migrants was low, and they contributed little to the bird density or biomass. In terms of diet, most birds were insectivorous, with mixed diet and granivorous species contributing approximately equally to biomass. Frugivorous species and raptors contributed little. The avifauna of broadleaved woodland in Swaziland is compared with that of other broadleaved woodlands in southern Africa and with that of Acacia savanna in Swaziland. Broadleaved woodland in Swaziland appears to support an avifauna which is depauperate compared to that of Acacia savanna, but not distinct from it.     

呼伦贝尔沙地樟子松人工林乔木层固碳速率及其对气象因子的响应

以呼伦贝尔沙地樟子松人工林为对象,利用树木年轮学方法和解析木法,推算过去41年的樟子松林生物量、碳密度和固碳速率,并分析固碳速率与月均气温、月均最低温、月均最高温、月降水量、月均大气相对湿度等气象因子的关系。结果表明:樟子松林碳密度随着林龄的增加而增加,碳密度从1977年的2.58 t·hm^-2增加到2017年的87.97 t·hm^-2;樟子松林固碳速率的年际差异较大,总体上呈现出先增加后减小,最终趋于稳定的趋势,多年固碳速率为1.37~3.21 t·hm^-2·a^-1,平均为2.13 t·hm^-2·a^-1;樟子松林固碳速率与上一年和当年生长季的降水呈正相关,与非生长季降水呈负相关,特别是与上一年12月和当年3月降水量呈显著相关;与上一年和当年8—9月的月均湿度显著正相关;与上一年及当年生长季的月平均气温、月均最低温和月均最高温呈显著或极显著负相关;樟子松林固碳能力同时受温度和降水的影响,但温度的影响大于降水的影响,在未来该地区气候暖干化的变化趋势下樟子松林固碳潜力可能会降低。     

Distribution, life cycle and population dynamics of the aquatic enchytraeid Propappus volki (Oligochaeta) in an English chalkstream

Propappus volki was recorded in Dorset chalk streams from gravel substrata where it represented up to 88% of the oligochaete fauna. It was absent from silted sediments associated with marginal and submergent macrophytes. P. volki showed an annual life cycle with a peak of mature individuals in the period April to June, whilst young worms were most abundant after July. The mean monthly biomass in Bere Stream was estimated to be 0.29–0.45 g wet weight m⁻² and the highest mean density was 5465 m⁻² in April 1979.     

Temporal and spatial structure in the suprabenthic community of a shallow estuary (western Portugal: Mondego river estuary)

The suprabenthic fauna of the Mondego river estuary (western Portugal) was sampled monthly between June 1996 and June 1997. Quantitative samples were taken, with a suprabenthic 500-μm mesh size net, at regularly spaced stations covering the entire south arm of the estuary. The diversity of the samples and the distribution of the species were assessed. Suprabenthic communities were identified using a divisive multivariate statistical technique and species composition, density and biomass of the dominant species of each community were compared among communities. Diversity was highest in the mouth of the estuary where density and biomass were lowest. Diversity decreased upstream and was lowest in the mid and inner estuary where density and biomass reached maximal values. Suprabenthic animals, mainly the mysid Mesopodopsis slabberi, reached high densities in inner and upstream stations, whereas the more seaward stations had lower densities but a higher number of species. The spatial patterns dominated over the temporal patterns.     

苏州工业园区水体浮游甲壳动物群落特征及其与环境因子的关系

于2012年6月至2013年5月,对苏州工业园区湖泊和河流水体的浮游甲壳动物组成及群落结构进行了研究,分析了浮游甲壳动物的密度和生物量的年度变化,探讨其分布与水体理化因子间的关系.结果表明：园区水体有枝角类6科12属24种,桡足类7科13属18种,其中短尾秀体溞、长额象鼻溞、汤匙华哲水蚤及近邻剑水蚤在不同水体中不同季节均为优势种.在湖泊水体和河流水体中,浮游甲壳动物的密度和生物量表现为夏、秋季较高,冬、春季较低,且在夏、秋季分别具有2个峰值.枝角类平均密度和生物量在河流水体中均高于湖泊水体,两者间均具有显著差异;桡足类的平均密度在河流水体和湖泊水体间差异不显著,而平均生物量要显著高于湖泊水体.湖泊水体和河流水体在溶解氧、pH、透明度、总溶解固体、盐度、总磷、总氮及铵氮含量上均存在显著差异;冗余分析表明无论是湖泊水体还是河流水体,多数浮游甲壳动物的分布与水温、盐度、化学需氧量(COD_Mn)和总磷等指数呈正相关,只有枝角类中的溞属、船卵溞属种类的分布与水体溶解氧、pH值及透明度呈正相关.     

Secondary production and condition index in Arca zebra (Mollusca: Vivaldia) in the Gulf of Cariaco, Venezuela

Production and condition index of a turkeywing (Arca zebra) population were studied from August 1984 to August 1985 in Pariche, Cariaco Gulf, Venezuela. Production was studied through bimonthly collections using a method designed for populations with continuous reproduction and indistinguishable age classes. The population distribution was stable with a mean density of 37 ind.m-2. A production of 131.61 g dry weight m-2 year-1 was calculated from data on density, biomass and weight increase along the year. Highest production was between February 1985 and August 1985 (65%) and concentrated in individuals 60.00-79.95 mm long (45.73%). There was large seasonal variation in the mean monthly condition index (IC = (Ps/Ph) x 100) in the two size classes examined: it reached a maximum in July 1985 (26.84%) and a minimum in January 1985 (16.31%).     

内蒙古大青山华北落叶松人工林乔木层碳密度年增量与气象因子的关系

以内蒙古大青山华北落叶松人工林为研究对象，通过树木年轮法和异速生长方程法，计算华北落叶松人工林生物量、碳密度及其年增量的年际变化，并分析碳密度年增量与气温、降水、湿度等气象因子的关系。研究发现：华北落叶松人工林碳密度随着林龄增加的变化曲线可用逻辑斯谛生长方程拟合，在1979—2016年，碳密度由1.05 t/hm~2增加到76.83 t/hm~2。华北落叶松人工林碳密度年增量存在显著的年际差异，总体上呈波动性的“慢-快-慢”趋势，碳密度年增量最高达到3.72 t hm^-2 a^-1,多年平均为2.05 t hm^-2 a^-1。华北落叶松人工林碳密度年增量与上年6月和当年6—8月的降水量显著正相关，与上年11月降水显著负相关；与上年11—12月、当年2月和12月的温度和大气相对湿度分别呈正、负相关；与上年7月、9月及当年8—9月的温度保持显著或极显著正相关。研究表明，温度、湿度和降水主要通过生长季的长短和土壤可利用水分及冬季的雪害冻害影响华北落叶松人工林的碳汇潜力，在未来该地区升温增湿的气候变化趋势下华北...