Dynamics ofBetula ermanni population in subalpine vegetation in Changbai Mountain, Northeast China

Betula ermanni population was divided into three groups: the upper population (2 000–2 200 m), the middle population (1 700–2 000 m), and the down population (1 400–1 700 m) in Changbai Mountain. The dynamics ofBetula ermanni populations in subalpine vegetation are studied and the population life table, fecundity schedule, survival curves, age structure, and fecundity curves were established. The results showed that the, middle population is obviously, the transition from the upper population to the down population. This project is supported by Chinese Academy of Science Responsible editor     

北川不同海拔珙桐种群年龄结构研究

采用树木年代学的方法,按照珙桐的分布特点分海拔下限（1400 m～1500 m）,中部（1 600 m～1 700 m）,上限（1 800 m～1 900 m）,研究不同海拔梯度下北川珙桐种群的年龄结构,结果表明：海拔上限珙桐年龄结构偏大,缺乏幼苗及30 a～40a的个体;在海拔中部,30 a～40 a的个体占的比例较大,争夺空间和资源的能力更强;海拔下限的实生幼苗较多.在中部海拔分布的珙桐较多,且年龄结构集中在30 a～40 a之间,低海拔的种群特征是以幼苗为优势,而高海拔面有的幼苗却很少,表明海拔对珙桐种群年龄结构有重要的影响.     

Forest structure, diversity and regeneration in unburnt and burnt Anogeissus latifolia forests in Garhwal Himalayas

The present study was carried out at two different gradients of unburnt and burnt Anogeissus latifolia forest sites in the Garhwal region, India. At each gradient, the unburnt and burnt forest sites were further categorized into three different elevations, i.e., lower (700 m), middle (850 m) and upper (1000 m). At each elevation, the density of trees, saplings and seedlings was higher at the unburnt sites except for trees at the upper elevation which was higher at the burnt sites. The total basal area of each layer of forest was also higher at the unburnt sites. The study revealed that the lower number of saplings and seedlings at the burnt forest sites might be due to the effect of fire. Most trees in the lower dbh classes were affected by forest fire at the burnt sites which reduced the total density and total basal area of the trees compared to the unburnt sites. The diversity of trees increased with increasing elevation. However, the diversity of saplings and seedlings reduced with increasing elevation.     

坡位对大青杨生长影响的初步分析

通过对同一造林地3种不同坡位的大青杨(Populus ussuriensis)人工林生长情况进行的调查与分析,结果表明:3处位置即坡下位、中位、上位(海拔分别为700m、750m、800m)的大青杨树高和胸径生长量均有显著性差异;中位(海拔750m)处树高和胸径生长量最高,极大值均出现在此区域。因此,建议营造大青杨人工林应尽量选择坡中位。     

民勤沙井子地下水对荒漠植被演替的影响

基于对民勤沙井子地区不同时期植被调查数据,研究了不同群落自然植被在地下水影响下的植被演替过程,结果表明:自20世纪80年代中期以后,沙井子地区地下水位和水矿化度不断下降,地下水位由1988年的9m降至2015年的24.62m;水矿化度由1963年的2.93g·L~(-1)降至2015年的0.78g·L~(-1);随着地下水位的下降,植被向旱生方向演替;水矿化度高低直接影响植被的种类。     

粤北次生常绿阔叶林土壤有机碳分布特征研究

文章研究了粤北天井山林场2 hm2样地内土壤有机碳的分布特征及随土层、土壤理化性质的变化.结果表明:(1)0 ～25 cm土壤密度均值为(0.76±0.02) g/cm3,土壤有机碳平均质量分数为( 32.29±1.66) g/kg;25～50cm土壤密度均值为(0.96±0.02) g/cm3,土壤有机碳平均质量分数...     

藏东南嘎隆拉和墨脱河谷蚂蚁群落研究

[目的]为了揭示藏东南地区蚂蚁群落的生态学规律,对藏东南嘎隆拉和墨脱河谷不同样地的蚂蚁群落进行了调查研究,揭示藏东南地区蚂蚁多样性。[方法]采用样地调查法和手拣法进行调查;利用Estmaete S 9.1.0程序对数据进行处理,分析抽样充分性;利用多样性分析法,分析了蚂蚁群落的组成、优势种、物种多样性、群落均匀度及群落相似性等群落特征。[结果]合计发现蚁科Formicidae昆虫8亚科,45属,96种。分析发现,不同植被类型优势种和稀有种组成不同,稀有种较多。低海拔区域的沟谷雨林和常绿阔叶林蚂蚁优势种具有明显的热带和亚热带特征。多样性分析发现,各样地中的蚂蚁群落物种丰富度0 42种,个体密度0.0 1 805.6头·m-2,多样性指数02.285 5,均匀度指数0.251 0 0.873 6,优势度指数0.147 0 1.000 0。其中海拔1 200 m沟谷雨林的蚂蚁物种丰富度最高(42种);海拔1 450 m季风常绿阔叶林的多样性指数最高(2.285 5),优势度最低(0.147 0);海拔2 960m高山松林均匀度指数最高(0.873 6);高海拔的针叶林蚂蚁物种丰富度和多样性均最低,优势度最高。北坡分布的物种稀少,南坡物种丰富;群落相似性系数表明不同海拔和植被的蚂蚁群落间差异显著。[结论]嘎隆拉和墨脱河谷生境存在明显差异,蚂蚁群落的物种数目、个体密度、多样性指数和均匀度指数总体呈现随海拔升高和植被的更替而降低的规律,但在南坡下部和中部出现2个峰值,分别为热带和温带物种的聚集群,表现出多域效应现象(Multi-Domain Effect)。植被、海拔和坡向对蚂蚁物种的分布和多样性影响深刻。     

Effect of elevated [CO(2)] and varying nutrient application rates on physiology and biomass accumulation of Sitka spruce (Picea sitchensis)

Sitka spruce (Picea sitchensis (Bong.) Carr.) seedlings were supplied with solutions containing nitrogen (N) at 0.1 x or 2 x the optimum rate (low-N and high-N supply, respectively) and grown either outside in a control plot or inside open-top chambers and exposed to ambient (355 &mgr;mol mol(-1)) or elevated (700 &mgr;mol mol(-1)) CO(2) concentration ([CO(2)]). Gas exchange measurements, chlorophyll determinations and nutrient analysis were made on current-year (< 1-year-old) shoots of the upper whorl after the seedlings had been growing in the [CO(2)] treatments for 17 months and the nutrient treatments for 6 months. Total seedling biomass and biomass allocation were assessed at the end of the experiment. Nutrient treatment had a significant effect on the light response curves, irrespective of [CO(2)] or chamber treatment; seedlings supplied with high-N rates had higher net photosynthetic rates than seedlings supplied with low-N rates. The degree of photosynthetic stimulation in response to elevated [CO(2)] was larger in seedlings receiving high-N rates than in seedlings receiving low-N rates. Light-saturated net photosynthesis of seedlings grown and measured in elevated [CO(2)] was 26% higher than that of seedlings grown and measured in ambient [CO(2)]. There was no significant effect of [CO(2)] or chamber treatment on the CO(2) response curves of seedlings receiving High-N supply rates. In contrast, analysis of the CO(2) response curves of seedlings receiving Low-N supply rates showed acclimation to elevated [CO(2)]. Both maximum rate of carboxylation (V(cmax)) and maximum electron transport capacity (J(max)) were lower and J(max)/V(cmax) higher in seedlings in the elevated [CO(2)] treatment. There was no effect of elevated [CO(2)] on stomatal conductance, although it was highly dependent on foliar [N], ranging from ~60 mmol m(-2) s(-1) at ~1.5 g N m(-2) to 200 mmol m(-2) s(-1) at ~5 g N m(-2). In the high-N and low-N treatments, foliar N concentration was 10 and 28% lower in seedlings grown in elevated [CO(2)] than in seedlings grown in ambient [CO(2)], respectively. There was no [CO(2)] effect on foliar phosphorus concentration ([P]). Chlorophyll concentration increased with increasing N supply in all treatments. There was no significant effect of elevated [CO(2)] on specific leaf area. Chlorophyll concentration expressed either on an area or dry mass basis for a given foliar [N] was higher in seedlings grown in elevated [CO(2)] than in seedings grown in ambient [CO(2)]. Elevated [CO(2)] increased total biomass accumulation by 37% in seedlings in the high-N treatment but had no effect in seedlings in the low-N treatment. There was a proportionally bigger allocation of biomass to roots of seedlings in the elevated [CO(2)] + low-N supply rate treatment compared with seedlings in other treatments. This resulted in a reduction in aboveground biomass compared with corresponding seedlings grown in ambient [CO(2)].     

四川卧龙岷江冷杉林小流域土壤水分的时空分布特征及变异性

本文应用CNC503DR型中子土壤水分仪,在四川卧龙亚高山暗针叶林生态系统定位站,研究了林分和小流域尺度上岷江冷杉林土壤水分的时空分布特征及变异性。结果表明：研究期间,小流域土壤平均容积含水量在0.59~0.66之间,不同群落类型之间,差异比较明显,且随时间的变化规律不同;小流域内土壤剖面的平均容积含水量在0.52~0.77之间,平均值为0.60,土壤表层最高,45 cm深度最低;随着海拔升高,土壤含水量增加,但超过3 700 m则减少;不同坡向,土壤含水量在0~30 cm土层半阴坡高于半阳坡,30 cm以下土层则相反;不同坡位,土壤含水量下坡最高,其次是中坡,上坡最低;小流域土壤水分变异系数在0.217 6~0.409 8之间,不同群落类型之间差异显著,随着土层剖面深度增加而减小,随着海拔升高而减小,半阴坡高于半阳坡,下坡大于中坡和上坡。     

16年生尾巨桉小初植密度生长规律研究

以小密度667株.hm-2在3个立地指数22、24和26条件下,16年生林分生长结论为：（1）立地指数22、24和26达到中大径材培育目标的时间和年均生长量指标分别为10 a、8 a和7 a,年均生长量分别为21.6、27.2和31.1m3.hm2。（2）胸径生长和分布：胸径生长量随着时间的推移逐年变小,前2 a胸径每年生长超过4 cm,第3年超过2cm,4~6年超过1cm,以后越来越小,但在16 a的观测过程中,每年都稳定超过0.4 cm;在生长前期,2年生时,只有2~3个径阶;到6年生时,径阶增加到7个;到16年生时,径阶增加到10~11个（。3）平均高生长量随着时间的推移逐年变小,前3 a树高生长均超过3 m;第4~5年超过2 m,5~10 a超过1 m,以后越来越小,但在16年的观测过程中,每年稳定超过0.6 m。（4）蓄积量生长的高峰值都出现在第4年,且峰值都很大,指数22、24和26的峰值分别为43.3、52.23和54.69 m3.hm-2,为平均生长量的2倍,峰值过后年生长量迅速下降,第1年下降超过10 m3.hm-2,第2年下降7 m3.hm-2,以后逐年下降,但降幅收窄;指数22、24和26的连年与平均蓄积生长曲线的交叉点均出现在第7年。     

安徽查湾自然保护区甜槠林林隙森林物种多样性研究

采用样线法调查研究区内林隙分布,共获得36个林隙,大小不同林隙内植物种类组成表现出一定差异,大林隙(300~400m2)乔木树种18种,灌木、草本植物28种;小林隙(<100m2)乔木树种13种,中林隙(100~200m2)11种,两者灌木及草本植物均21种。大、中林隙内乔木树种以江南桤木居多,小林隙中暖木和甜槠占优势;3个林隙中灌木均以青栲幼苗占绝对优势,表明青栲将有可能进入林冠层而逐渐成为优势树种。林隙内乔木树种种数、丰富度指数均大于非林隙,均匀度小于非林隙;灌木、草本植物具有同样规律。乔木树种物种多样性以大林隙最高、中林隙最低;不同面积林隙SW多样性指数、均匀度指数依次为:大林隙>中林隙>小林隙;生态优势度为:中林隙>大林隙>小林隙。灌木、草本植物物种数、丰富度指数表现出300~400m2面积的大林隙内达最大值,并随林隙面积的减小而减小,灌、草层植物多样性最大值也出现在大林隙中;生态优势度指数中林隙最大,小林隙最小。     

广东低山林下土壤理化特征分析

以广东南岭国家级自然保护区、广东蕉岭长潭省级自然保护区、广东肇庆市德庆三叉顶市级自然保护区低海拔(400～500 m)区域的森林土壤为研究对象,比较分析了土壤(分上层0～25 cm和下层25～50 cm)的自然含水量、土壤质量密度、pH、有机质(SOM)、有机碳(SOC)、全氮(TN)、速效氮(AvN)、速效磷(AvP)、速效钾(AvK)分布特征。结果表明:(1)南岭自然保护区、长潭自然保护区和三叉顶自然保护区之间的自然含水量、土壤质量密度、pH、SOM、SOC、TN、AvN、AvP、AvK差异极显著(P0.01);0～25 cm土层和25～50 cm土层的自然含水量、土壤质量密度、SOM、SOC、TN、AvN、AvK差异极显著(P0.01);(2)3个保护区中,只有南岭自然保护区0～25 cm土层的TN与AvN相关性显著(P0.05),其余保护区各土层的相关性都未达到显著水平(P0.05);(3)回归分析表明,0～25 cm土层与25～50 cm土层的pH在3个保护区中差异显著(P0.05),另外,南岭自然保护区的土壤质量密度、长潭自然保护区的土壤速效氮、三叉顶自然保护区的土壤全氮和土壤速效钾在0～25 cm土层和25～50 cm土层间差异极显著(P0.01)。     

Effects of rainwater harvesting on herbage diversity and productivity in degraded Aravalli hills in western India

Over-exploitation and rural growth have severely damaged native vegetations of Aravalli hills in Rajasthan, India. This study was conducted to evaluate the effects of different restoration practices (i.e., rainwater harvesting (RWH) and planting of tree seedlings) on improve- ment in soil water and nutrients and growth and biomass of herbaceous vegetation. Contour trench (CT), Gradonie (G), Box trench (BT), V-ditch (VD) and a control were imposed on 75 plots (each of 700 m 2 ) in natural slope gradient defined as <10%, 10% 20% and >20% slopes in 2005. Each plot had three micro-sites of 1-m 2 at up (USP), middle (MSP) and lower (LSP) part of the plot for observation in 2008. The existed gradient (due to soil texture and topographic features) of soil pH, EC, SOC, NH 4 - N, NO 3 -N and PO 4 -P in June 2005 between >20% to <10% slopes were decreased in 2008 after applying RWH techniques. Such improvement in soil status promoted vegetation growth and biomass in higher slope gra- dients. Soil water, species diversity and herbage biomass increased from USP to LSP, and RWH techniques had positive role in improving SOC, nutrients, vegetation population, evenness and growth at MSP. Despite of lowest SWC, regular rain and greater soil water usage enhanced green and dry herbage biomasses in 10% 20% and >20% slopes, compared with <10% slope. The highest diversity in CT treatment was related to herbage biomass, which was enhanced further by highest concentrations of SOC and PO 4 -P. Further, CT treatment was found to be the best treat- ment in minimizing biomass variance in different slopes. Conclusively, soil texture and topographic features controlled soil water and nutrients availability. Rainwater harvesting techniques increased soil water storage and nutrient retention and also enhanced vegetation status and biomass by minimizing the effects of hillslopes. Thus depending upon the site conditions, suitable RWH technique could be adopted to increase herb- age biomass while rehabilitating the degraded hills.     

秦岭中段华山松林健康评价研究

本实验以秦岭中段华山松林为研究对象,在秦岭中段的火地塘林区,按照不同的立地条件,设置26块20 m×20 m的标准样地,以生态服务功能为依据,从活力、组织结构、土壤因素、抵抗力4个方面22个指标入手,对秦岭中段华山松林生态系统健康状况进行健康评价.结果表明:秦岭中段的华山松林整体活力指标较低,大部分都处在20～35年之...     

九寨沟华西箭竹（Fargesia nitida）开花种群特征

2009年4月、7月对九寨沟自然保护区内各样地进行调查,只在鹰爪洞沟3 000 m以上的山坡中上部发现开花的华西箭竹种群分布。调查发现：开花竹种群为典型的下降型年龄结构,表现出明显的衰退种群的特点,约22%～29%的箭竹正在开花。平均花穗密度约为296朵.m-2,平均种子密度约为3 923粒.m-2。华西箭竹的花为顶生的总状花序,花穗颜色以绿色为主,黄色、黄绿色花也较多,偶见绿紫色花。单株花穗数约在10朵～19朵之间,单株种子数在约130粒～250粒之间。平均每朵花穗的种子数约为13粒。     

退化红壤物理性质的空间异质性的初步研究

采用地统计学的理论和方法,研究退化红壤区的土壤4种物理性质的空间异质性。变异函数分析结果表明:退化红壤的物理性质有中等程度的空间相关性,土壤容重与毛管孔隙度具有明显的空间异质性,在0～20cm土层深,有效变程尺度分别为700m和12650m,自相关部分的空间异质性为68.5%和73.6%,明显大于随机部分的空间异质性;在空间自相关范围内,土壤各物理因子的空间异质性有重要的密切关系。     

Comparative study on population age structures between Adenophora lobophylla and A, potaninii

IntroductionPlantnumberdynamicdependsonthenumberofbirth,death,emigrantandimmigrant(Pielou1977,Si1vertown1982).TheplantagestructureistheresuItofinteractionbetWeentheplantviabilityandtheenvi-ronmentalfactors(Grawley1991).Studyontheen-dangeredpfantpopuIationagestructureisverysig-nificantforappraisingthepopuIationdynamicandpopuIationdevelopingtendency.ltnotonlyexplainsthepopuIationstatusbutaIsoprovidesthescientificreferenceforconservation.Theworksontheendangeredplantpopulationdynamichavebeenca…     

四川白河自然保护区连香树的空间分布与种群特征

以四川白河自然保护区连香树为研究对象,采用访问法、样线法和样方法相结合,调查连香树的空间分布位点、种群特征和干扰因素。调查结果表明:保护区有连香树365株,适宜面积约1 995.46 hm2;海拔1 900～2 200 m区域的连香树株数占总株数的89.53%,尤其是海拔2 000～2 100 m分布最为密集(占43.01%);径级分布为纺锤形,自然更新差,种群呈不稳定状态,胸径在12～32 cm之间的有238株(占65.20%)。连香树主要分布区与传统耕作区和放牧区的重叠性高,林地转化成耕地及放牧践踏是连香树种群数量和栖息地下降的主要原因;减少人为干扰、就地保护与监测、建立天然母树园、种子繁殖和扦插是保护连香树种群的有效措施。     

The scale Nemolecanium graniformis (Wunn) (Homoptera: Coccidae) in Greece

The phenology and natural enemies of Nemolecanium graniformis (Wunn) (Homoptera: Coccidae) in infesting Abies cephalonica, were studied in Greece during 1998?–?1999. This oviparous species develops one generation per year in Central Greece (Attica) and overwinters as 2^nd instar nymph. Young adult females appear by the end of July, and the first instar nymphs by the middle of August. By the middle of October, the whole population of the scale is recorded as 2^nd instar nymphs. The parasitoids Coccophagus lycimnia (Walker), Coccophagus Westwood sp., Aphycoides Mercet sp. and the predator Exochomus quadripustulatus L. (Coleoptera: Coccinellidae), were observed as natural enemies of the scale. The average fecundity of N. graniformis was 188.4 eggs.     

不同林隙间伐对长白落叶松土壤物理性质的影响

以黑龙江省佳木斯市孟家岗林场的长白落叶松中龄林为研究对象,在2012年进行林隙间伐(5 m×5 m、7 m×7 m、10 m×10 m),并于2013年和2014年选择0～10 cm、10～20 cm、20～40 cm的土层进行取样,测定土壤的物理性质,其结果表明:林隙间伐能够改善长白落叶松中龄林土壤的物理性质,林隙7 m×7 m的林分,改善了土壤的松散程度,使容重减小,提高土壤毛管孔隙度,持水能力增强。