内蒙古草原三种植物群落中狭翅雏蝗造成的牧草损失(英文)

狭翅雏蝗Chorthippus dubius是我国北方草原的重要蝗种之一,在大发生年对牧草的威胁很大。它对牧草的损失至今尚无较准确的定量估算。本文通过测定不同发育阶段狭翅雏蝗的取食率、掉落毁损率,结合野外自然种群数据,对内蒙古草原三种植物群落中狭翅雏蝗造成的牧草损失进行了估测,并对三种草场蝗虫的经济阈值进行了计算。主要研究结果如下: 1.狭翅雏蝗对羊草、冷蒿、大针茅的取食率相似;取食率与虫体体重存在显著的线性相关。 2.狭翅雏蝗每个个体在一生中平均造成牧草损失487.55—784.4mg(干重),每日消耗与浪费的牧草为7.64—11.45mg。 3.狭翅雏蝗种群造成的牧草损失在冷蒿群落、羊草-大针茅-羊草群落、羊草-大针茅群落分别为1.52,1.65,0.76g/m,占地上初级生产量的2.96％、1.18％、0.42％,表现为越退化的草场,狭翅雏蝗对牧草的压力越大。其累积损失量的季节程式可以刚logisuc方程拟合。 4.狭翅雏蝗的经济阈值在羊草、羊草+大针茅+冰草、冷蒿草原分别为每平方米18.5、19.4、11.8头四龄为主个体。     

内蒙古草原三种植物群落中狭翅雏蝗造成的牧草损失

狭翅雏蝗(Chorthippus dubiua)是我国北方草原的重要蝗种之一,在大发生年对牧草的威胁很大。它对牧草的损失至今尚无较准确的定量估算。本文通过测定不同发育阶段狭翅雏蝗的取食率、掉落毁损率,结合野外自然种群数据,对内蒙古草原三种植物群落中狭翅雏蝗造成的牧草损失进行了估测。主要研究结果如下:     

中国典型草原放牧草场蝗虫为害损失及经济阈值的估算(英语)

传统上估算蝗虫在放牧草场为害损失的方法几乎都是用来测定对牧草秋季产量的影响,而实际上,在估算放牧草场蝗虫为害损失及经济阈值时,牧草的现存量而非秋季产量是更应考虑的因素.本文提出了一种适合测定蝗虫对牧草现存生物量影响的新方法,即野外挂笼饲养与蝗虫种群动态相结合的估算方法,并在此基础上组建了放牧草场蝗虫种群经济阈值模型;α_0 α_1M_1_α_2M_2_ α_3S_1 α_4S_2=C其中,M_1:狭翅雏蝗生物量;M_2:宽须蚁蝗生物量;S_1:狭翅雏蝗平均个体重量,S_2:宽须蚁蝗平均个体重量;α_0-α_4:常数.同时引入蝗虫种群数量和生物量两项参数来表达蝗虫种群的发生程度.     

羊草草原蝗虫群落的能流研究

为揭示蝗虫在草原生态系统中的地位和作用,作者在优势种蝗虫狭翅雏蝗(Chorthippusdubiua)能流研究的基础上,进一步研究了羊草草原蝗虫群落的能流动态。研究结果表明:蝗虫的次级生产力(P)为6074.32焦耳/米~2,其最大值在8月22日;呼吸量(R)为14429.06焦耳/米~2;通过蝗虫的能流(A)为20503.38焦耳/米~2,占地上第一性生产量的0.56%,其     

内蒙古草原主要蝗虫及其嗜食植物的无机化学元素特征初步研究

本文对主要蝗虫及其食料植物的无机化学成分的特征进行了讨论。所用蝗虫及有关植物均采自中国科学院内蒙古草原生态系统定位站及其邻近地区。这些蝗虫包括:短星翅蝗、宽翅曲背蝗、宽须蚁蝗、毛足棒角蝗、狭翅雏蝗、小翅雏蝗、红翅皱膝蝗、鼓翅皱膝蝗。比较并讨论了其无机化学成分的差异及含量关系的特征(表1、2)。对上述蝗虫及其食料植物间无机化学成分的差异做了图解(图1—8)。     

狭翅雏蝗的呼吸代谢及其种群的呼吸能量消耗

本文用红外CO₂气体分析仪测定了狭翅雏蝗Chorthippus dubius(2ub.)的呼吸代谢,讨论了狭翅雏蝗的呼吸代谢与温度、光暗条件及体重的关系。根据测定结果外推到野外自然种群,估出内蒙古草原三种植物群落中狭翅雏蝗种群的呼吸能量消耗。     

内蒙古草原主要蝗虫的防治经济阈值

通过取样调查确定内蒙古草原的优势蝗虫种类;根据5种优势蝗虫自然种群的结构和数量,计算了其蝗蝻和成虫的平均寿命;在半自然条件下测定了这5种蝗虫在不同发育阶段的日食量。根据这5种蝗虫蝗蝻和成虫平均寿命及其日食量数据,估算了不同蝗虫造成的牧草损失,提出了其防治经济阈值(3龄蝻,头/m²), 其中：毛足棒角蝗Dasyhippus barbipes为22.7,小蛛蝗Aeropedellus variegates minutus为37.4,亚洲小车蝗 Oedaleus asiaticus为16.9,宽须蚁蝗 Myrmeleotettix palpalis为34.3,狭翅雏蝗Chorthippus dubius为36.7。     

温、湿度对狭翅雏蝗Chorthippus dubius (Zub.)实验种群的影响

本文研究了不同温、湿度条件对狭翅雏蝗Chorthippus dubius(Zub.)实验种群的影响;在室内,温度控制在16℃、18℃、21℃、23℃、25℃、28℃、30℃、33℃、35℃和37℃,土壤含水率控制在5.0％、10.0％、14.3％,研究温度和土壤含水率对狭翅雏蝗卵孵化率的影响;温度控制在18℃、21℃、25℃、28℃、30℃、33℃、35℃和37℃,相对湿度控制在100％、80％和60％,研究温度和相对湿度对狭翅雏蝗蝻存活率、成虫生殖力和种群增长率的影响。 研究表明:温度、土壤含水率以及两者的交互作用对狭翅雏蝗卵的孵化率都有显著的影响;温度、相对湿度以及两者的交互作用对狭翅雏蝗卵的孵化率都有显著的影响。这种影响可用下列回归方程表示: y=a+b_1(T′-T)(T-T_0)+b_2(H′-H)(H-H_0)+b_3(H′/T_0-H/T)(H/T-H_0/T′)+b_4·(H′T′-HT)(HT-H_0T_0) 其中H′、H_0和T′、T_0分别为昆虫可存活的湿度的上、下限和温度的上、下限;T、H为实际温、湿度;y为存活率(或孵化率);a、b_1、b_2、b_3和b_4均为常数。 温度对狭翅雏蝗的生殖力有显著的影响,相对湿度的作用不太显著。狭翅雏蝗种群世代净增长率R_0>1的温度范围,在80％相对湿度下为27.0℃—31.5℃,在60％相对湿度下为23.0℃—29.5℃。     

围栏禁牧对羊草草原和大针茅草原蝗虫丰富度的影响

报道了围栏封育后羊草草原和大针茅草原蝗虫丰富度的变化,比较了蝗虫在羊 草草原和大针茅草原的发生特点．结果表明,以毛足棒角蝗为主导种的大针茅草原蝗虫生 物量是以小翅雏蝗为主导种的羊草草原蝗虫生物量的４～５倍;围栏封育后,羊草草原蝗 虫的生物量增加 ２４％,而大针茅蝗虫的生物量略有减少;围栏措施改变蝗虫的结构组成, 使毛足棒角蝗、鼓翅皱膝蝗、宽须蚁蝗、亚洲小车蝗等旱生和中旱生的地栖或兼栖偏地栖 种类的发生减少,条纹鸣蝗、小翅雏蝗、红腹牧草蝗等中生的植栖或兼栖偏植栖种类增加, 短星翅蝗及狭翅雏蝗的生物量在大针茅草原增加而在羊草草原减少．     

草原蝗灾的"元凶"

其实每次草原蝗灾暴发,造成严重危害,都不是一种蝗虫引起的,而是几种模样迥异,习性不同的蝗虫共同泛滥为害的结果。在内蒙古草原可引起蝗灾的蝗虫包括有毛足棒角蝗、褐色雏蝗、宽须蚁蝗、皱膝蝗、白边痂蝗、小翅雏蝗、宽翅曲背蝗、红腹牧草蝗、条纹鸣蝗、异爪蝗、狭翅雏蝗等等。本文中的所有图片都是中国科学院康乐研究员所拍摄,这是他在草原上十多年研究期间积累下来的,是研究草原蝗虫珍贵的第一手资料,本刊为首发。     

亚热带山地突脉青冈群落能量的研究

对突脉青冈（Ｃｙｃｌｏｂａｌａｎｏｐｓｉｓｅｌｅｖａｔｉｃｏｓｔａｔａ）群落植物体各组分的热值、群落能量现存量、能量年净固定量和太阳能转化效率的研究结果表明：该群落植物体各组分样品的干重热值具有一定差异,树皮热值最高,细根热值最低。突脉青同群落的能量现存量８５２０５８ｋＪｍ－２,其中地上部分７４１４１６ｋＪｍ－２,占总量的８７．０１％;地下部分１１０６４２ｋＪｍ－２,占１２．９９％。突脉青冈１９９６年群落能量净固定量为２８２７３ｋＪｍ－２,林地太阳光有效辐射能转化效率１．３５％。     

Ecological energetics of Central European grasshoppers (Orthoptera: Acrididae)

Summary Biomass and energy budgets and food utilization efficiencies of laboratory and wild populations of three Central European grasshopper species, Chorthippus parallelus (Zetterstedt), C. biguttulus (L.), and Gomphocerus rufus (L.), were studied between 1979 and 1984. Larval consumption is relatively low in C. biguttulus (C=4.3 kJ/ind.) compared with C. parallelus and G. rufus (4.9 kJ/ind.). In the adult phase (maturity) consumption rates of C. biguttulus and G. rufus (6.9 kJ/ind.) are similar, but higher in C. parallelus (7.3 kJ/ind.). The energy content decreases from the egg (23.2–24.3 J/mg dw) and body tissue (22.1–23.2 J/mg dw) to faeces (16.6–18.1 J/mg dw). The energy contents of faeces differ significantly between the species, indicating different rates of food conversion (on Dactylis glomerata). On average, the assimilation rates are about 30%, slightly lower in G. rufus. Approximate digestibility (A/C) ranges from 28.2 (G. rufus) to 35.7 (C. biguttulus) without great differences between larvae and adults. In contrast, the efficiency of conversion of ingested food (P/C) differs significantly between larval (10–11) and adult stages (3.4–3.6), and so to a much higher degree does the efficiency of conversion of digested food (P/A), from 30.3–33.5 in the larval to 9.5–14.9 in the adult period. Based on 5-year (C. parallelus) and 2-year studies (G. rufus) of the population dynamics and life tables, the energy budgets of wild populations were calculated and summarized into diagrams. Depending on the annually fluctuating densities, in both populations about 1%–2% of net primary production was consumed, and another 5%–9% was cut and dropped. The proportion of production of the grasshopper populations (body tissue) used for egg production differs in C. parallelus (28%) and G. rufus (44%). The energy cycling owing to energy storage in the living eggs amounts to 2%–3% of the total energy consumed by the population. The results are compared with the available data for grasshoppers in the literature.     

Comparative demography of an exotic herbaceous annual among plant communities in invaded canyon grassland: inferences for habitat suitability and population spread

Studies of exotic plant demography among habitats within its novel range may elucidate mechanisms of competitive dominance at local scales and invasive spread at landscape scales. We compared demographic trends of Anthriscus caucalis, an exotic herbaceous annual, across several plant communities within canyon grasslands of the Inland Pacific Northwest, USA. Greater observed survival and fecundity vital rates, as well as less spatial or temporal variability of vital rates, were considered indicators of greater plant community susceptibility to A. caucalis invasion. In addition, we investigated the role of differing habitat suitability across plant community types on potential landscape-level dispersal processes. To accomplish this objective, population matrix models were utilized to simulate stochastic transient (5 years) population growth rates (log λ_t) of A. caucalis under different net dispersal rate scenarios among the selected plant communities. We observed aboveground demography for 4 years within two bunchgrass community types and two shrub community types within a study area where livestock grazing occurred and within another study area that was not subjected to livestock grazing. Our results indicated that juvenile survival did not differ among communities, but the spatial variance of juvenile survival was significantly lower in shrub communities. Mean fecundity was significantly higher in high shrub (Celtis reticulata) communities compared to others, whereas spatial and temporal variances were significantly lower in high shrub communities compared to others. Within high shrub communities, total seed production was lower at the grazed site, which likely results from frequent livestock trampling within these refuge habitats. Under assumptions of no net seed dispersal, two of four bunchgrass sites maintained positive growth rates (log λ_t > 0; 95 % CI) whereas growth rates were positive in each shrub community. Notably, high shrub communities maintained positive growth rates under assumptions of 60 % net seed dispersal, while population growth rates in other communities declined with increasing net seed dispersal. In summary, our study suggests that high shrub communities are comparatively greater suitable habitat for A. caucalis growth and development and may act as source populations for invasive spread at a landscape scale.     

放牧干扰下的蝗虫－植物相互作用关系

本文研究了内蒙古典型草原植物和蝗虫群落在不同放牧强度影响下的多样性、均匀性和丰盛度变化。比较了蝗虫群落与植物群落在放牧梯度上的相互作用关系。研究发现,放牧干扰活动会明显地影响植物和蝗虫群落结构,但蝗虫群落结构的变化趋势并非与植物完全同步。蝗虫与植物间的联系更多地表现在植物起着蝗虫栖息地条件的作用,而并不完全是食料植物的作用。文中对放牧实践与多样性保护的关系进行了讨论。     

海莲、秋茄两种红树群落能量的研究

 本文应用热值测定,对中国两种典型红树群落,即海南岛的海莲群落及福建九龙江口的秋茄群落样品热值、群落能量现存量、能量固定量以及太阳能转化效率进行了测定和分析．结果表明：(1)红树群落各组分样品之间热值有一定的差异;一般叶、花的热值较高,而根、树皮的热值较低。(2)群落能量现存量海莲群落(1984年1月)高达178,627kcal／m2,秋茄群落为70,547kcal／m2,群落能量在不同组分以及不同高度层次上均有不同的分配比。(3)海莲群落(1983)、秋茄群落(1982)能量年净固定量分别为15,772kcal／m2和10,456kcal/m2,相应地对林地太阳光合有效辐射能的转化效率依次为3.01％和2.01％;红树群落比其他植物群落具有较高的能量固定能力及太阳能转化效率。     

Do nutrients and invertebrate herbivory interact in an artificial plant community?

The addition of nutrients has been shown to decrease the species richness of plant communities. Herbivores feed on dominant plant species and should release subdominant species from competitive exclusion at high levels of nutrient availability with a severe competitive regime. Therefore, the effects of nutrients and invertebrate herbivory on the structure and diversity of plant communities should interact. To test this hypothesis, we used artificial plant communities in microcosms with different levels of productivity (applying fertilizer) and herbivory (adding different numbers of the snail, Cepaea hortensis, and the grasshopper, Chorthippus parallelus). For analyses, we assigned species to three functional groups: grasses, legumes and (non-leguminous) herbs. With the addition of nutrients aboveground biomass increased and species richness of plants decreased. Along the nutrient gradient, species composition shifted from a legume-dominated community to a community dominated by fast-growing annuals. But only legumes showed a consistent negative response to nutrients, while species of grasses and herbs showed idiosyncratic patterns. Herbivory had only minor effects, and bottom–up control was more important than top–down control. With increasing herbivory the biomass of the dominant plant species decreased and evenness increased. We found no interaction between nutrient availability and invertebrate herbivory. Again, species within functional groups showed no consistent responses to herbivory. Overall, the use of the functional groups grasses, legumes and non-leguminous herbs was of limited value to interpret the effects of nutrients and herbivory during our experiments.     

The ecology of eelgrass, Zostera marina (L.), fish communities. II. Functional analysis

Consumption, production, and respiration of fish communities utilizing two eelgrass beds in a shallow estuarine system near Beaufort, North Carolina have been estimated for 1971–1972: annual production was 21.7 kcal/m² in each bed with pinfish accounting for 45 and 68% of the production in the Phillips Island and Bogue Sound beds, respectively. Annual community respiration was 57.9 and 69.7 kcal/m² in the two beds with pinfish accounting for 62.6 and 26.7% of the total in the Bogue Sound and Phillips Island beds, respectively. Estimation of the annual food energy consumed by the eelgrass fish community using the Winberg and daily ration methods gave values within 6% of each other.Energy turnover was high (2.8), and the efficiency of energy dissipation low for the two eelgrass fish communities, suggesting that the resident fish populations were adapted to the temperature extremes within the bed. High ecological efficiencies of 0.24 and 0.23 and the high overall efficiency of the eelgrass system (production/solar radiation) of 0.0051 and 0.0086% indicate that the eelgrass beds are efficient systems for converting consumed energy and solar radiation into fish.     

淀山湖水生维管束植物群落能量的研究

本研究测定和分析了淀山湖水生维管束植物群落样品的热值、能量现存量、能量固定量以及太阳能转化效率。结果表明：(1)水生植物的平均热值为15.39kJ·g-1DM,茎叶热值大于根部热值,挺水植物热值大于漂浮植物,后者又大于沉水植物;(2)群落热值为漂浮植物群落与挺水植物群落相近,均大于沉水植物群落;(3)群落能量现存量为挺水植物群落>沉水植物群落>漂浮植物群落。沉水植物群落能量现存量在不同水深层次上的分配有3种类型; (4)群落太阳能转化效率平均为0.54%,芦苇群落最大,可达2.90%,沉水植物群落平均为0.26%。     

高寒典型草原主要物种的株高和盖度预测种群和群落地上生物量

为快速、准确、无破坏地测定草原地上生物量,在祁连山高寒典型草原植物生长旺季,观测了冬季和春秋季放牧地60个样方内各物种的株高、盖度等生长指标。以冬季牧地紫花针茅（Stipa purpurea）、醉马草（Achnatherum inebrians）、赖草（Leymus secalinus）、扁穗冰草（Agropyron cristatum）、二裂委陵菜（Potentilla bifurca）、银灰旋花（Convolvulus ammannii）6个主要物种的株高、盖度、株高和盖度的乘积为自变量,分别预测同物种、其他物种和群落地上生物量。用春秋季牧场的数据验证模型的精确性和稳定性。结果表明：主要物种的生长指标可预测其自身、其他物种和群落地上生物量。对自身种群,株高和盖度乘积的复合因子预测效果最好;4种禾草对其他物种、二裂委陵菜对菊科植物种群,株高、盖度单因子预测效果优于复合因子;6个主要物种单独或2-6个种结合均可预测群落地上生物量,但是以6个物种株高和盖度的乘积同时预测时决定系数最大,可解释群落地上生物量89.5%的变异,为高寒典型草原群落地上生物量最优预测模型。     

Diversity and beyond: plant functional identity determines herbivore performance

1. Recent biodiversity studies have addressed various community-level effects of biodiversity change, but the number of studies on specific biotic interactions is still rather limited. An open question in the context of plant-insect-herbivore relationships is how diversity impacts the population ecology of individual species. 2. In the present study, we explored the relationship between plant species diversity and the performance and fitness of a generalist herbivore, the meadow grasshopper Chorthippus parallelus Zetterstedt (Orthoptera, Gomphocerinae). A total of 1620 fourth-instar nymphs of this insect were captured and transferred to cages (10 females and 10 males per cage) on 81 experimental grassland communities in plots containing one to 60 plant species within the Jena biodiversity experiment. 3. Median survival of grasshoppers in the experiment was 14.5 days. Survival was independent of plant species richness and number of plant functional groups in the communities, but increased if plant communities contained grasses. Plant species richness and plant functional group richness had no effect on the number of oothecae laid by females or the number of hatchlings in the next generation. 4. Functional group composition of the plant communities affected most fitness measures. Grass presence increased the number of oothecae laid by females from 0.78 +/- 0.21 to 3.7 +/- 0.41 per female, and the number of hatchlings in the next generation from 4.0 +/- 1.3 to 16.6 +/- 2.4. Certain combinations of plant functional groups increased grasshopper survival. 5. The findings indicate that the fitness of C. parallelus is influenced more by plant functional group identity than by plant species richness. In the absence of grasses, grasshoppers performed better if more than just one functional group of plants was present. We call this a 'rescue effect' of plant functional group richness.