内蒙古羊草+大针茅草原植被生产力的研究Ⅰ、群落总生产量的分析

本项研究从1981年—1986年在内蒙古锡林河流域用规则定位样方测定法对羊草+大针茅草原群落在全年生长季分期进行各植物种群密度、高度、物候期的登记、测定鲜重生物量,并在实验室烘干,再测定干重生物量。六年所取得的数据通过计算机与综合分析得到以下结果。 六年来群落地上现存生物量的季节变化形式都是单峰曲线,每年的高峰值出现在8月中旬到9月初旬。虽然每年峰值不同但曲线表现了一致的趋势。说明群落生物量的季节动态有一定规律性。六年内的最高测值是332.51g/M~2(1981年9月1日测得)。经分析,各年份的群落地上现存生物量相对增长速度的变化趋势是从生长季开始到末尾逐渐降低,最后达到负值。高峰值出现在正负值之间的时间内。根据数据建立了群落地上现存生物量动态的拟合曲线数学模型。从而可每年植物萌动到出现最大的现存生物量其公式为:W=e_(-ea-k)t。从推算任一时间的地上现存生物量为: B_t=B-(?)-ea-kt 群落的抽象平均高度为各种群的平均高度以相应的相对密度为概率值的累加,抽象平均高度的变化与生物量的变化相符合。群落抽象平均密度为各种群的平均密度以相应的相对生物量为概率的累加。群落的平均个体生物量为群落的平均现存生物量与群落的抽象平均密度的比值。这些研究均有一定的生态学意义。

A Research on the Primary Production for Anenrolepidlnm chinense+Stipa glandis Steppe in Inner Mongolia

In this paper, a systematic research is made into the dynamic laws ofthe primary production in the Aneurolepidium Chinense + stipa grandis steppe. During six years from 1981 to 1986, in the whole plant growth seasonspan for every year from the time when plant innovation bud began to ger-minate and the green leaf appeared until the time when the plant stem andleaf turned yellow and died, we carried out field sampling. The sampling me-thod was to survey the given plot system and regularly, and, according togiven size area, record the density, height and phenological stage of everyplant population, stove it dry and survey its weight indoors. With the computer, we made a comprehensive analysis of the data deri-ved in these six years, and got the main conclusions as follows: 1. For six years, the behavior patterns of the community above-groundstanding biomass were all one-peak curves. The peak values came generallyin the time-span of Mid-August to Mid-September. we have compared thecommunity above-ground standing biomass of one year with that of anotheryear and found that there was high-production year, ordinary-production yearand low-production year. But, the season-dynamic laws of the communityaboue-ground standing biomas within every year was relatively of stability.During these six years, the greatest value estimated of the community abo-ve-ground standing biomass was 332.51g/m~2, which occurred during thelast ten days of August in 1981. The imitating curve mathematrical model for the community primary pro-duction was founded. The curve forms for these years were basically uni-form, but their parameter values were not the same. Yet we got the averageaccumulated-weight parameter curve for the six years. 2. Changes of abstract mean height and abstract mean density of the com- munity were studied. The relationship between these changes and the com-munity production also was studied. The community abstract mean height isthe accumulative total of each and every population mean height with its cor-responding relative density as a probability weight. The community abstractmean density is the accumulative total of each and every population meandensity with its corresponding relative biomas as a probability weight. We researched about changing patterns of the community mean individualbiomass. The community mean individual biomass is a ratio value of the com-munity mean standing biomass to the community abstract mean density.These researches are of certain ecological theory significance. 3. We likewise researched into the relationship between the communityabove ground biomass and the below-ground biomass, between dry-weightbicmass and green-weight bicmass and the relationship between the commu-nity production and soil moisture.