准噶尔盆地梭梭群落地上生物量及季节变化研究——以克拉玛依农业综合开发区为例

NPP and seasonal variation of Haloxylon community in Junggar Basin of Xinjiang——A case study at Karamay agricultural development region

根据样地调查资料,对位于准噶尔盆地的克拉玛依农业开发区外围荒漠植被的生物量及季节变化进行了研究。通过对梭梭自然群落地上生物量的研究表明,梭梭群落在一年的生长周期内没有明显的生长变化,只有两个生长高峰分别在6月下旬和8月下旬出现,但是绿色同化速率快。梭梭地上生物量中,多年生枝条比例最多占地上生物量的60%,当年生绿色同化枝生物量较少,一般占30%以下。5月份梭梭当年生绿色同化枝生长比较缓慢,地上生物量42 052．197g/m^2；7～8月份达到高峰76 457．18～92 922．598g/m^2,这是梭梭当年生绿色同化枝生长最旺盛、最有活力的时期；进入9月份随光合作用的下降生物量也下降至86 794．669g/m^2；10月份生物量迅速下降11月接近零,准备冬眠,脱落大部分枝条被并入非同化系统。梭梭群落地上生物量增长规律符合Logistic增长模型；其地上现存量季节动态呈二次抛物线方程y=a+bx+cx^2形式；梭梭绿色同化系统(AS)和非同化系统(UAS)的现存量集中分布于地面8～60cm和20～90cm的范围内,属典型的中繁型群落。梭梭群落的生物量及其季节变化与梭梭当年生绿色同化枝的萌发、生长、脱落有密切的关系。

Based on the investigation data of the desert vegetation plots in the peripheral regions of the artificial oases--the Karamay agricultural development region in Junggar Basin, Xinjiang, the biomass and seasonal dynamics of haloxylon community were studied in this paper. By analyzing the species composition, horizontal structure, aspect and aboveground biomass of haloxylon community, it indicated that the maximum biornass values appeared in the late June and the late August respectively in this area. The aboveground biomass of perennial shoots makes up 60% of the aboveground biornass,and the newly shoots usually makes up 30% or less of the total aboveground biomass. The growth of the newly shoots of haloxylon on May is rather slow with the biomass of 42 052. 197 g/m^2, the growth of the newly shoots reaches an peak period from July to August with the biornass of 76 457.18 - 92 922. 598 g/m^2, the growth the newly shoots descends to 86 794. 669 g/m^2 on September and promptly drops to zero from October to November. The aboveground biomass growth of haloxylon community accorded with the Logistic increasing model, the seasonal dynamics of present aboveground biomass appeared as the quadratic equation Y = a ＋ bx ＋ cx^2. There were abundant ephemeral and annual plants in the haloxylon community, in which vegetation species of the constructive synusia was very simple. The influence of the biomass related closely to the germination, growth and abscission of Haloxylon assimilating shoots, rapid growth and death of ephemeral and annual plants.