寒温带兴安落叶松林生态系统养分特征

森林生态系统营养元素的积累和循环是维护森林生态系统健康稳定的关键因素之一,对森林生态系统的存在和发育具有重要的意义。文章对寒温带兴安落叶松林生态系统的养分输入、贮藏和输出特征进行了初步的研究。结果表明:林冠对Ca、Mg、Fe总体呈现吸附趋势,其中对Ca元素的吸收最为显著;P、K元素则是经林冠后含量增加;微量元素Mn的输入主要来自降雨,林冠对其的利用很少;各元素在植物和土壤中贮存的比例存在较大的差异,其中Ca、Mg、Mn主要贮存于植物体中,其贮存量约占86.06%、84.25%和94.18%;植物体中P、K的贮存量约占总贮量的44.62%和58.82%;Fe主要贮存于土壤当中,植物体中Fe的贮存量仅占总贮存量的9.16%;在兴安落叶松林生态系统中径流输出是养分元素主要的输出途径,其中P、K、Mn元素的年输入量大于输出量,生态系统中养分含量呈累积增加趋势,而Ca、Mg、Fe元素的输出量大于输入量,表现为养分流失,其中Ca的损失量最大。

Nutrient characteristics of Larix gmelinii forest ecosystem in cold temperate zone

The nutrition accumulation and cycle in ecosystem is a key point in maintaining forest ecosystem health and stabilization and is important for ecosystem existence and development. In this article,the primary study was conducted about characteristics of nu-trition input,storage and output in Larix gmelinii forest ecosystem in cold temperate zone. The result indicated that：canopy could ab-sorb Ca,Mg,Fe and the absorption of Ca was the most significant among three kinds of mineral elements;The contents of P and K in-creased after passing through canopy. The input of trace mineral Mg mainly came from rainfall and trace mineral Mg was rarely used by canopy. There was a big difference among the proportions of various elements stored in plants and in soil. Ca,Mg and Mn were mainly stored in vegetation and the proportions were 86.06%,84.25%and 94.18%,respectively. 44.62%of total P and 58.82%of to-tal K were stored in vegetation. Fe was mainly stored in soil,and Fe stored in plant is only 9.16%of total storage amount. In Larix gmelinii forest ecosystem,runoff output was the main output way of nutrient elements. The annual input of P,K and Mn was higher than the annual output. The contents of P,K and Mn in ecosystem increased in an accumulated manner. However,the annual output of Ca,Mg and Fe was higher than the annual input,which means nutrient loss,and the loss of Ca is most serious.