初级生产
多年生植物
矿化(土壤科学)
氮气
氮气循环
生物量(生态学)
温带气候
植物凋落物
温带森林
垃圾箱
农学
动物科学
生物
化学
植物
生态学
生态系统
有机化学
作者
Knute J. Nadelhoffer,John D. Aber,Jerry M. Melillo
出处
期刊:Ecology
[Wiley]
日期:1985-08-01
卷期号:66 (4): 1377-1390
被引量:501
摘要
The relationships between above— and belowground net primary production and soil nitrogen availability were studied at nine temperate forest sites. Annual allocations of nitrogen (N) and net primary production to leaf litter, perennial tissues (wood + bark), and aboveground biomass all increases significantly (P < .01) in relation to apparent N uptake by vegetation (N " u) as calculated using field measurers of net N mineralization (N m ) and other major N fluxes to and from available N pools. Mean annual N content and biomass of fine roots @<3.0 mm diameter) were both negatively correlated with N u (° = —0.71, P < .05; ° —0.63, ° < .10, respectively). However, only °50% of N m at each site could be accounted for by allocation to aboveground litter and perennial tissues. Assuming that mineralized N not accounted for by allocation to these components was taken up by vegetation and allocated to fine roots, annual N allocation to fine roots (N f r ) was a constant fraction of N uptake. Therefore, N f r increased in absolute terms with both N m and apparent N uptake. Fine—root N turnover rates (or N f r /fine—root N content) also increased as N m and N u increased. Provided that fine—root biomass and N turnover rates were similar within sites, allocation of production to belowground biomass also increased relative to increases in soil N availability. Furthermore, the proportion of total net production allocated to belowground biomass did not decrease with increased N availability.
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