Nutrient cycling in age sequences of two Eucalyptus plantation species
Nutrient cycling in age sequences of two Eucalyptus plantation species
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DOI：
10.1016/j.foreco.2007.11.038
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发表时间：
2008-04
影响因子：
3.7
通讯作者：
J. Turner;M. Lambert
中科院分区：
文献类型：
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作者：
J. Turner;M. Lambert
在新南威尔士州北部海岸的两个种植园序列，巨桉（2-30年生）和桉树（2-30年生）中，对氮、磷、钾、钙和镁的积累和地上循环进行了定量研究。pilularis（3-33岁）。地上部分最大累积生物量; grandis和E. 27岁时的pilularis为394吨/公顷，33岁时为270吨/公顷，下层分别为42吨/公顷和6.7吨/公顷。估算出的乔木生物量最大现存年积累速率为：grandis和E. 5年生和7年生时的净初级生产量分别为16.4tonneha-1 year-1和15.7tonneha-1 year-1，最大净初级生产量分别为27.9和24.4tonneha-1 year-1。营养物质积累总量为E. grandis比E. pilularis在可比年龄的生长速度，较高的组织营养浓度和不同的生物量组分的分布。所有营养物质的年积累率在树冠关闭时达到峰值，然后下降，下降的速度因物种而异。两种植物氮素的年积累速率非常相似，但其他营养元素的年积累速率E. pilularis比E.奶奶。营养需要量和吸收量以E. grandis比E.而在树冠闭合时，两种植物的pilularis和pilularis的含量均达到峰值，然后下降至稳定水平。氮、磷、钾的吸收量均低于需求量，说明养分在两种植物体内的再分配，而钙、镁的吸收量则高于需求量。尽管林下植物在总生物量中占相对较小的比例，但它却是养分循环的重要组成部分。这是由于较高的周转率的生物量和较高浓度的营养物质在林下比在树木。
Accumulation and aboveground cycling of nitrogen, phosphorus, potassium, calcium and magnesium were quantified in two north coast New South Wales plantation sequences, Eucalyptus grandis (2–30 years of age) and E. pilularis (3–33 years of age). Maximum aboveground accumulated tree biomass of E. grandis and E. pilularis was 394tonneha−1at 27 years of age and 270tonneha−1at 33 years of age respectively and there was a further 42 and 6.7tonneha−1respectively contained in the understorey. The estimated maximum current annual accumulation rate of tree biomass for E. grandis and E. pilularis was 16.4tonneha−1year−1at 5 years of age and 15.7tonneha−1year−1at 7 years of age, respectively, and maximum total aboveground net primary production (NPP) was 27.9 and 24.4tonneha−1year−1, respectively. Total quantities of accumulated nutrients for E. grandis were much higher than for E. pilularis at comparable ages resulting from higher growth rates, higher tissue nutrient concentrations and different distributions of biomass components. The annual rate of nutrient accumulation for all nutrients reached a peak near the time of crown closure and then declined, the rate of decline differing between species. The annual rate of accumulation of nitrogen by the two species followed a very similar pattern but for all other nutrients was much lower for E. pilularis than for E. grandis. Nutrient requirement and uptake were higher for E. grandis than E. pilularis and however, reached a peak near crown closure in both species and then declined to a stable level in both species. Uptake of nitrogen, phosphorus and potassium was lower than requirement in both species indicating nutrient redistribution, while for calcium and magnesium, uptake was higher than requirement. Although a relatively minor component of the total biomass, the understoreys were a significant component of nutrient cycling. This was due to the higher rate of turnover of biomass and higher concentrations of nutrients in understorey than in trees.