Partitioning of net primary production in Eucalyptus and Acacia stands and in mixed-species plantations: Two case-studies in contrasting tropical environments
Partitioning of net primary production in Eucalyptus and Acacia stands and in mixed-species plantations: Two case-studies in contrasting tropical environments
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DOI：
10.1016/j.foreco.2012.10.034
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发表时间：
2013-08-01
影响因子：
3.7
通讯作者：
Bouillet, Jean-Pierre
中科院分区：
文献类型：
--
作者：
Epron, Daniel;Nouvellon, Yann;Bouillet, Jean-Pierre
在快速生长的树木种植园中引入固氮物种（NFS）是减少肥料投入的另一种选择。然而，混种人工林的成功取决于物种间正相互作用的平衡利用碳收支方法，结合现存生物量、地上凋落物量和土壤CO2排放量的耦合测量，研究了马占相思（Acacia mangium）替代一半桉树对地下总碳通量（TBCF）的影响，净初级生产力（NPP）及其在地上和地下生长之间的分配在两个热带地点在巴西（伊塔廷加）和刚果（Kissoko）表现出截然不同的气候，土壤条件和木材productions.Annual土壤CO2排放量（F-S）是显着较低的相思树单作比桉树单作和混合物种的立场在这两个网站。年F-S是显着较低的伊塔廷加相比，Kissoko的所有立场，而TBCF显着较低的eucalut立场。在欧洲单一栽培中，我们发现Kissoko的地上NPP（ANPP）和木材生产（木材NPP）显著低于伊塔廷加，后者几乎完全被显著较高的地下NPP（BNPP）所平衡，导致类似的NPP。同样，金合欢单作表现出显着较高的ANPP和木材NPP在伊塔廷加比在Kissoko。混合种的立场表现出显着较低的木材NPP和ANPP比桉树单一栽培在巴西的网站，而NPP的混合物没有显着不同的平均NPP的两个单一栽培。在刚果的网站，混合物的净初级生产力显着高于平均净初级生产力的两个单一的文化。混交林和桉树单作林的净初级生产力相似，但混交林的净初级生产力向地下生产力的分配显著低于桉树单作林，采伐时混交林的木材生物量比桉树单作林高1/3。混种人工林与NFS可以提倡在网站的固氮产生的生产收益不受其他资源限制。(c)2012 Elsevier B. V.保留所有权利。
The introduction of nitrogen fixing species (NFS) in fast-growing tree plantations is an alternative option to reduce fertilizer inputs. However, the success of mixed-species plantations depends on the balance between positive interactions among species (resulting from facilitation and/or complementarity) and the negative effects of interspecific competition.Using a carbon budget approach and coupling measurements of standing biomass, aboveground litterfall and soil CO2 efflux, we assessed the influence of replacing half of eucalypt trees by Acacia mangium on total belowground carbon flux (TBCF), net primary production (NPP) and its partitioning between above- and belowground growth at two tropical sites in Brazil (Itatinga) and in Congo (Kissoko) exhibiting contrasting climates, edaphic conditions and wood productions.Annual soil CO2 efflux (F-S) was significantly lower in the acacia monocultures than in eucalypt monocultures and mixed-species stands at both sites. Annual F-S was significantly lower at Itatinga compared to Kissoko for all stands while TBCF was significantly lower in the eucalypt stands only. In the eucalypt monocultures we found a significantly lower aboveground NPP (ANPP) and wood production (wood NPP) at Kissoko compared to Itatinga that was almost fully balanced by a significantly higher belowground NPP (BNPP), leading to similar NPP. Similarly, acacia monocultures exhibited significantly higher ANPP and wood NPP at Itatinga than at Kissoko. The mixed-species stands exhibited a significantly lower wood NPP and ANPP than the eucalypt monocultures at the Brazilian site while NPP of the mixture was not significantly different than the average NPP of the two monocultures. At the Congolese site, NPP of the mixture was significantly higher than the average NPP of the two monocultures. NPP was similar in the mixed-species stand and the eucalypt monoculture with a significantly lower partitioning of NPP to belowground production, leading to a one third higher wood biomass at harvest in the mixed-species stand.A positive effect of growing eucalypts with the nitrogen fixing acacia trees on stand wood production occurred at Kissoko but not at Itatinga. Mixed-species plantations with NFS can be advocated at sites where the productive gains resulting from nitrogen fixation are not compromised by other resource limitations. (c) 2012 Elsevier B.V. All rights reserved.