摘要
【目的】量化共存树种的碳、氮、磷含量及其计量关系的器官间和种间差异,探讨共存树种养分元素的器官间分配策略和种间利用差异,以期增强对整树水平的碳、氮、磷储量和分配格局的认识。【方法】选取黑龙江省帽儿山天然次生林中的10个共存阔叶树种,研究叶、枝、皮、边材、心材、树桩、大根(5 mm<直径≤30 mm)、粗根(2 mm<直径≤5 mm)和细根(直径≤2 mm)9个器官的碳含量(C)、氮含量(N)、磷含量(P)以及碳氮比(C:N)、碳磷比(C:P)和氮磷比(N:P),用变异系数表达器官和树种间的差异,用标准主轴回归斜率检验元素两两之间的异速或等速增长关系。【结果】树种、器官及其交互作用对C、N、P及C:N、C:P、N:P影响显著(树种对C:P影响不显著除外);从均值来看,资源获取器官(叶和细根)的C、N、P及N:P显著高于其他器官,木质部(边材、心材)的C:N、C:P显著高于其他器官;从种间变异来看,叶元素含量及其计量比的种间差异均较低;细根N、C:N和N:P的种间差异均较高,而P和C:P的种间差异均较低,表明该地区树木将有限的氮元素优先分配给光合器官;大部分器官的元素间相关关系不显著,表明单一器官的养分计量关系不能直接反应其他器官或整树水平的计量关系;器官间C和N、C和P相关关系因树种而异,但N和P关系各树种高度一致。【结论】树木器官间的C、N、P、C:N、C:P和N:P的差异与器官功能分异紧密相关。总体上温带森林树种将受限的氮元素优先分配到叶,同时氮也会限制木材固碳。各器官对碳、氮、磷元素的利用在群落共存种间存在明显差异,可能有助于降低种间竞争。无论是种内还是种间,一个器官的养分含量及其计量关系均不能直接反应其他器官的情况,因此仅用某一器官来量化整树水平的碳、氮、磷储量及其分配格局是不准确的,今后相关研究应充分考虑元素含量的器官间和种间差异。
【Objective】In order to enhance understanding of the storage and allocation of carbon(C),nitrogen(N)and phosphorus(P)at the whole tree level,we quantified these inter-organ and inter-specific differences in C,N,and P contents and their stoichiometric relationship in the co-existing tree species,and explored the strategies of inter-organ nutrient allocation of coexisting tree species and inter-specific difference in nutrient uptake.【Method】The C,N,P contents and their stoichiometry for different organs(leaf,branch,bark,sapwood,heartwood,stump,5 mm<diameter≤30 mm large root,2 mm<diameter≤5 mm coarse root,and diameter≤2 mm fine root)were measured for 10 broadleaf tree species in a temperate mixed deciduous forest in Maoershan area,Heilongjiang Province.The coefficient of variation(CV)was used to express the differences among organs or tree species,and the slopes of standardized major axis regressions were used to test the allometric or isometric scaling relationships between elements.【Result】The effects of tree species,organs and their interaction on C,N,P contents,C:N,C:P and N:P were all significant except the effect of tree species on C:P.For mean values,resource acquisition organs(leaf and fine root)had higher C,N,P contents and N:P,while the xylem(sapwood and heartwood)showed higher C:N,C:P than the other organs.For inter-specific variations,leaves had low inter-specific CVs of element contents and their stoichiometric ratios;fine roots had high inter-specific CVs of N,C:N,and N:P,but low inter-specific CVs for Pand C:P,suggesting that tree species in this area preferentially allocated the limited element N to the photosynthetic organ.For most organs,relationships between elements were not significant,indicating that the nutrient stoichiometric relationships for single organ could not directly represent the nutrient stoichiometries for other organs or at the whole tree level.The relationships between C and N or C and P across the nine organs varied with species,but the relationship between N and P was highly consistent in different species.【Conclusion】The differences in C,N,P contents and their stoichiometric ratios were closely related to the functional differentiation among organs.Overall,the limited element N was preferentially allocated to leaves and constrained carbon sequestration in wood;whereas the utilization of C,N,and P for each organ diverged obviously among the coexisting species,which was likely to help reduce the inter-specific competition.No matter at the intra-specific or the inter-specific levels,the nutrients contents and their stoichiometric relationships of single organ could not directly reflect that of other organs.Therefore,only using one organ to assess the C,N,and P storage and allocation patterns at the whole tree level was inaccurate,thus future studies should fully consider the inter-organ and inter-specific differences of element contents.
作者
赵瑞
王传宽
全先奎
王兴昌
Zhao Rui;Wang Chuankuan;Quan Xiankui;Wang Xingchang(Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education,Northeast Forestry University Center for Ecological Research,Northeast Forestry University,Harbin 150040)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2021年第2期1-11,共11页
Scientia Silvae Sinicae
基金
国家科技支撑计划项目(2011BAD37B01)
教育部长江学者和创新团队发展计划项目(IRT_15R09)。
关键词
生态化学计量学
器官间差异
种间差异
局域尺度
ecological stoichiometry
inter-organ variation
inter-specific variation
local scale
