Section 21
Chapter 20,681

Caloric values and energy allocation of a tropical seasonal rain forest and a montane evergreen broad-leaved forest in Southwest China

Lin-Hua; Cao-Min; Zhang-Jian-Hou

Zhiwu Shengtai Xuebao 31(6): 1103-1110


Accession: 020680753

Aims Energy allocation pattern is the basis for understanding energy flow processes in ecosystems. High structure complexity and species diversity of tropical forests, however, have resulted in little research on caloric values and energy allocation patterns in tropical rain forests. Tropical seasonal rain forest (TSRF) in Xishuangbanna, Southwest Yunnan is distributed on the northern edge of tropical Asia, and montane evergreen broad-leaved forest (MEBF) is located in subtropical mountain areas of middle Yunnan. Our objectives are to examine the energy allocation pattern of the two forests and test the hypothesis of Golley (1961, 1969) that caloric values of vegetation tend to increase with the altitude and latitude.Methods Caloric values were measured with a SDCM-III a oxygen bomb calorimeter. Energy allocation and sequestration were estimated based on biomass and biomass increment in a 1 hm(2) plot in each forest.Important findings The caloric value of the TSRF plot was lower than that of the MEBF plot. Caloric values decreased from tree layer to shrub layer to herb layer. Leaves showed the highest caloric values of any plant part. Due to an understory plantation of Amomum villosum, which had removed almost all saplings and seedlings, the TSRF plot stored less energy than the MEBF plot, although it still maintained a high energy sequestration rate for tropical habitats with high temperature, humidity and intensive solar radiation. The tree layer stored 97% of the energy in the TSRF plot and 88% in the MEBF plot, suggesting that tree layer plays a key role in the maintenance of energy structure in the two forests. Our results support Golley's hypothesis.

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