黄土高原子午岭大披针苔草能量与养分特征

Energy and nutrient characteristics of Carex lanceolata in Ziwuling of Loess Plateau

对黄土高原子午岭林区不同植被群落的优势伴生种——大披针苔草的能量和养分特征进行了研究.结果表明:随着演替的进展,处于不同演替阶段群落的大披针苔草地上部分和地下部分去灰分热值呈下降趋势.狼牙刺群落的大披针苔草地上部分去灰分热值最高,沙棘群落的最低;狼牙刺群落的大披针苔草地下部分去灰分热值最高,辽东栎群落的最低.不同群落大披针苔草地上部分热值均明显高于地下部分,且不同群落大披针苔草地下部分干质量热值和去灰分热值均呈极显著差异.处于演替早期的各群落(狼牙刺、沙棘、山杨和白桦群落)内的大披针苔草热值差异较大,而演替后期的油松和辽东栎群落的大披针苔草热值差异较小.大披针苔草地下部分干质量热值与C/N呈显著正相关关系.

The study on the energy and nutrient characteristics of Carex lanceolata, a dominant companion species in different plant communities in Ziwuling forest area of Loess Plateau showed that the ash free caloric values of the aboveground and underground parts of the species tended to decline in the communities experienced different successional stages. The aboveground part of C. lanceolata had the highest ash free caloric value in Sophora viciifolia community and the lowest in Hippophae rhamnoides community. The underground part of C. lanceolata had the highest ash free caloric value in S. viciifolia community and the lowest in Quercus liaotungensis community. The aboveground part of C. lanceolata had a remarkably higher caloric value than its underground part, and the underground part appeared to extremely significantly differ in gross and ash-free caloric values among different communities. The caloric value of C. lanceolata varied greatly in the communities going through their early successional stages （S. viciifolia, H. rhamnoides, Populus davidiana and Betula platyphylla communities）, and less greatly in the communities experiencing their later successional stages （Pinus tabulaeformis and Q. liaotungensis communities）. There was a significant positive correlation between the gross caloric value and the C/N ratio in the underground part of C. lanceolata.