The ICT\|2000TE meteorological measurement system was used to determine the transpiration rate of Cinnamomum camphora and the variation of main ecological factors around canopy layer.The results indicated that under f...The ICT\|2000TE meteorological measurement system was used to determine the transpiration rate of Cinnamomum camphora and the variation of main ecological factors around canopy layer.The results indicated that under full light condition in sunny days, a single peak curve was found in the daily variation of radiation and temperature around canopy layer. The radiation started to increase at 6:00 am and reached the peak of 150～800 μmol·m -2 s -1 at 12:00 , then declined to 0 at 18:00? ?0:00pm. The summer had the high variation and long time of radiation. Temperature reached the peak at 15:00—17:00. However, the daily change of humidity showed a reverse tendency in comparison with that of radiation and temperature. The humidity began to decrease at 6:00 and slumped to the lowest at 15:00 and then increased. The daily change of transpiration rate of C. camphora was found in the form of single peak curve and the highest value occurred at 14:00. The highest transpiration rate of 0.503 1 L·kg -1 DW h -1 appeared in the flourishing period of leaf, the intermediate of 0.205 4 L·kg -1 DW h -1 appeared in the senescent period, and the lowest of 0.165 1 L·kg -1 DW h -1 appeared in the defoliating period. The rank of transpiration rate under different weather condition was in the order of sunny day > changeable day > rainy day. Annually, the lowest transpiration rate of 0.043 6 L·kg -1 DW h -1 occurred in March and the zenith of 0.179 3 L·kg -1 DW h -1 appeared in June. Radiation and temperature had great influence on the transpiration rate of C. camphora.展开更多
通过外加氮源或将杉木针叶与林下植物叶混合来改变杉木林凋落物中针叶的养分状况,与杉木林针叶凋落物分解进行比较,分析针叶养分状况及其对杉木林凋落物分解速率和养分释放的影响.结果表明:将杉木针叶与林下植物叶混合和外加氮源均对凋...通过外加氮源或将杉木针叶与林下植物叶混合来改变杉木林凋落物中针叶的养分状况,与杉木林针叶凋落物分解进行比较,分析针叶养分状况及其对杉木林凋落物分解速率和养分释放的影响.结果表明:将杉木针叶与林下植物叶混合和外加氮源均对凋落物分解有不同程度的促进作用.经过153 d的分解后,未经处理的杉木针叶干质量损失率为20.49%,与林下植物叶混合的凋落物干质量损失率为43.67%,其促进作用最大;外加4 gNaNO3的促进作用次之,凋落物干质量损失率为42.07%;外加2 g NaNO3的凋落物干质量损失率为29.13%.对分解过程中各试验方案的凋落物干质量保留率进行方差分析,在开始的62 d内,与林下植被叶混合的杉木针叶凋落物分解速率和其他3种处理之间的差异显著,62 d后未经处理的杉木针叶与加2 g NaNO3的凋落物的分解速率没有显著差异,它们与加4 g NaNO3或林下植物叶的凋落物的分解速率差异显著.凋落物分解速率与凋落物初始C:N比值存在显著的线性关系.外加N源和与林下植物叶混合后,凋落物N的含量增加0.6～1.6倍,C:N比值下降0.4～0.6倍,凋落物底物质量提高,分解速率增大.分解过程中,C质量不断下降,损失24.7%～47.4%,杉木针叶中N出现富集作用,外加N源和与林下植物叶混合的凋落物N释放一定数量后保持稳定的状态.可见,外加适量N源和与林下植物叶混合能提高凋落物底物质量,促进凋落物分解和养分的释放,对维持杉木林的土壤肥力有着重要作用.展开更多
文摘The ICT\|2000TE meteorological measurement system was used to determine the transpiration rate of Cinnamomum camphora and the variation of main ecological factors around canopy layer.The results indicated that under full light condition in sunny days, a single peak curve was found in the daily variation of radiation and temperature around canopy layer. The radiation started to increase at 6:00 am and reached the peak of 150～800 μmol·m -2 s -1 at 12:00 , then declined to 0 at 18:00? ?0:00pm. The summer had the high variation and long time of radiation. Temperature reached the peak at 15:00—17:00. However, the daily change of humidity showed a reverse tendency in comparison with that of radiation and temperature. The humidity began to decrease at 6:00 and slumped to the lowest at 15:00 and then increased. The daily change of transpiration rate of C. camphora was found in the form of single peak curve and the highest value occurred at 14:00. The highest transpiration rate of 0.503 1 L·kg -1 DW h -1 appeared in the flourishing period of leaf, the intermediate of 0.205 4 L·kg -1 DW h -1 appeared in the senescent period, and the lowest of 0.165 1 L·kg -1 DW h -1 appeared in the defoliating period. The rank of transpiration rate under different weather condition was in the order of sunny day > changeable day > rainy day. Annually, the lowest transpiration rate of 0.043 6 L·kg -1 DW h -1 occurred in March and the zenith of 0.179 3 L·kg -1 DW h -1 appeared in June. Radiation and temperature had great influence on the transpiration rate of C. camphora.
文摘通过外加氮源或将杉木针叶与林下植物叶混合来改变杉木林凋落物中针叶的养分状况,与杉木林针叶凋落物分解进行比较,分析针叶养分状况及其对杉木林凋落物分解速率和养分释放的影响.结果表明:将杉木针叶与林下植物叶混合和外加氮源均对凋落物分解有不同程度的促进作用.经过153 d的分解后,未经处理的杉木针叶干质量损失率为20.49%,与林下植物叶混合的凋落物干质量损失率为43.67%,其促进作用最大;外加4 gNaNO3的促进作用次之,凋落物干质量损失率为42.07%;外加2 g NaNO3的凋落物干质量损失率为29.13%.对分解过程中各试验方案的凋落物干质量保留率进行方差分析,在开始的62 d内,与林下植被叶混合的杉木针叶凋落物分解速率和其他3种处理之间的差异显著,62 d后未经处理的杉木针叶与加2 g NaNO3的凋落物的分解速率没有显著差异,它们与加4 g NaNO3或林下植物叶的凋落物的分解速率差异显著.凋落物分解速率与凋落物初始C:N比值存在显著的线性关系.外加N源和与林下植物叶混合后,凋落物N的含量增加0.6～1.6倍,C:N比值下降0.4～0.6倍,凋落物底物质量提高,分解速率增大.分解过程中,C质量不断下降,损失24.7%～47.4%,杉木针叶中N出现富集作用,外加N源和与林下植物叶混合的凋落物N释放一定数量后保持稳定的状态.可见,外加适量N源和与林下植物叶混合能提高凋落物底物质量,促进凋落物分解和养分的释放,对维持杉木林的土壤肥力有着重要作用.
