华南典型人工林的土壤物理性质及其水源涵养功能

对杉木、马尾松、湿地松、尾叶桉和马占相思林的土壤物理性质、凋落物持水量以及土壤贮水性能进行了研究。5种林分土壤的毛管孔隙度、非毛管孔隙度和总孔隙度均为上层大于下层,而土壤容重为上层小于下层。总体来看,5种林分中杉木和马占相思林土壤疏松、孔隙度大;尾叶桉林土壤紧实、孔隙度小,马尾松林和湿地松的土壤孔隙度中等。凋落物最大持水量呈现杉木林(18thm-2)>马占相思林(15thm-2)>尾叶桉林(14thm-2)>马尾松林(11thm-2)>湿地松林(10thm-2)。土壤是森林涵养水源的主体,其最大持水量占林地最大持水量的99%以上,顺序为杉木林地和马占相思林(2064和2061thm-2)>湿地松林(2041thm-2)>马尾松林(2032thm-2)>尾叶桉林(1941thm-2)。林地最大持水量的顺序为杉木林地(2082thm-2)>马占相思林地(2076thm-2)>湿地松林地(2051thm-2)>马尾松林地(2043thm-2)>尾叶桉林地(1955thm-2)。

Soil Physical Properties and Water Conservation Function of Model Plantations in South China

Soil physical properties and water holding capacities of litter and woodlands were studied under Cunninghamia lanceolata, Pinus massoniana, Pinus elliottii, Eucalyptus urophylla and Acacia mangium plantations in South China. The capillary porosities, non-capillary porosities and total porosities of upper soil layer in the five plantations were greater than those of lower soil layer, whereas the soil densities were lower than the latter. Generally, the soils under C. lanceolata and A. mangium woodlands were porous, whereas the soil under E. urophylla woodland was solid, and the P. massoniana and P. elliottii showed a median soil density. The order of total water holding capacity of litter was C. lanceolata plantation (18t hm-2) > A. mangium plantation (15t hm-2)>E. urophylla plantation (14t hm-2) > P. massoniana plantation (11t hm-2) > P. elliottii plantation (10t hm-2). Soil water holding amount accounted above 99% of that of the woodlands,with the order of C. lanceolata plantation and A. mangium plantation (2064 and 2061t hm-2) > P. elliottii plantation (2041t hm-2) > P. massoniana plantation (2032t hm-2) > E. urophylla plantation (1941t hm-2). The order of water holding amount of the woodlands was C. lanceolata woodland (2082t hm-2)>A. mangium woodland (2076t hm-2)>P. elliottii woodland (2051t hm-2)>P. massoniana woodland (2043t hm-2)>E. urophylla woodland (1955t hm-2).