黄土丘陵沟壑区中间锦鸡儿的生长特征

Growth Characteristics of Caragana Intermediain the Loess Hilly-gully Region

在黄土丘陵沟壑区选取4种典型的梁峁沟坡生境(即丘顶、阳坡、阴坡、沟底),研究土壤水分特征和中间锦鸡儿的生长特征.结果表明:4个生境土壤含水量分别为阴坡11.2%,沟底7.31%,丘顶7.14%,阳坡4.66%,显著性分析表明,阴坡含水量显著高于其它生境,阳坡显著低于其它生境,丘顶和沟底含水量差异不显著;土壤水分可利用性由难到易依次为阴坡>阳坡>丘顶>沟底.中间锦鸡儿的地上生物量和总生物量均表现为阳坡最大、丘顶和阴坡次之、沟底最小;不同生境中间锦鸡儿生物量资源分配差异显著,表现为阳坡叶生物量分配最大,沟底茎生物量分配最大,丘顶根生物量分配最大;中间锦鸡儿的根系可塑性强,阳坡根系入土最深,丘顶根系水平分布最广,阴坡根系的垂直和水平生长能力均较强.生长特征分析结果表明:中间锦鸡儿在阳坡的生长优于其它生境,由于根系发达能在以砒砂岩为基质的阴坡生长良好.

Caragana intermedia is one of the common species widely distributed in the loess hilly-gully loess region. Soil characteristics and growth characteristics of Caragana intermedia in the typical habitats of hilltop, shade, sunny and gully bottom were studied. The results are as fol- lows：the soil water content was significantly highest in shade （11.2 %）, with no significant differ- ence between gully bottom （7. 31%） and hilltop （7. 14%）, and significantly smallest in sunny （4.66%）. However,the water availability to plants from hard to easy were shady,sunny,hilltop and gully bottom in order. The aboveground biomass and total biomass of Caragana intermedia from high to low in different habitat types were sunny,hilltop, shade and gully bottom in order. Biomass allocations were significantly different among the four habitats, leaf biomass allocation was largest in sunny. Stem biomass allocation was largest in gully bottom and root biomass allocations was lar- gest in hilltop. The root morphological plasticity was high, the main root length was largest in sunny and the lateral root length was largest in hilltop. The results also showed that the growth of Cara- gana intermedia in sunny was superior to others. It can survive well with a developed root system in shade covered by exposed Pisha stone.