底质与水深对大叶藻和丛生大叶藻分布的影响

Effects of substrate and water depth on distribution of sea weeds Zostera marina and Z.caespitosa

考察了烟台玉岱山、担子岛和荣成褚岛海域106个采样点的大叶藻种类的分布及各采样点不同表层底质(深度3 cm以内)、根部底质(深度3～15 cm)和水深等级。对不同底质与水深条件下大叶藻Zostera marina和丛生大叶藻Z.caespitosa的出现频率进行χ2检验。结果表明:不同大叶藻的分布与表层底质、根部底质变化呈极显著相关关系(P<0.01),列联系数分别为0.612和0.640;与水深等级变化的相关性虽然显著,但列联系数仅为0.338。在表层底质、根部底质和水深等级3种因素中,两物种的分布与根部底质类型相关性最大,与表层底质类型相关性次之。研究表明,两种大叶藻在不同底质上分布的差异明显,大叶藻偏好泥与泥沙底质,而丛生大叶藻偏好沙与砾石底质。

The species composition of sea weeds Zostera marina and Z.caespitosa,surface（less than 3 cm deep） of substrate and root（3-15 cm deep） substrate,and water depths were studied at 106 sampling points in the Gulf of Yudai Hill,35 sampling points around Danzi Island in Yantai,and 31 sampling points in coast of Chudao Peninsula in Rongchen.The correlations between the divergence of two substrata and Zostera species were shown to be extremely significant（χ2 test） with the contingency coefficients of 0.612 and 0.640,and that between divergence of water depth and Zostera species were statistically significant（χ2 test） with their contingency coefficients of 0.338.The very significant factor affecting the species distribution was the divergence of root depth substrate type,followed by the surface substratum type（contingency coefficient 0.612）.The distribution of two sea weed indicated that Z.marina preferred to grow in fine sandy and silt,while pebble substrate was selected by Z.caespitosa.The divergences of two species in their rhizomes and roots are adaptative consequence to diverse substratum types.The determination of substrate type is necessary for ensuring a success in Z.marina and Z.caespitosa restoration before transplantation is carried out.