华北地区几种常见园林绿化树种节水性和抗旱性评价

以压力-容积(PV)技术和切枝蒸腾法测定了华北地区6种常见绿化树种叶片的多项水分参数值(ψ_s~(sat)、ψ_w~(tlp)、RWC~(tlp)、V_a/V_p、ε~(max)、气孔关闭前后的组织相对含水率、d值、最大气孔蒸腾速率),并结合隶属函数法和聚类分析对各树种的节水性、抗旱性、保水能力、渗透调节能力进行了综合分析、比较和分类。结果表明:①针叶树为了保持光合作用的进行导致了低的保水能力,使得它们具有弱的节水性和强的抗旱性;阔叶灌木与此相反。②3种针叶树的节水性相近,圆柏抗旱性最佳,侧柏抗旱性居中,沙地柏抗旱性较差。③阔叶灌木中,大叶黄杨节水性最佳,金叶女贞和紫叶小檗的节水性相近;而大叶黄杨和紫叶小檗的抗旱性相近,均优于抗旱性最差的金叶女贞。

Evaluation of water-saving and drought resistance of landscape tree species in North China

The water parameters(ψ_s~(sat),ψ_w~(tlp),RWC~(tlp),V_a/V_p,∈~(max),the relative water component of tissue before and after stomatal closure,the value of d,and the stomatal transpiration rate of leaves of six landscape tree species of North China were studied by using pressure-volume technique and cutting sticks transpiration.The features of water-saving,drought resistance,retention water and osmosis modulation in these trees were comprehensively analysed,evaluated and classified.The results showed that:1)the capabilities of retention water of conifers to keep their capabilities of photosynthesis were low,with less desirable water-saving effect and better drought resistance,while broad-leaved shrub species were just the opposite; 2)the drought resistance of Sabina chinensis (L.)Ant was best while Sabina vulgaris's was worst,and Platycladus orientalis(L)Franco's was somewhere in between,their water-saving effects being similar; 3)in broad-leaved shrub spe- cies,the water-saving effect of Euonyrnus japonicus L.was better than Ligustrurn vicaryi and B. thunbergii var.atropurpurea chenault,both of which had the similar effect of water-saving,while drought resistances of Euonymus japonicus L.and B.thunbergii var.atropurpurea chenault were similar and better than Ligustrum vicaryi's.