科尔沁沙地小叶杨和杂交杨一些生理生态特性的比较研究

Comparative studies on several physiological and ecological characteristics of Populus simonii and Populus spp. in kerqin sandyland

采用AP4气孔计和PV曲线研究了小叶杨和杂交杨气孔导度和水分状况在不同季节的变化特征 ,结果表明 :①在干旱的 5、6月份 ,小叶杨的气孔导度 (5月 :32 0 .6mmol·m-2 ·s-1 ,6月 :2 83 .0mmol·m-2 ·s-1 )远远高于杂交杨 (5月 :46 5mmol·m-2 ·s-1 ,6月 :12 6mmol·m-2 ·s-1 ) ;在湿润的 7月又低于杂交杨 (小叶杨 456 7mmol·m-2 ·s-1 ,杂交杨 60 4 5mmol·m-2 ·s-1 ) ;在生长近结束的 8月底二者气孔导度近等 (小叶杨 42 1 6mmol·m-2 ·s-1 ,杂交杨 32 8 8mmol·m-2 ·s-1 ) ;②小叶杨和杂交杨嫩叶在干旱的 5月渗透调节能力、抗旱能力相差不多 ,以后各月杂交杨则高于小叶杨 ,6月最明显 ;随着植物枝条木质化程度的提高 ,二者渗透调节能力和抗旱性均呈上升趋势。

The changing characteristics of stomatal conductance and water status of two poplars in different seasons were studied by AP4 parometer and Pressure Volume techniques. The results showed that: (1) the stomatal conductance of P.simonii was much higher than P. spp.in dry May and June, they were 320.6 mmol·m -2 ·s -1 ,283.0mmol·m -2 ·s -1 and 46.5mmol·m -2 ·s -1 ,12.6mmol·m -2 ·s -1 ,respectively. The state of affairs reversed in humid July, the data were 456.7 mmol·m -2 ·s -1 of P. simonii and 604.5mmol·m -2 ·s -1 of P.spp.; In the end of growing season (the end of August), the stamatal conductance was almost the same of two poplars. (2) the osmoregulational abilities and drought resistance of tender leaves weres no different of two trees in dry May, then the abilities of P. spp. was a little higher than P. simonii and there was a significant different in June. The osmoregulational abilities and drought resistance of two poplars were tending to increase with leaves and twigs getting older.