不同方位栽植的鹅掌藤生理生态特性研究

Physiological and ecological characteristics of Schefflera arboricola——a vertical greenery plant with different directions

垂直绿化通过对空间的充分利用增加了绿化面积,对城市生态恢复与环境美化意义深远。受到太阳活动的影响,不同方位的垂直绿化所处微环境存在一定差异,其生理生态特性也会随之发生响应。以鹅掌藤(Schefflera arboricola)为研究对象,测定其在室外不同方位(建筑墙面朝向)的生长、光合和荧光生理、叶片养分含量等生理指标的差异。结果发现,北向鹅掌藤的比叶重较低,其净光合速率(10.52μmol/m^2·s)、气孔导度(0.22 mol/m^2·s)、蒸腾速率(4.31 mmol/m^2·s)、非光化学淬灭(0.72)最高;南向鹅掌藤的叶绿素SPAD值(59.33)、叶绿素荧光指标值、比叶重(140.16 g/m^2)及镁含量(3.86 g/kg)和硫含量(4.98 g/kg)含量较高,但氮含量(16.57 g/kg)、磷含量(0.95 g/kg)、钙含量(15.15 g/kg)含量较低,净光合速率相对适中;西向鹅掌藤受到气孔限制影响,其净光合速率(6.08μmol/m^2·s)最低。结果表明在垂直绿化中鹅掌藤最适宜生长在北向的墙面上,南向次之,西向较差。

Vertical greenery can increase green area by taking full advantages of the space,which has profound significance to urban ecological restoration and environmental beautification.Due to the influence of solar activity,there are certain differences in the micro-environment of vertical greening in different directions,and its physiological and ecological characteristics will also respond accordingly.In this study,the differences among growth,photosynthetic characteristics,chlorophyll fluorescence parameters,and leaf nutrient content of Schefflera arboricola in different directions were studied.The leaf mass per area of S.arboricola in north direction was relatively low,while its net photosynthetic rate(10.52μmol/m2·s),stomatal conductance(0.22 mol/m2·s),transpiration rate(4.31 mmol/m2·s)and non-photochemical quenching(0.72)were the highest.The chlorophyll SPAD value(59.33),chlorophyll fluorescence indexes,leaf mass per area(140.16 g/m2)and magnesium(3.86 g/kg)and sulphur content(4.98 g/kg)of S.arboricola in south direction were relatively high,with lower nitrogen(16.57 g/kg),phosphorus(0.95 g/kg)and calcium(15.15 g/kg)content,illustrating that its net photosynthetic rate(6.08μmol/m2·s)was relatively high.Affected by stomatal limitation,the net photosynthetic rate of S.arboricola in west direction was the lowest.The results above indicated that north direction was the most suitable direction for S.arboricola growth,south direction took second place,whereas S.arboricola growth was poor in west direction,which can provide references for rational utilization of S.arboricola in vertical greenery.