黃河三角洲蘆葦功能性狀對不同水分生境的適應性1)

岳喜元 岳偉 嚴寬

(山東省黃河三角洲生態環境重點實驗室(濱州學院)，濱州，256600) (江蘇師范大學)

Plant functional traits play an important role in revealing the mechanisms of plant adaptation to specific environmental conditions. We chose the dominant specie Phragmites australis in the grassland and river bank habitats of the Yellow River Delta as the research object. The characteristics of functional traits and trade-offs of P. australis was investigated, and the relationship between soil moisture content and functional traits was analyzed. The result showed that plant height, leaf length, leaf area and SLA were significantly lower in the grassland than that in river bank habitat, while leaf thickness was significantly higher in the grassland than that in river bank habitat (P<0.05). The adaptive strategies of P. australis changed due to the habitat changes, and the result reflected the conservative survival strategy of P. australis in grassland. Plant height was positively correlated with leaf length and leaf area (P<0.01), while leaf thickness was negatively correlated with plant height and leaf length (P<0.01), and positively correlated with SLA (P<0.05). Soil moisture content was positively and significantly correlated with plant height, leaf length and leaf area, while the significant and negative correlation between soil moisture content and leaf thickness was observed. The stepwise regression analysis showed that soil moisture content (10 cm

植物功能性狀是一種能夠適應生存環境變化，并對生態系統功能有一定影響的植物屬性[1-2]，是植物與環境相互作用權衡的結果。植物功能性狀作為聯系植物與環境的橋梁，其對研究植物與環境的關系具有重要作用。植物關鍵性狀(株高、葉面積等)易于測定[3]，且能將植物表型與環境因素進行聯系分析，有利于推測植物適應環境變化的生存對策[4]。

隨著對植物功能性狀的研究不斷深入，關于植物功能性狀與環境因子之間的關系已成為熱點[5]。國內外在地形[6]、溫度[7-8]與降水[9-10]等對植物功能性狀的影響方面開展了廣泛的研究，該類研究較好地反映了植物對環境的響應與適應，但目前關于植物功能性狀對生境變化適應的研究還較少[4]。不同水分生境的植物功能性狀存在明顯差異。在干旱生境中植物的比葉面積更小[11]，葉片較厚，這一現象反映了植物保守的生存策略[12]。此外，植物為了適應干旱的生存環境，采取了關閉氣孔[13]、降低比葉面積[14]這一慢速投資-收益的策略[15]，以實現對有限資源利用的最大化。植物對環境變化適應表現為部分功能性狀的改變。植物功能性狀間存在著多種關聯[16-17]，通過性狀間數量關系體現[18]。根據植物功能性狀研究植物與環境關系，有助于探究植物對環境變化的適應策略。

黃河三角洲作為我國三大河口三角洲之一，其在維持區域生物多樣性與生態系統功能中發揮著重要的作用[19]?！?br>