摘要
以生长在陕西黄土高原半干旱气候区安塞县和半湿润气候区长武县的刺槐人工林为研究对象,采用土钻法获取根样,研究不同气候区刺槐细根的垂直分布特征。结果表明:两地刺槐细根分布差异较大,安塞县刺槐细根平均分布深度为250cm,长武为200cm;安塞阴、阳坡立地上刺槐细根表面积特征值分别是长武的5.06和8.29倍。无论是在阴坡还是阳坡立地上,安塞刺槐细根表面积特征值均在土壤表层0～20cm处达到最大值,且随土层加深逐渐减小;长武刺槐细根表面积特征值峰值出现在较深的土层,阴、阳坡均在60cm左右。安塞刺槐细根约80%分布于0～150cm土层中,长武集中在0～100cm土层。此外,两地刺槐细根表面积特征值阴坡大于阳坡。水分条件不同是造成这种差异的主要原因。模型S=AhB(C+Dh+Eh2+Fh3)可以较好地拟合两地刺槐细根的垂直分布特征,安塞县不同立地的拟合决定系数R2均在0.94以上,长武县在0.80以上。
Robinia pseudoacacia is one of the major planting tree species in the Shaanxi Loess Plateau. Changwu county and Ansai County lie in the semihumid and semiarid region of the area, respectively. In this paper, the fine root vertical distributions of R. pseudoacacia growing at the two counties were studied, using soil auger method. The results showed that the fine root vertical distribution had distinct differences in these two regions. The mean depth of fine root vertical distribution was 250 cm in Ansai County, and only 200 cm in Changwu County. The average fine root surface area （cm^2· dm^- 3 ） on shady and sunny slope of Ansai County was 5.06 and 8.29 times over the value of Changwu County, respectively. Both on shady and sunny slope of the two counties, the maximum value of fine root surface area presented soil surface （0 - 20 cm） and then decrease slowly in Ansai County. However, the maximum value appeared on 60 cm in Changwu County. About 80 percent fine root of R. pseudoacacia distributed in 0 - 150 cm soil layer in Ansai County, and in 0 - 100 cm in Changwu County. In addition, the fine root was richer on shady slope than sunny slope both in Ansai and Changwu County. The fine root vertical distribution characteristics was significantly related to soil water, which was a key factor to influence fine root distribution. The model S = Ah^B（C ＋ Dh ＋ Eh^2 ＋ Fh^3 ） can well described R. pseudoacacia＇s fine root vertical distribution in these two regions, the fit decide coefficient （ R2 ） more than 0.94 in Ansai and more than 0.80 in Changwu County. The research of R. pseudoacacia＇s fine root vertical distribution under different soil water environment will help to further explore the relationship between fine root system and soil water and the reason of soil drification in the Leoss Plateau.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2006年第11期1-7,共7页
Scientia Silvae Sinicae
基金
国家自然科学基金(30671673)
教育部博士点基金(20030712002)
黄土高原土壤侵蚀与旱地农业国家重点实验室基金(10501-123)
关键词
黄土高原
刺槐
细根表面积
细根垂直分布
模型
Leoss Plateau
Robinia pseudoacacia
fine root surface area
fine root vertical distribution
model
