Three-dimensional Morphometric Analyses of Hominoid Lower Molars from Yuanmou in Yunnan Province,China

1　ＩｎｔｒｏｄｕｃｔｉｏｎＡｍｏｎｇｔｈｅｆｏｕｒＭｉｏｃｅｎｅｈｏｍｉｎｏｉｄｓｉｔｅｓｏｆＫａｉｙｕａｎ ,Ｌｕｆｅｎｇ ,ＹｕａｎｍｏｕａｎｄＢａｏｓｈａｎｉｎＹｕｎｎａｎＰｒｏｖｉｎｃｅｏｆＣｈｉｎａ ,ＬｕｆｅｎｇａｎｄＹｕａｎｍｏｕａｒｅｔｈｅｒｉｃｈｅｓｔｆｏｓｓｉｌｓｉｔｅｓ .Ｓｉｎｃｅｉｔｓｆｉｒｓｔｄｉｓｃｏｖｅｒｙｉｎ 1 975,ｍａｎｙｃｏｌｌｅａｇｕｅｓａｒｏｕｎｄｔｈｅｗｏｒｌｄｈａｖｅｂｅｅｎｉｎｖｏｌｖｅｄｉｎｔｈｅｓｔｕｄｙｏｆＬｕｆｅｎｇｐｉｔｈｅｃｕｓｆｏｓｓｉｌｓ .Ｈｏｗｅｖｅｒ,ｎｏａｇｒｅｅｍｅｎｔｈａｓｂｅｅｎｒｅａｃｈｅｄｏｎｔｈｅｒｅｌａｔｉｏｎｓｈｉｐｏｆＬｕｆｅｎｇｐｉｔｈｅｃｕｓｔｏｏｔｈｅｒＭｉｏｃｅｎｅｈｏｍｉｎｏｉｄｓｆｏｕｎｄａｒｏｕｎｄｔｈｅｗｏｒｌｄｏｒｏｎｉｔｓｐｈｙｌｏｇｅｎｙ .ＷｕＲｕｋａｎｇｂｅｌｉｅｖｅｓｔｈａｔｔｈｅｒｅａｒｅａｓｅｒｉｅｓｏｆｍｏｒｐｈｏｌｏｇｉｃａｌｄｉｆ ｆｅｒｅｎｃｅｓｂｅｔｗｅｅｎＬｕｆｅｎｇｐｉｔｈｅｃｕｓａｎｄｔｈｅＳｉｖａｐｉｔｈｅｃｕｓｓｐｅｃｉｍｅｎｓｆｏｕｎｄｉｎＴｕｒｋｅｙａｎｄＰ...     

陆生脊椎动物生态学研究的过去,现在和将来

陆生脊椎动物生态学研究的过去、现在和将来（前苏联科学院动物进化形态学与生态学研究所,莫斯科）Ｐａｓｔ,ＰｒｅｓｅｎｔａｎｄＦｕｔｕｒｅｏｆＥｃｏｌｏｇｉｃａｌＲｅｓｅａｒｃｈｏｎＴｅｒｒｃｓｔｒｉａｌＶｃｔｅｂｒａｔｃｓ￥．（ＩｎｓｔｉｔｕｔｅｏｆＡｎｉｍａｌＥｖｏｌｕｔｉｏｎａｒｙＭｏｒｐｈｏｌｏｇｙａｎｄＥｃｏｌｏｇｙ,ｔｈｅＦｏｒｍｅｒＡｃａｄｅｍｙｏｆＳｃｌｅｎｃｅｓｏｆＳｏｖｉｅｔＵｎｉｏｎ）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（４）：６６－７１。Ｔｈｉｓｐａｐｅｒｄｅｓｃｒｉｂｅｓｔｈｅｍａｉｎｓｔａｇｅｓ,ｄｉｒｅｃｔｉｏｎｓａｎｄｉｔｅｍｓｏｆｅｃｏｌｏｇｉｃａｌｒｅｓｅａｒｃｈｉｎｔｈｅｆｏｒｍｅｒｓｏｖｉｅｔＵ－ｎｉｏｎ．ＥｃｏｌｏｇｉｃａｌｒｅｓｅａｒｃｈｉｎｔｈｅｃｏｕｎｔｒｙｗａｓｒｅｓｔｒｏｄｅｄｂｙｍａｎｙｓｕＵｅｃｔｉｖｅａｎｄｏＵｅｃｔｉｖｅｆａｃｔｏｒｓａｎｄｓｔｉｌｌｌａｇｓｂｅｈｉｎｄｔｈｅｗｏｒｌｄｌｅｖｅｌｉｎｍａｎｙａｓｐｅｃｔｓｓｕｃｈａｓｐｏｐｕｌａｔｉｏｎｄｙｎａｍｉｃｓｔｈｅｏｒｙ,ｃｏｍｍｕｎｉｔｙｒｅｓｅａｒｃｈ,ｅｃｏ－     

生态学的精神价值

生态学的精神价值陈清硕（江苏农学院扬州２２５００１）ＳｐｉｒｉｔｕａｌＶａｌｕｅｏｆＥｃｏｌｏｇｙ￥．ＣｈｅｎＱｉｎｇｓｈｕｏ（ＪｉａｎｇｓｕＡｇｒｉｃｕｌｔｕｒａｌＣｏｌｌｅｇｅ,Ｙａｎｇｚｈｏｕ２２５００１）：ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（３）：６８－７２．Ｔｈｉｓｐａｐｅｒｄｅｓｃｒｉｂｅｓｔｈｅｆｕｎｃｔｉｏｎｓｏｆｅｃｏｌｏｇｙｉｎｔｈｅｐｒｏｇｒｅｓｓｏｆｓｏｃｉａｌｉｄｅｏｌｏｇｙａｎｄｃｉｖｉｌｉｚａｔｉｏｎ．Ｅｃｏｌｏｇｙｈｅｌｐｓｂｒｉｎｇｉｎｔｏｂｅｉｎｇｔｈｅｃｏｎｓｔｒｕｃｔｉｏｎｏｆａｓｃｉｅｎｔｉｆｉｃｗｏｒｌｄｏｕｔｌｏｏｋａｎｄｉｎｃｒｅａｓｅｔｈｅｅｃｏｌｏｇｉｃａｌｃｏｎｓｃｉｏｕｓ－ｎｅｓｓｏｆｍａｎｋｉｎｄ．Ｉｔａｌｓｏｓｕｐｐｌｉｅｓａｔｏｔａｌｄｅｖｅｌｏｐｍｅｎｔａｌｐｏｉｎｔｏｆｖｉｅｗｆｏｒｔｈｅｓｏｃｉｅｔｙａｎｄｐｒｏｖｉｄｅｓａｇｒｅａｔａｅｓｔｈｅｔｉｃｖａｌｕｅ．Ｔｈｅｓｐｉｒｉｔｕａｌｖａｌｕｅｏｆｅｃｏｌｏｇｙｓｈｏｕｌｄｎｅｖｅｒｂｅｎｅｇｌｅｃｔｅｄ．Ｋｅｙｗｏｒｄｓ：ｓｏｃｉａｌｅｃｏｌｏｇｙ,ｅｃｏｌ     

Mechanism of selective stabilization of extrinsic polypeptides in PSII particles by glycinebetaine

Ｔｈｒｅｅｅｘｔｒｉｎｓｉｃｐｏｌｙｐｅｐｔｉｄｅｓ,ｗｈｉｃｈａｒｅｌｏｃａｔｅｄｏｎｔｈｅｉｎｎｅｒｓｕｒｆａｃｅｏｆｔｈｙｌａｋｏｉｄｍｅｍｂｒａｎｅ,ｐｌａｙｅｓｓｅｎｔｉａｌｒｏｌｅｓｉｎｍａｉｎｔａｉｎｉｎｇｔｈｅｐｈｏｔｏｓｙｎｔｈｅｔｉｃｅｖｏｌｕｔｉｏｎｏｆｏｘｙｇｅｎ.Ｔｈｅｙａｒｅｇｅｎｅｒａｌｌｙｒｅｃｏｇｎｉｚｅｄａｓｌｉａｂｌｅｃｏｍｐｏｎｅｎｔｓｏｆｔｈｅｐｈｏｔｏｓｙｎｔｈｅｔｉｃａｐｐａｒａｔｕｓ,ａｎｄｃａｎｂｅｒｅｌｅａｓｅｄｂｙａｖａｒｉｅｔｙｏｆｐｈｙｓｉｃ…     

Attenuation of seizure in P77PMC rats with an HSV-vector expressing IL-1ra in brain

Ｅｐｉｌｅｐｓｙｉｓｏｎｅｏｆｔｈｅｃｏｍｍｏｎｄｉｓｅａｓｅｓｄｕｒｉｎｇｃｈｉｌｄｈｏｏｄｉｎｃｌｉｎｉｃａｌｐｒａｃｔｉｃｅ.Ｂｅｃａｕｓｅｏｆｃｏｍｐｌｅｘｅｔｉｏｌｏｇｙ,ｍｏｌｅｃｕｌａｒｍｅｃｈａｎｉｓｍｓｏｆｅｐｉｌｅｐｔｏｇｅｎｅｓｉｓａｒｅｎｏｔｆｕｌｌｙｃｌｅａｒ.Ａｓｗｅｋｎｏｗｅｐｉｌｅｐｓｙｉｓｃａｕｓｅｄｂｙｉｍｂａｌａｎｃｅｂｅｔｗｅｅｎｅｘｃｉｔａｔｉｏｎａｎｄｓｕｐｐｒｅｓｓｉｏｎｏｆｔｈｅｂｒａｉｎ.Ｉｔｈａｓｂｅｅｎｓｈｏｗｎｉｎｈｕｍａｎａｎｄａｎｉｍａｌｍ…     

农业生态学在我国发展的回顾与展望

农业生态学在我国发展的回顾与展望骆世明（华南农业大学,广州５１０６４２）ＲｅｖｉｅｗａｎｄＰｅｒｓｐｅｃｔｉｖｅｏｎＤｅｖｅｌｏｐｍｅｎｔｏｆＡｇｒｏｅｃｏｌｏｇｙＣｈｉｎａ．￥ＬｕｏＳｈｉｍｉｎｇ（ＳｏｕｔｈＣｈｉｎａＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖｅｒｓｉｔｙ,Ｇｕａｎｇｚｈｏｕ５１０６４２）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（２）：４－６．Ｉｎｌａｓｔｄｅｃａｄｅ,ｇｒｅａｔｐｒｏｇｒｅｓｓｈａｓｂｅｅｎｍａｄｅｉｎｔｈｅｔｅａｃｈｉｎｇａｎｄｒｅｓｅａｒｃｈｏｆａｇｒｉｃｕｌｔｕｒａｌｅｃｏｌｏｇｙｉｎＣｈｉ－ｎａ,ｂｕｔｓｏｍｅｏｂｓｔａｃｌｅｓｓｔｉｌｌｅｘｉｓｔｏｎｈｏｗｔｏｕｎｄｅｒｓｔａｎｄａｇｒｏｅｃｏｌｏｇｙ．Ｉｆｗｅｃａｎｒｅｃｏｇｎｉｚｅｔｈｅｓｏｃｉａｌｄｅ－ｍａｎｄｏｆａｇｒｏｅｃｏｌｏｇｙａｎｄｉｔｓｐｏｓｉｔｉｏｎｉｎａｇｒｉｃｕｌｔｕｒａｌｓｃｉｅｎｃｅａｎｄｐａｙａｔｔｅｎｔｉｏｎｔｏｔｈｅｄｅｓｃｒｉｐｔｉｏｎ,ａｓｓｅｓｓ－ｍｅｎｔ,ｅｘｐｅｒｉｍｅｎｔａｎｄａｎａｌｙｓｉｓｏｆａｇｒｏｅｃｏｓｙｓｔｅｍｍｏｄｅｌｓ,ｔｈｅｑｕａｎｔｉ     

Expression and regulation of hFIX minigene and cDNA driven by β-casein gene in mouse mammary gland

Ｉｎｒｅｃｅｎｔｙｅａｒｓ,ｔｈｅｒｅｓｅａｒｃｈｏｆｕｓｉｎｇｍａｍｍａｒｙｇｌａｎｄｂｉｏｒｅａｃｔｏｒｓｔｏｐｒｏｄｕｃｅｌａｒｇｅａｍｏｕｎｔｓｏｆｈｕｍａｎｐｈａｒｍａｃｅｕｔｉｃａｌｐｒｏｔｅｉｎｓｄｒａｗｍｏｒｅａｎｄｍｏｒｅａｔｔｅｎｔｉｏｎｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｔｒａｎｓｇｅｎｉｃｔｅｃｈｎｉｑｕｅｓ.Ｔｒａｎｓｇｅｎｅｅｘｐｒｅｓｓｉｏｎｉｎｍｉｌｋｏｆｆｅｒｓｓｅｖｅｒａｌｐｏｔｅｎｔｉａｌａｄｖａｎｔａｇｅｓ:ｐｒｏｔｅｉｎｓｓｅｃｒｅｔｅｄｉｎｍｉｌｋ,ｗ…     

Cloning of α-amylase gene from Schwanniomyces occidentalis and expression in Saccharomyces cerevisiae

Ａｎｏｒｇａｎｉｓｍ,Ｓ.ｃｅｒｅｖｉｓｉａｅｗｉｄｅｌｙｕｓｅｄｉｎｂｒｅｗｉｎｇ,ｂａｋｉｎｇａｎｄｉｎｅｔｈａｎｏｌｐｒｏｄｕｃｔｉｏｎｐｒｏｃｅｓｓｅｓｉｓｎｏｔａｂｌｅｔｏｈｙｄｒｏｌｙｓｅｓｔａｒｃｈ.ＴｈｕｓｔｈｅｔｒａｄｉｔｉｏｎａｌｃｏｎｖｅｒｓｉｏｎｏｆｓｔａｒｃｈｉｎｔｏｅｔｈａｎｏｌａｎｄＣＯ2ｄｅｐｅｎｄｓｏｎｔｈｅａｄｄｉｔｉｏｎｏｆｔｈｅｅｎｚｙｍｅｓｐｒｉｏｒｔｏｆｅｒｍｅｎｔａｔｉｏｎ,ｗｈｉｃｈｌｅａｄｓｔｏｌｉｑｕｉｆｉｃａｔｉｏｎａｎｄｓａｃｃｈａｒｉｆｉｃａｔ…     

A Study of the Lithic Assemblage from Zhoukoudian Locality 15

1　ＩｎｔｒｏｄｕｃｔｉｏｎＺｈｏｕｋｏｕｄｉａｎＬｏｃａｌｉｔｙ 1 5ｗａｓｆｏｕｎｄｉｎ 1 932ａｎｄｅｘｃａｖａｔｅｄｉｎ 1 935— 1 937.ＩｔｉｓｏｎｅｏｆｔｈｅｒｉｃｈｅｓｔｌｏｃａｌｉｔｉｅｓｉｎｔｈｅＺｈｏｕｋｏｕｄｉａｎｃｏｍｐｌｅｘａｎｄａｖｅｒｙｉｍｐｏｒｔａｎｔｌａｔｅＭｉｄｄｌｅＰｌｅｉｓｔｏｃｅｎｅａｒｃｈｅｏｌｏｇｉｃａｌｓｉｔｅｉｎＮｏｒｔｈＣｈｉｎａａｎｄｇｒｅａｔｅｒＥａｓｔＡｓｉａ .Ｈｏｗｅｖｅｒ,ｔｈｅｒｉｃｈｕｎｅａｒｔｈｅｄｍａｔｅｒｉａｌｓ ,ｉｎｃｌｕｄｉｎｇｍｏｒｅｔｈａｎ 1 0 0 0 0ｓｔｏｎｅａｒｔｉｆａｃｔｓａｎｄｂｏｎｅｓｏｆａｔｌｅａｓｔ 33ｍａｍｍａｌｉａｎｓｐｅｃｉｅｓ ,ｈａｖｅｒｅｍａｉｎｅｄｉｎａｃｃｅｓｓｉｂｌｅｔｏｒｅｓｅａｒｃｈｅｒｓｓｉｎｃｅｔｈｅ 1 94 0ｓ ,ａｎｄｔｗｏｐａｒｔｉａｌｒｅｐｏｒｔｓ[1— 2 ] ｐｕｂｌｉｓｈｅｄｉｎｔｈｅ 1 930ｓｈａｖｅｂｅｅｎｔｈｅｏｎｌｙｏｒｉｇｉｎａｌｓｔｕｄｉｅｓｏｆｔｈｅｓｉｔｅｆｏｒａｌｏｎｇｔｉｍｅ .Ｉｎ 1 997,ｔｈｅａｕｔｈｏｒｃａｒ...     

西藏生态农业探讨

西藏生态农业探讨刘明允,王德亭（西藏农牧学院,八一８５０４００）ＥｃｏｌｏｇｉｃａｌＡｇｒｉｃｕｌｔｕｒｅｉｎＴｉｂｅｔ￥．ＬｉｕＭｉｎｇｙｕｎ;Ｗａｎｇｂｅｔｉｎｇ（ＴｉｂｅｉＣｏｌｌｅｇｅｏｆＡｇｒｉｃｌｄｔｕｒａｌａｎｄＡｎｉｍａｌＨｕｓｂｏｎｄｒｙ,８５０４００）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（３）：７３－７５．Ｉｎｔｈｉｓｐａｐｅｒ,ｆｏｕｒｂａｓｉｃｐｒｉｎｃｉｐｌｅｓｃｏｎｃｅｒｎｉｎｇｔｈｅｃｏｎｓｅｒｖａｔｉｏｎｏｆｅｃｏｌｏｇｉｃａｌａｇｒｉｃｕＩｔｕｒｅｉｎＴｉｂｅｔａｒｅｐｕｔｆｏｒｗａｒｄａｎｄｓｏｍｅｃｈａｒａｃｔｅｒｉｓｔｉｃｓａｎｄｏｐｅｒａｔｅｄａｇｒｏｔｅｃｈｎｉｑｕｅｓｏｆＴｉｂｅ＇ｓｅｃｏｌｏｇｉｃａｌａｇｒｉｃｕＩｔｕｒｅａｒｅｓｕｍｍａ－ｒｉｚｅｄ．Ｂａｓｅｄｏｎｔｈｅｓｅ,ａｇｒｏ－ｅｃｏｓｙｓｔｅｍｓｉｎＴｉｂｅｔａｒｅｃｌａｓｓｉｆｉｅｄｉｎｔｏｔｗｏｇｒｏｕｐｓ,ｉ．ｅ．,ｔｅｍｐｅｒａｔｅ－ｈｕｍｉｄｆｏｒｅｓｔｒｙ－ａｇｒｉｃｕｌｔｕｒｅ·ａｎｉｍａｌｈｕｓｂａｎｄｒｙｃｏｍｂｉｎｅｄｅｃｏｓｙｓｔｅｍａｎｄａｒｉｄ－     

西双版纳热带季节雨林凋落叶分解与土壤动物群落：两种网孔分解袋的分解实验比较

 以西双版纳热带湿性季节沟谷雨林混合凋落叶作为分解基质,在不同位置季节雨林样地,采用不同网孔（ 2和0.15 mm）分解袋,开展大中型土壤动物对雨林凋落叶分解影响的实验,测定了不同网孔分解袋土壤动 物多样性、凋落叶分解速率和主要养分元素释放状况。结果显示：2 mm网孔分解袋土壤动物类群相对密度 年均值为2.67～2.83目•g－1凋落物干重,个体相对密度年均值为22.3～21.77个•g－1凋落物干重,显著 高于0.15 mm网孔分解袋的类群相对密度0.27～0.28目•g－1凋落物干重和个体相对密度2.88～2.77个•g－ 1凋落物干重（p<0.01）,并且0.15 mm网孔分解袋中极少量的动物个体主要为小型类群弹尾目和蜱螨目（ 原生动物、湿生土壤动物线虫不计）,由此我们视2 mm网孔分解袋凋落叶分解由绝大多数土壤动物和其它 土壤生物共同作用,而0.15 mm网孔分解袋基本排除了大中型土壤动物对袋内凋落叶分解的影响。2 mm网 孔分解袋凋落叶物质失重率（71%左右）、分解率指数（1.88～2.44）和主要养分元素释放率明显高于 0.15 mm分解袋（34%～35%,0.48～0.58）。通过比较两种不同网孔分解袋凋落叶失重率和元素释放率的 差异,显示出季节雨林大中型土壤动物群落对凋落叶物质损失的贡献率为年均值46%左右,并使凋落叶C/N 和C/P明显降低,而对不同元素释放率的影响不同,其中对N、S和Ca元素释放率的影响较大,而对K素释放 的影响作用最小。相关分析显示,2 mm网孔分解袋内土壤动物群落类群和个体的相对密度与凋落叶物质残 留率有较好的负相关关系,而群落香农多样性指数与凋落叶分解率指数表现出一定的正相关关系。     

川西亚高山森林凋落物分解初期土壤动物对红桦凋落叶质量损失的贡献

2010年10月26日-2011年4月18日在川西亚高山地区季节性冻融期间,选择典型的红桦-岷江冷杉林,采用凋落物分解袋法调查了不同网孔(0.02、0.125、1和3 mm)凋落物分解袋内的凋落物质量损失,分析微型、中型和大型土壤动物对红桦凋落叶分解的贡献.结果表明:在季节性冻融期间,0.02、0.125、1和3 mm分解袋内的红桦凋落叶质量损失率分别为11.8％、13.2％、15.4％和19.5％,不同体径土壤动物对红桦凋落叶质量损失的贡献率为39.5％;不同孔径凋落物袋内土壤动物的类群和个体相对密度与凋落叶的质量损失率的变化趋势相对一致.在季节性冻融的初期、深冻期和融化期,不同土壤动物对红桦凋落叶质量损失的贡献率为大型土壤动物(22.7％)＞中型土壤动物(11.9％)＞微型土壤动物(7.9％).季节性冻融期间土壤动物活动是影响川西亚高山森林凋落物分解的重要因素之一.     

宁夏荒漠草原柠条锦鸡儿枯落物分解特征及其影响因素

以宁夏荒漠草原柠条锦鸡儿(Caragana kornshinskii)枯落物为研究对象,利用网孔分解袋法研究了极小型、小型、中型和大型柠条锦鸡儿灌丛微生境枯落物分解率变化特征及对土壤环境的响应规律。结果表明:(1)随着分解时间延长,不同大小柠条锦鸡儿灌丛微生境土壤含水量和土壤温度均呈现出相似的分布特征,而土壤pH值和电导率随时间分布特征则受到灌丛大小的显著影响。(2)3种网孔内,不同大小柠条灌丛微生境间枯落物分解率均无显著差异性。但是,灌丛微生境中枯落物分解率受到灌丛大小和网孔大小的共同影响。(3)中型灌丛微生境中枯落物分解率在3种网孔间均无显著差异性。但在极小型灌丛微生境中,120 d时枯落物分解率表现为4 mm(40.95%)0.01 mm(38.51%)2 mm(32.14%),150 d时枯落物分解率表现为2 mm(37.64%)4 mm(35.20%)0.01 mm(26.68%)。在小型灌丛微生境中,120 d时枯落物分解率表现为0.01 mm(46.81%)4 mm(41.07%)2 mm(34.75%)。在大型灌丛微生境中,120 d时枯落物分解率表现为4 mm(39.65%)2 mm(36.65%)0.01 mm(35.96%),210 d时枯落物分解率表现为2 mm(48.05%)4 mm(35.96%)0.01 mm(30.80%)。(4)Olson衰减指数模型得出枯落物分解50%和95%所需时间,表现为极小型灌丛和中型灌丛微生境中均为0.95年和4.1年(3种网孔相同);小型灌丛微生境中为0.63年和2.74年(4 mm)、1.90年和8.21年(2 mm)、0.95年和4.1年(0.01 mm);大型灌丛微生境中为0.95年和4.1年(4 mm)、0.63年和2.74年(2 mm)、1.90年和8.21年(0.01 mm)。研究表明,在宁夏荒漠草原,仅灌丛大小引起的微生境差异对枯落物分解率影响较小,但灌丛大小和土壤动物类群的相互作用对枯落物分解率的影响较大。     

粤北地区溪流中的树叶分解及大型底栖动物功能摄食群

利用2种孔径(5mm的塑料网袋和0.1mm的布袋)的分解网袋对2种树叶在广东北部的横石水河的3级溪流中,进行了为期101d的树叶分解研究.结果表明:人面子树叶在网袋和布袋中的分解速率分别为0.0247d-1和0.0151d-1;而蒲桃树叶的分解速率则分别为0.0108d-1和0.0095d-1.说明2种树叶在布袋中的分解速率均比网袋慢,且人面子树叶的分解速率比蒲桃树叶快.定殖在2种树叶网袋中的功能摄食群以刮食者的比例最高(36%),其次是集食者(33%)和捕食者(25%),撕食者的比例最低(6%).在实验中后期,人面子树叶上的底栖动物个体总数、优势类群数和密度显著高于蒲桃树叶.说明在亚热带地区的中等级别的溪流中,由于撕食者种类减少,刮食者的类群数及密度对树叶分解速率具有显著影响.对微生物活动的抑制作用和对底栖动物取食的驱避作用使富含单宁成分的蒲桃树叶的分解速率下降.     

In situ studies on the breakdown ofNymphoides peltata (Gmel.) O. Kuntze (Menyanthaceae); Some methodological aspects of the litter bag technique

Summary Thein situ breakdown ofNymphoides peltata (Gmel.) O. Kuntze has been studied with special attention for methodology by: (1) using fresh and pre-dried material to establish the influence of pre-drying on breakdown and losses of nutrient stocks during decomposition; (2) enclosing different amounts of material in litter bags; (3) using litter bags with different mesh sizes, and (4) placing litter bags in water (floating leaves, petioles), on the sediment (long shoots) and in the hydrosoil (short shoots, roots). Of the material incubated in water, the floating leaves decomposed at a faster rate than the petioles, while the long shoots had the slowest breakdown. In the sediment the short shoots disappeared at a faster rate than the roots. By incubating the same morphological structure, both in the water and the sediment it appeared that the rate of breakdown was faster in the upper layers of the sediment. Pre-dried plant parts showed in water a larger initial weight loss than normal senescent plant parts, while in the sediment dried plant parts had a significantly slower loss of mass than the freshly incubated structures. Losses of nutrient stocks during decomposition were also markedly altered by pre-drying the material. When a larger amount ofNymphoides material was enclosed in the bags a tendency of a faster decay could be demonstrated. Macro-invertebrates colonized the litter bags with the 0.5 mm mesh size but usually could not-enter the 0.25 mm mesh size bags. The browsing of the detritivores did not result in a faster disappearance of organic matter, but organic matter must have been transported into the bags resulting in a larger amount of remaining organic matter when compared with the 0.25 mm mesh size bags.     

Decomposition of cellulose,soil organic matter and plant litter in a temperate grassland soil

The formation of mor humus in an experimental grassland plot, which has been acidified by long-term fertiliser treatment, has been studied by comparing the rates of cellulose, soil organic matter and plant litter decay with those in an adjacent plot with near-neutral pH and mull humus. The decomposition of cellulose filter paper in litter bags of 5 mm, 1-mm and 45-μm mesh size buried at 3 to 4 cm depth the plots was followed by measuring the weight loss and changes in glucose content over a 6 month period. Soil pH was either 5.3 or 4.3. Decomposition of native soil organic matter and plant litter in soil from the same plots were followed using CO₂ evolution in laboratory microcosms. Cellulose weight loss at pH 5.3 was greatest from the 5-mm mesh bags and least from the 45-um mesh bags. At pH 4.3 there was little weight loss from bags and no significant differences in weight loss between bags with different sized mesh. There was, however, a reduction in the glucose content of the hydrolysed and derivatised filter paper with time. The decomposition rate of native soil organic matter in the low pH soil was increased to that observed in the less acid soil when the pH of the former was increased from 4.3 to 5.3. The increase in decomposition rate of added plant litter in the more acid soil as a result of CA(OH)₂ addition was only 60% of that observed in the soil with pH 5.3. These data support the hypothesis that the absence of soil animals and the restricted microbial decomposition in the acidic soil was responsible for mor humus formation.     

Effects of water quality on habitat use by lesser scaup (Aythya affinis) broods in the boreal Northwest Territories, Canada

The dynamics of Rhizophora mangle litter production and decomposition were studied in a tropical coastal lagoon on the Gulf of Mexico in Veracruz, Mexico over a year (October 2002–October 2003). This region is characterized by three seasons: northerly winds (called ‘nortes’), dry, and rainy. Annual litter production (1116 g m⁻²) followed a seasonal pattern with leaf litter as the main fraction (70%) with two peaks in the dry and one in the rainy season. Leaf decomposition was evaluated with two types of litter bag in each season: fine mesh (1×1 mm) and coarse mesh (3×7 mm). Decomposition data were adjusted to a single negative exponential model. The results indicated faster decomposition rates in the coarse litter bag and significant differences among seasons. However these differences occurred after the 60th day of decomposition, indicating that leaching and microbial action were responsible for more than 50% of mass loss. After this period, the effects of aquatic invertebrates were evident but depended on climatic conditions. In the rainy season, the gastropod Neritina reclivata was associated with increasing leaf decomposition rate. In the ‘nortes’ season, the effect of aquatic invertebrates was smaller, and there were no differences in the decay constants calculated for the two litter bag types. High litter production represents an important input of organic matter which, through decomposition, may represent an important source of C, N, and P in this aquatic system.     

川西高山林线交错带土壤动物对岷江冷杉和高山杜鹃凋落物分解的贡献

土壤动物是调控凋落物分解的重要生物因素.为了探究川西高山林线交错带土壤动物对两个优势物种岷江冷杉和高山杜鹃凋落物分解的贡献,在3个海拔梯度(针叶林-林线-高山草甸)采用凋落物分解袋试验,通过不同孔径的网袋(0.04 mm,基本排除土壤动物;3 mm,允许土壤动物通过),研究了分解554 d(2013年5月—2014年11月)土壤动物对凋落物的影响.结果表明: 在整个林线交错带上,岷江冷杉的分解速率(k)为0.209～0.243,高山杜鹃的k为0.173～0.189,岷江冷杉的k大于高山杜鹃.土壤动物的参与显著加速了两种凋落叶分解,同时土壤动物对两种凋落物分解的作用和贡献随海拔升高而降低.自针叶林、高山林线至高山草甸,土壤动物对岷江冷杉分解的质量损失率为15.2%、13.2%、9.8%,对高山杜鹃分解的质量损失率为20.1%、17.5%、12.4%;土壤动物对岷江冷杉分解的平均日贡献率为0.17%、0.13%、0.12%,对高山杜鹃分解的平均日贡献率为0.26%、0.25%、0.23%,土壤动物对高山杜鹃的分解影响相对较大.海拔、凋落物自身性质及其交互作用对土壤动物作用下凋落物的质量损失率和贡献率均表现出显著影响.土壤动物的作用于岷江冷杉和高山杜鹃分解的平均日贡献率在当年生长季(0.25%和0.44%)和次年生长季(0.10%和0.19%)均高于雪被期(0.07%和0.12%).回归分析表明,环境因子(日平均气温、冻融循环次数以及雪被厚度)可以解释土壤动物作用于岷江冷杉和高山杜鹃质量损失率的42.7%和50.9%,贡献率的43.2%和55.6%,这对了解土壤动物在凋落物分解中的作用和深入认识高山生态系统物质循环具有重要意义.     

Root growth and litter decomposition in a coffee plantation under shade trees

In a non-fertilized coffee plantation under shade trees the root biomass was excavated to estimate its distribution in the soil profile. One third of total fine (less than 1 mm) roots was found in the first 10 cm of soil; the cumulative total to 30 cm reached 73%. A highly variable and transient amount of fine roots colonized the litter layer. Root production both in the litter and in the first 7.5 cm of mineral soil was estimated from sequential samplings and was 10 g m^–2 yr^–1 and 660 g m^–2 yr^–1 respectively. The decomposition rate of weighed averages of litter fractions in the coffee plantation, calculated as the ratio of litter fall rate to the amount found in the soil was k=4.8. Shade tree leaves, the major component of litter descomposed slower than coffee leaves and these slower than flowers and fruits. Litter bag experiments showed considerable slower rates when mesh was 0.03 mm than 0.5 mm. Nitrogen and phosphorous showed increases in concentrations as decomposition progressed while potassium, calcium and magnesium followed a decrease in concentration that paralleled that of dry weight loss. In comparing the decomposition rate for litter with or without coffee roots growing in the bags, a tendency to show faster decomposition rates was found for the treatment with roots. These differences were however, only significant for one month for shade tree leaves litter. Nitrogen amounts remaining in shade tree leaves litter was lower in the treatment with roots that without roots. Potassium concentration in roots was positively correlated with potassium concentration in decomposing leaf litter where roots were growing. These results suggest that while roots growing attached to decomposing litter had little or no effect in speeding the decomposition process, the superficial roots seem to play an important role in absorbing very efficiently the mineralized nutrients from litter. The anatomical study of roots showed that the plantation is intensely infected with V-A mycorrhiza. External mycorrhizal hyphae did not to play a role in attachment of roots to decomposing litter while root hairs were found to grow in profusion on root surfaces oriented toward litter.     

Highly reduced mass loss rates and increased litter layer in radioactively contaminated areas

The effects of radioactive contamination from Chernobyl on decomposition of plant material still remain unknown. We predicted that decomposition rate would be reduced in the most contaminated sites due to an absence or reduced densities of soil invertebrates. If microorganisms were the main agents responsible for decomposition, exclusion of large soil invertebrates should not affect decomposition. In September 2007 we deposited 572 bags with uncontaminated dry leaf litter from four species of trees in the leaf litter layer at 20 forest sites around Chernobyl that varied in background radiation by more than a factor 2,600. Approximately one quarter of these bags were made of a fine mesh that prevented access to litter by soil invertebrates. These bags were retrieved in June 2008, dried and weighed to estimate litter mass loss. Litter mass loss was 40 % lower in the most contaminated sites relative to sites with a normal background radiation level for Ukraine. Similar reductions in litter mass loss were estimated for individual litter bags, litter bags at different sites, and differences between litter bags at pairs of neighboring sites differing in level of radioactive contamination. Litter mass loss was slightly greater in the presence of large soil invertebrates than in their absence. The thickness of the forest floor increased with the level of radiation and decreased with proportional loss of mass from all litter bags. These findings suggest that radioactive contamination has reduced the rate of litter mass loss, increased accumulation of litter, and affected growth conditions for plants.