Effect of adeno-associated virus-mediated transfer of low density lipoprotein receptor gene on treatment of hypercholesterolemia

ＬＤＬＲｐｌａｙｓａｖｉｔａｌｒｏｌｅｉｎｅｌｉｍｉｎａｔｉｎｇｐｌａｓｍａｃｈｏｌｅｓｔｅｒｏｌ.ＫｎｏｃｋｉｎｇｏｕｔＬＤＬＲｇｅｎｅｃａｎｃａｕｓｅｈｙｐｅｒｃｈｏｌｅｓｔｅｒｏｌｅｍｉａ.Ｐｅｒｓｏｎｓｗｉｔｈｆａｍｉｌｉａｌｈｙｐｅｒｃｈｏｌｅｓｔｅｒｏｌｅｍｉａ(ＦＨ)ｈａｖｅｂｅｅｎｆｏｕｎｄｔｏｈａｖｅｇｅｎｅｔｉｃｄｅｆｅｃｔｓｉｎＬＤＬＲｇｅｎｅ.ＩｎｔｒｏｄｕｃｉｎｇＬＤＬＲｇｅｎｅｔｏｅｘｐｅｒｉｍｅｎｔａｌａｎｉｍａｌｓｗｉｔｈｈｙｐｅｒｃｈｏｌｅｓｔｅｒｏｌｅｍｉａｃｏｕ…     

广西石灰岩地区新植物

1　厚叶瑞香　新种　图 1 :1～ 2ＤａｐｈｎｅｐａｃｈｙｐｈｙｌｌａＤ .Ｆａｎｇ,ｓｐ .ｎｏｖ.Ｆｉｇ .1 :1～ 2ＡＤ .ｘｉｃｈｏｕｅｎｓｉＨ .Ｆ .ＺｈｏｕｅｘＣ .Ｙ .Ｃｈａｎｇｆｏｌｉｏｒｕｍｌａｍｉｎｉｓｃｏｒｉａｃｅｉｓｖｅｌｃｒａｓｓｅｃｏｒｉａｃｅｉｓｓａｅｐｅｉｎａｅｑｕｉｌａｔｅｒｉｓｓｉｃｃｏｓｕｐｒａｒｕｇｏｓｉｓｓｕｂｔｕｓｓｕｂｂｒｕｎｎｅｓｃｅｎｔｉｂｕｓｊｕｖｅｎｔｕｔｅｍａｒｇｉｎｅｄｅｎｓｅｃｉｌｉａｔｉｓ,ｂｒａｃｔｅｉｓｍａｊｏｒｉｂｕｓ1 0～ 1 6ｍｍｌｏｎｇｉｓｅｃｉｌ…     

Synergistic effects of focus ultrasound with different frequency and hematoporphyrin on human tumor cells

Ｐｈｏｔｏｄｙｎｅｓｔｉｃｔｈｅｒａｐｙ(ＰＤＴ)ｈａｓｂｅｅｎｅｘｔｒｅｍｅｌｙｗｅｌｌｓｔｕｄｉｅｄｓｉｎｃｅＤｏｕｇｈｅｒｔｙａｎｄｃｏｗｏｒｋｅｒｓｏｂｓｅｒｖｅｄｔｈｅｏｂｖｉｏｕｓａｎｔｉｔｕｍｏｒｅｆｆｅｃｔｏｆｔｈｅｃｏｍｂｉｎａｔｉｏｎｏｆｌａｓｅｒｗｉｔｈｈｅｍａｔｏｐｏｒｐｈｙｒｉｎ[1].Ａｎｄｉｔｈａｓｂｅｅｎｕｓｅｄｉｎｔｈｅｃｌｉｎｉｃｔｈｅｒａｐｙｆｏｒｈｕｍａｎｔｕｍｏｒｓ[2].Ｈｏｗｅｖｅｒ,ｔｈｅｌｉｇｈｔｈａｓｔｈｅｄｉｓａｄｖａｎｔａｇｅｏｆｐｏｏｒｐｅｎｅｔｒ…     

小麦醇溶蛋白盒结合因子基因启动子序列

1　Ｓｏｕｒｃｅ　Ｔｈｅｓｅｑｕｅｎｃｅｗａｓｄｅｔｅｒｍｉｎｅｄｆｒｏｍａｒｅ ｖｅｒｓｅＰＣＲｐｒｏｄｕｃｔ,ｗｈｉｃｈｗａｓｌｉｇａｔｅｄｔｏｐＭＤ1 8 Ｔｖｅｃｔｏｒ(ＴａＫａＲａＢｉｏｔｅｃｈｎｏｌｏｇｙＣｏ .) ,ｆｒｏｍｎｕｃｌｅａｒｇｅｎｏｍｉｃＤ     

内分泌疾病血浆氨基酸的模式

内分泌疾病血浆氨基酸的模式蒋滢,黄美英,何达纯ＰｌａｓｍａＦｒｅｅＡｍｉｎｏＡｃｉｄｉｎＥｎｄｏｃｒｉｎｅＤｉｓｅａｓｅｓ￥ＪｉａｎｇＹｉｎｇ;ＨｉｉａｎｇＭｅｉｙｉｎｇａｎｄＨｅＤａｃｈｕｎ（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｃｈｅｍｉｓｔｒｙ,Ｓｕｚ...     

沈阳市东陵区丘陵坡地坡面太阳直射光的分布及其分析

沈阳市东陵区丘陵坡地坡面太阳直射光的分布及其分析郭林海（中国科学院沈阳应用生态研究所,１１００１５）ＤｉｓｔｒｉｂｕｔｉｏｎｏｆＤｉｒｅｃｔＳｏｌａｒＲａｄｉａｔｉｏｎｏｎＨｉｌｌｙＳｌｏｐｅｓｏｆＤｏｎｇｌｉｎｇＤｉｓｔｒｉｃｔｏｆＳｈｅｎｙａｎｇＭｕｎｉｃｉｐａｌｉｔｙａｎｄＩｔｓＡｎａｌｙｓｉｓ￥ＧｕｏＬｉｎｈａｉ（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＥｃｏｌｏｇｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａ,Ｓｈｅｎｙａｎｇ１１００１５）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（１）：５９－６１．Ｂａｓｅｄｏｎｔｈｅｌａｔｅｓｔ１：５００００ｔｏｐｏｇｒａｐｈｉｃｍａｐ,ｔｈｅ１：１０００００ｓｌｏｐｅｇｒａｄａｔｉｏｎｍａｐｉｓｄｒａｗｎｏｕｔａｎｄａｒｅａｃａｌｃｕｌａｔｉｏｎｉｓｍａｄｅ．Ｔｈｅｄｉｒｅｃｔｓｏｌａｒｒａｄｉａｔｉｏｎｉｎｔｙｐｉｃａｌｓｉｔｅｓｏｆｔｈｅｄｉｓｔｒｉｃｔｉｓｍｅａｓｕｒｅｄａｎｄｃａｌｃｕｌａｔｅｄ,ａｎｄｔｈｅｖａｒｉａｔｉｏｎｃｕｒｖｅｓｏｆａｎｎｕａｌｆｌｕｘｏｆｄｉｒｅｃｔｓｏｌａｒｒａｄｉａｔｉｏｎｏｎｖａｒｉｏｕｓｓｌｏｐｅｄｉｒｅｃｔｉ     

大连潮间带底栖海藻群落的数量特征和优势种的季节变化

大连潮间带底栖海藻群落的数量特征和优势种的季节变化熊韶峻,王献平,郭旭光（辽宁师范大学生物系,大连１１６０２２）ＳｅａｓｏｎａｌＶａｒｉａｔｉｏｎｏｆＱｕａｎｔｉｔａｔｉｖｅＣｈａｒａｃｔｅｒｓａｎｄＤｏｍｉｎａｎｔＳｐｅｃｉｅｓｏｆＢｅｎｔｈｉｃＳｅａｗｅｅｄＣｏｍｍｕｎｉｔｉｅｓｗｉｔｈｉｎＩｎｔｅｒｔｉｄａｌｓｉｎＤａｌｉａｎ,Ｃｈｉｎａ￥．ＸｉｏｎｇＳｈａｏｊｕｎ,ＷａｎｇＸｉａｎｐｉｎｇ,ＧｕｏＸｕｇｕａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｌｏ－ｇｙ,ＬｉａｏｎｉｎｇＮｏｒｍａｌＵｎｉｕｅｒｓｉｔｙ,Ｄａｌｉａｎ１１６０２２）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（４）：２７－２９．Ｔｈｅｃｏｍｐｏｓｉｔｉｏｎ,ｃｏｖｅｒａｇｅ,ｂｉｏｒｎａｓｓａｎｄｄｏｒｎｉｎａｎｔｓｐｅｃｉｅｓｏｆｂｅｎｔｈｉｃｓｅａｗｅｅｄｃｏｒｎｍｕｎｌｔｙｗｉｔｈｉｎｉｎｔｅｒｔｉｄａｌｉｎＤａｌｉａｎ,ＣｈｉｎａｗｅｒｅｍｏｎｔｈｌｙｉｎｖｅｓｔｉｇａｔｅｄｆｒｏｒｎＭａｒｃｈ１９９０ｔｏＭａｒｃｈ１９９１．Ｉｔｉｓｘｈｏｗｎｔｈａｔ１）．ｔｈｅｇｅｎ－ｅｒａｌｔｅｎｄｅｎｃｙｏｆｓｅａｓｏ     

滕格里沙漠晚更新世湖相沉积介形类及其环境意义

腾格里沙漠晚更新世断头梁剖面分析出介形类７属７种,分别为Ｌｉｍｎｏｃｙｔｈｅｒｅ ｉｎｏｐｉｎａｔａ,Ｄａｒｗｉｎｕｌａ ｓｔｅｖｅｎｓｏｎｉ,Ｃａｎｄｏｎａ ｎｅｇｌｅｃｔａ,Ｃｙｐｒｉｄｅｉｓ ｔｏｒｏｓａ,Ｉｌｙｏｃｙｐｒｉｓ ｇｉｂｂａ,Ｃｙｃｌｏｃｙｐｒｉｓ ｓｅｒｅｎａ,？Ｎｅｏｃｙｐｒｉｄｏｐｓｉｓ ｓｐ．,其中Ｌｉｍｎｏｃｙｔｈｅｒｅ ｉｎｏｐｉｎａｔａ和Ｄａｒｗｉｎｕｌａ ｓｔｅ     

沈阳市东陵区景观生态潜力研究

沈阳市东陵区景观生态潜力研究赵羿,吴彦明（中国科学院沈阳应用生态研究所,１１００１５）邓百祥（辽宁省水利水电勘测设计研究院,沈阳１１０００６）ＥｃｏｌｏｇｉｃａｌＰｏｔｅｎｔｉａｌｏｆＬａｕｄｓｃａｐｅｉｎＤｏｎｇｌｉｎｇＤｉｓｔｒｉｃｔｏｆＳｈｅｎｙａｎｇ￥ＺｈａｏＹｉ;ＷｕＹａｎｍｉｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＥｃｏｌｏｇｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａ,Ｓｈｅｎｙａｎｇ１１００１５）,ＤｅｎｇＢａｉｘｉａｎｇ（ＬｉａｏｎｉｎｇＡｃａｄｅｍｙｏｆＷａｔｅｒＣｏｎ－ｓｅｒｖａｎｃｙａｎｄＷａｔｅｒＰｏｗｅｒＳｕｒｅｅｙｉｎｇａｎｄＤｅｓｉｇｎｉｎｇ,Ｓｈｅｎｙａｎｇ１１０００６）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（５）：１－８。Ｅｃｏｌｏｇｉｃａｌｐｏｔｅｎｔｉａｌｏｆｌａｕｄｓｃａｐｅｃｏｎｓｉｓｔｓｏｆｉｔｓｐｒｏｄｕｃｔｉｖｅｐｏｔｅｎｔｉａｌ,ｅｃｏｌｏｇｉｃａｌｐｏｔｅｎｔｉａｌａｎｄｐｒｉｃｅｌｅｓｓｐｏ－ｔｅｎｔｉａｌ．Ｔｈｒｏｕｇｈｃａｌｃｕｌａｔｉｎｇｄｉｆｆｅｒｅｎｔｐｒｏｄｕｃｔｉｖｅｐｏｔｅｎｔｉａｌｓ（ｐｈｏｔｏｓｙｎｔｈｅｔｉｃｐｏｔ     

DIFFERENT RESULTS BY DIFFERENT COMMERCIAL TAQ DNA POLYMERASE IN RAPD

ＲＡＰＤ (ＲａｎｄｏｍＡｍｐｌｉｆｉｅｄＰｏｌｙｍｏｒｐｈｉｃＤＮＡ )ｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎｗｉｄｅｌｙｕｓｅｄｉｎａｎｉｍａｌ,ｐｌａｎｔ,ｈｕｍａｎａｎｄｍｉｃｒｏｏｒｇａｎｉｓｍｒｅｓｅａｒｃｈｓｉｎｃｅｉｔｗａｓｆｉｒｓｔｅｓｔａｂｌｉｓｈｅｄｂｙＷｉｌｌｉａｍｓｉｎ 1 990 [1-3 ] .Ｂｕｔ,ｂｅｃａｕｓｅｏｆｌｏｗａｎｎｅａｌｅｄｔｅｍｐｅｒａｔｕｒｅａｎｄｓｈｏｒｔ1 0 -ｎｔｐｒｉｍｅｒｓ,ｔｈｅｒｅｓｏｌｕｔｉｏｎａｎｄｒｅｐｅｔｉｔｉｏｎｉｓｌｏｗｉｎＲＡＰＤ .Ｔｈｅｓｔａｂｉ…     

云冷杉天然林乔木树种组成及物种多样性对择伐强度的动态响应

以吉林省长白山金沟岭林场云冷杉天然林为研究对象,定量分析不同择伐强度(对照0%、弱度择伐20.6%、中度择伐29.9%和重度择伐41.6%)下其乔木层树种组成及物种多样性的动态变化规律。结果显示:采伐后经10年恢复,择伐对原有林分结构影响不大,其中弱度和中度择伐仍能保持择伐前以冷杉占优势、红松和云杉占亚优势的物种结构,重度择伐使林分结构略有改变,但不明显;相比择伐前,择伐后经10年恢复的样地α多样性指数均有所增加,优势度指数均有不同程度的降低,其中弱度择伐样地的物种丰富度指数、多样性指数及均匀度指数的增加量和优势度指数的减少量均最大,说明弱度择伐有利于改善林分物种多样性状况,使林分物种更为丰富。本研究结果表明采取弱度择伐的方式更有利于维持林分物种结构及物种多样性,有利于云冷杉天然林的可持续经营和发展。     

人为干扰对风水林群落林下木本植物组成和多样性的影响

华南地区的风水林是乡村聚落的一种特色林分, 具有守护村庄的象征意义。在过去的数百年中, 风水林在乡村的社会文化习俗的影响下而受到保护, 对当地的生物多样性保育有着重要作用。为揭示人为干扰对风水林的影响, 我们选择广东省东莞市大岭山镇同一林分起源的3个具有相似地形的风水林, 研究了在不同干扰强度下其林下木本植物种类组成和物种多样性。多响应置换过程(multi-response permutation procedures, MRPP)分析表明, 人为干扰显著改变了风水林林下木本植物组成(P = 0.001, A = 0.3886), 沿着干扰由弱至强的梯度呈现出中生性植物减少、阳生性植物递增的趋势。多样性指数变化趋势为重度干扰＞中度干扰＞轻度干扰, 但没有表现出统计学意义上的差异(P＞0.05)。随着干扰强度的增大, 3个风水林群落相互间的林下物种相似性降低, 物种替代率呈增加趋势。双向聚类分析较好地反映出林下物种因受不同人为干扰强度影响而表现出在空间分布上的差异。指示种分析进一步确定了不同干扰强度下具有显著指示值(IV ≥60)的指示种。综合分析表明, 人为干扰有利于阳性物种在风水林内定居生长, 并明显地改变了林下木本植物组成, 但未能引起物种多样性的显著差异。此外, 找出对人为干扰产生关键生态响应的林下指示种, 对增进风水林的生物多样性保育以及生态系统管理有着重要的理论意义和实践价值。     

天然林不同强度择伐后林分空间结构变化动态

基于长期跟踪复测数据,利用混交度、大小比数和角尺度3个结构参数,研究了4种不同强度择伐(弱度13.O％、中度29.1％、强度45.8％、极强度67.1％)后天然林林分空间结构的变化动态.结果表明:弱度和中度择伐后林分平均混交度和大小比数呈增长趋势,强度和极强度择伐则呈下降趋势;择伐并未改变林木的空间分布格局,各样地林分均为聚集分布,中度择伐处于随机分布状态的林木数大幅增加.总的来说,弱度和中度择伐后林分空间结构正趋向优化.     

择伐强度对天然次生林乔木层6种优势种群生态位的影响

为探讨择伐强度对天然次生林乔木优势树种生态位的影响,运用定量分析方法对不同强度择伐下6种乔木优势树种[马尾松(Pinus massoniana)、木荷(Schima superba)、虎皮楠(Daphnipyllum oldhamii)、米槠(Castanopsis carlesii)、甜槠(C. eyrei)、黄瑞木(Adinandra millettii)]的生态位宽度、生态位相似性比例和生态位重叠进行了测定。结果表明：择伐干扰下,优势种群的生态位宽度随择伐强度增大呈下降趋势;除黄瑞木外,其余5种优势树种的生态位宽度均大于0.5;生态位重叠值大于0.8的种对比例,也随择伐强度增大而下降。在皆伐干扰下,优势种群的生态位宽度均小于0.5,生态位重叠值大于0.8的种对比例仅占46.7%。这说明适度择伐(弱度和中度择伐)干扰,有利于保持优势种群在群落中的较大生态位宽度和较强生态适应性。因此,合理择伐有利于中亚热带天然次生林的保护和利用,择伐强度应以弱度或中度为宜。     

Species and structural diversity of church forests in a fragmented Ethiopian Highland landscape

Question: Thousands of small isolated forest fragments remain around churches (“church forests”) in the almost completely deforested Ethiopian Highlands. We questioned how the forest structure and composition varied with altitude, forest area and human influence. Location: South Gondar, Amhara National Regional State, Northern Ethiopia. Methods: The structure and species composition was assessed for 810 plots in 28 church forests. All woody plants were inventoried, identified and measured (stem diameter) in seven to 56 10 m x 10‐m plots per forest. Results: In total, 168 woody species were recorded, of which 160 were indigeneous. The basal area decreased with tree harvest intensity; understorey and middle‐storey density (<5 cm DBH trees) decreased with grazing; overstorey density (>5 cm DBH trees) increased with altitude. The dominance of a small set of species increased with altitude and grazing intensity. Species richness decreased with altitude, mainly due to variation in the richness of the overstorey community. Moreover, species richness in the understorey decreased with grazing intensity. Conclusions: We show how tree harvesting intensity, grazing intensity and altitude contribute to observed variations in forest structure, composition and species richness. Species richness was, however, not related to forest area. Our study emphasizes the significant role played by the remaining church forests for conservation of woody plant species in North Ethiopian Highlands, and the need to protect these forests for plant species conservation purposes.     

Long-Term Impacts of Fuelwood Extraction on a Tropical Montane Cloud Forest

Fuelwood extracted from natural forests serves as a principal energy source in rural regions of many tropical countries. Although fuelwood extraction (even low intensities) might strongly impact the structure and species composition of natural forests, long-term studies remain scarce. Here, we estimate the potential long-term impacts (over several hundred years) of such repeated harvesting of single trees on tropical montane cloud forest in central Veracruz, Mexico, by applying a process-based forest growth model. We simulate a wide range of possible harvesting scenarios differing in wood volume harvested and preferred tree species and sizes, and use a set of indicators to compare their impacts on forest size structure and community composition. Results showed that the overall impact on forest structure and community composition increased linearly with the amount of harvested wood volume. Even at low levels of harvesting, forest size structure became more homogeneous in the long term because large old trees disappeared from the forest, but these changes might take decades or even centuries. Although recruitment of harvested species benefited from harvesting, species composition shifted to tree species that are not used for fuelwood. Our results demonstrate that fuelwood extraction can have marked long-term impacts on tropical montane cloud forests. The results also offer the possibility to support the design of management strategies for the natural species-rich forests that achieve a balance between economic needs and ecological goals of the stakeholders. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Fire as a Recurrent Event in Tropical Forests of the Eastern Amazon: Effects on Forest Structure,Biomass, and Species Composition1

The effects of fire on forest structure and composition were studied in a severely fire-impacted landscape in the eastern Amazon. Extensive sampling of area forests was used to compare structure and compositional differences between burned and unburned forest stands. Burned forests were extremely heterogeneous, with substantial variation in forest structure and fire damage recorded over distances of <50 m. Unburned forest patches occurred within burned areas, but accounted for only six percent of the sample area. Canopy cover, living biomass, and living adult stem densities decreased with increasing fire inrensiry / frequency, and were as low as 10–30 percent of unburned forest values. Even light burns removed >70 percent of the sapling and vine populations. Pioneer abundance increased dramatically with burn intensity, with pioneers dominating the understory in severely damaged areas. Species richness was inversely related to burn severity, but no clear pattern of species selection was observed. Fire appears to be a cyclical event in the study region: <30 percent of the burned forest sample had been subjected to only one burn. Based on estimated solar radiation intensities, burning substantially increases fire susceptibility of forests. At least 50 percent of the total area of all burned forests is predicted to become flammable within 16 rainless days, as opposed to only 4 percent of the unburned forest. In heavily burned forest subjected to recurrent fires, 95 percent of the area is predicted to become flammable in <9 rain-free days. As a recurrent disturbance phenomenon, fire shows unparalleled potential to impoverish and alter the forests of the eastern Amazon.     

砂仁种植对热带雨林植物多样性的影响探讨

通过对各种不同状况的林下种植砂仁的热带雨林片断与同样类型的原始热带雨林的比较研究 ,探讨了砂仁种植对热带雨林植物多样性各个方面的影响。砂仁种植必须大量清除小树、林下幼树、灌木层植物 ,致使种植了砂仁的热带雨林片断的乔木下层及几乎整个的幼树、灌木层遭严重破坏 ,物种和个体大量流失 ,群落结构变得非常不稳定。由于热带雨林的更新主要依赖于其林下层的幼苗库 ,林下层的幼树、苗库被清除或破坏 ,热带雨林就难以自我更新 ,故林下种植砂仁的更大的潜在危害是使得热带雨林不能自我更新。种植了砂仁的热带雨林片断 ,物种和个体数的减少或流失 ,主要是直接的人为清除的结果 ,清除强度大 ,种类和个体减少就多。热带雨林下砂仁种植后 ,那些在原乔木层中占多数的只有 1～ 2个个体的脆弱种类 (种群 )将首先消失     

Chronosequential change in a butterfly community after clear-cutting of deciduous forests in a cool temperate region of central Japan

Transect counts of butterflies were conducted in the northern part of Ibaraki, central Japan, from 1997 to 2001 at 11 census sites, composed of successive stages of deciduous forest development: grassland (one site, early abandoned stage); cutover land (one site, 1–5 years after clear‐cutting); secondary forests (very young (two sites, 6–9 years), middle (two sites, 16–22 years) and old (two sites, 47–51 years)) and old‐growth natural forests (three sites, ≥124 years old). A total of 86 species and 8858 individual butterflies were recorded by 29 sets (406 times) of transect counts. The species richness (number of species), abundance (number of individuals) and diversity indices (Shannon–Wiener H′ and Simpson's 1–λ) of butterflies were high in the early stages (grassland, cutover land and very young secondary forests) of secondary succession. Typical natural forest species increased with the progress of succession, and the old secondary forests and old‐growth natural forests had similar species composition. In contrast, most of the typical natural grassland species were recorded only in the grassland site. In the cutover land site, the number of individuals of grassland species considerably decreased from the first to the second year; furthermore, only one typical natural grassland species was recorded. Thus, the suitable stage for grassland butterfly species lasts for only 1–2 years after clear‐cutting. Old secondary forests (approximately>50 years old) would be able to give refuge to the forest butterfly species, including typical natural forest species. Based on the results, a practical, forestry‐based plan to conserve butterfly diversity was proposed.     

Changes in Forest Structure and Species Composition during Secondary Forest Succession in the Bolivian Amazon1

Changes in forest structure and species diversity throughout secondary succession were studied using a chronosequence at two sites in the Bolivian Amazon. Secondary forests ranging in age from 2 to 40 years as well as mature forests were included, making a total of 14 stands. Fifty plants per forest layer (understory, subcanopy, and canopy) were sampled using the transect of variable area technique. Mean and maximum height, total stem density, basal area, and species number were calculated at the stand level. Species diversity was calculated for each stand and for each combination of forest layer and stand. A correspondence analysis was performed, and the relationship between relative abundance of the species and stand age was modeled using a set of hierarchical models. Canopy height and basal area increased with stand age, indicating that secondary forests rapidly attain a forest structure similar in many respects to mature forests. A total of 250 species were recorded of which ca 50 percent made up 87 percent of the sampled individuals. Species diversity increased with stand age and varied among the forest layers, with the lowest diversity in the canopy. The results of the correspondence analysis indicated that species composition varies with stand age, forest layer, and site. The species composition of mature forests recovered at different rates in the different forest layers, being the slowest in the canopy layer. Species showed different patterns of abundance in relation to stand age, supporting the current model of succession.