{"title":"Role of physical fragmentation and invertebrate activity in the breakdown rate of leaves","authors":"Verónica Ferreira, M. Graça, J. Lima, R. Gomes","doi":"10.1127/0003-9136/2006/0165-0493","DOIUrl":null,"url":null,"abstract":"We evaluated the relative importance of current velocity and invertebrate activities in the breakdown rate of alder (Alnus glutinosa (L.) Gaertner) leaves. Decomposition experiments were carried out in artificial channels, where current velo- city and shredder presence were manipulated, and in a 4 th order stream, in both summer and autumn, where litter bags were incubated in several reaches differing in both depth and current velocity. Alder leaves incubated in artificial channels decomposed signifi- cantly faster in the presence of shredders than in their absence (k = 0.0368/d vs. k = 0.0210/d in low current and k = 0.0472/d vs. k = 0.0219/d in high current). However, cur- rent (up to 2.35 m/s) had no significant effect on decomposition rates. In channels with- out invertebrates, no significant differences in k values were found between coarse and fine mesh bags in high (0.20 m/s) and low (0.05 m/s) current. Leaves incubated in the stream during summer, in reaches with current velocity ranging from 0.003 to 1.185 m/s, did not differ in their decomposition rates (k = 0.0489/d to k = 0.0645/d). In autumn, leaves exposed to high current (1.228 m/s) had faster decomposition rate (k = 0.0417/d vs. k = 0.0136/d), which may be related to sediment transport during this time of the year or to the tendency for higher number of shredders in high current-shallow reaches.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2006-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"100","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Archiv Fur Hydrobiologie","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1127/0003-9136/2006/0165-0493","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 100
Abstract
We evaluated the relative importance of current velocity and invertebrate activities in the breakdown rate of alder (Alnus glutinosa (L.) Gaertner) leaves. Decomposition experiments were carried out in artificial channels, where current velo- city and shredder presence were manipulated, and in a 4 th order stream, in both summer and autumn, where litter bags were incubated in several reaches differing in both depth and current velocity. Alder leaves incubated in artificial channels decomposed signifi- cantly faster in the presence of shredders than in their absence (k = 0.0368/d vs. k = 0.0210/d in low current and k = 0.0472/d vs. k = 0.0219/d in high current). However, cur- rent (up to 2.35 m/s) had no significant effect on decomposition rates. In channels with- out invertebrates, no significant differences in k values were found between coarse and fine mesh bags in high (0.20 m/s) and low (0.05 m/s) current. Leaves incubated in the stream during summer, in reaches with current velocity ranging from 0.003 to 1.185 m/s, did not differ in their decomposition rates (k = 0.0489/d to k = 0.0645/d). In autumn, leaves exposed to high current (1.228 m/s) had faster decomposition rate (k = 0.0417/d vs. k = 0.0136/d), which may be related to sediment transport during this time of the year or to the tendency for higher number of shredders in high current-shallow reaches.
我们评估了水流速度和无脊椎动物活动对桤木(Alnus glutinosa, L.)分解率的相对重要性。加特纳)树叶。在人工河道中进行了分解实验,其中控制了流速和碎纸机的存在,并在夏季和秋季在第4级河流中进行了分解实验,其中在几个深度和流速不同的河段孵育了垃圾袋。在人工通道中培养的桤木叶片,在有碎纸机的情况下,分解速度明显快于没有碎纸机的情况(k = 0.0368/d vs. k = 0.0210/d, k = 0.0472/d vs. k = 0.0219/d)。然而,电流(高达2.35 m/s)对分解速率没有显著影响。在无无脊椎动物的通道中,粗网袋和细网袋在高(0.20 m/s)和低(0.05 m/s)电流下的k值无显著差异。在流速为0.003 ~ 1.185 m/s的河段,夏季在溪流中孵育的叶片,其分解速率(k = 0.0489 ~ 0.0645/d)没有差异。在秋季,暴露在大电流(1.228 m/s)下的叶片分解速率更快(k = 0.0417/d vs. k = 0.0136/d),这可能与秋季泥沙输运有关,也可能与大电流浅水河段碎纸机数量较多有关。