Litter evenness influences short-term peatland decomposition processes
Litter evenness influences short-term peatland decomposition processes
复制标题
DOI：
10.1007/s00442-010-1636-y
复制
发表时间：
2010-04
期刊：
影响因子：
2.7
通讯作者：
Susan E. Ward;N. Ostle;N. McNamara;R. Bardgett
中科院分区：
文献类型：
--
作者：
Susan E. Ward;N. Ostle;N. McNamara;R. Bardgett
人们担心气候和土地利用的变化可能会增加泥炭地的分解速度，导致储存的C释放到大气中。分解速度受温度和湿度等非生物因素的影响，但也受植被变化导致的凋落物质量变化等生物因素的影响。虽然凋落物物种特性和多样性对分解过程的影响得到了很好的研究，但物种相对丰度（均匀度）变化的影响受到的关注较少。在这项研究中，我们调查了短期泥炭地植物物种均匀度的变化对混合凋落物组合分解的影响，测量凋落物重量损失，呼吸CO2和渗滤液C和N。我们发现，在307天的潜伏期内，较高水平的物种均匀度增加了混合凋落物的分解率，以重量损失和渗滤液溶解有机氮来衡量。我们还发现，优势物种的身份影响的分解速率，衡量的重量损失，CO2通量和渗滤液N。最大的分解率时，矮生灌木Calluna vulgaris占主导地位的凋落物混合物，和最低的速率时，braditePleurozium schreberidominated。均匀度和优势种之间的相互作用也被检测到凋落物重量损失和渗滤液N。此外，积极的非加性效应混合凋落物观察到窝重量损失。我们的研究结果突出了英国泥炭地短期分解过程中植物群落组成均匀性变化的重要性。
There is concern that changes in climate and land use could increase rates of decomposition in peatlands, leading to release of stored C to the atmosphere. Rates of decomposition are driven by abiotic factors such as temperature and moisture, but also by biotic factors such as changes in litter quality resulting from vegetation change. While effects of litter species identity and diversity on decomposition processes are well studied, the impact of changes in relative abundance (evenness) of species has received less attention. In this study we investigated effects of changes in short-term peatland plant species evenness on decomposition in mixed litter assemblages, measured as litter weight loss, respired CO2and leachate C and N. We found that over the 307-day incubation period, higher levels of species evenness increased rates of decomposition in mixed litters, measured as weight loss and leachate dissolved organic N. We also found that the identity of the dominant species influenced rates of decomposition, measured as weight loss, CO2flux and leachate N. Greatest rates of decomposition were when the dwarf shrubCalluna vulgarisdominated litter mixtures, and lowest rates when the bryophytePleurozium schreberidominated. Interactions between evenness and dominant species identity were also detected for litter weight loss and leachate N. In addition, positive non-additive effects of mixing litter were observed for litter weight loss. Our findings highlight the importance of changes in the evenness of plant community composition for short-term decomposition processes in UK peatlands.