Variations in Oak Litter Quality Along an Urban-Rural Gradient and Effect on Leaf Litter Decomposition

橡树凋落物质量沿城乡梯度的变化及其对落叶分解的影响

• 批准号: 9110068
• 负责人: Margaret Carreiro
• 金额: $ 1.8万
• 依托单位: New York Botanical Garden
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1993-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9110068&HistoricalAwards=false
• 关键词: Variations; Oak; Litter; Quality; Along

Although air pollution and soil heavy metals are higher in New York than in rural sites, litter decomposition rates in oak forests located along an urban-rural gradient were surprisingly faster in urban sites. To determine whether differences in leaf quality contribute to faster decay rates of urban litter, Dr. Carriero will conduct a decomposition experiment on newly fallen oak leaves collected along the gradient and incubated in the laboratory. Since temperature, moisture, and microbial inoculum will be standardized, the experiment will directly assay whether the quality of living oak leaves has been changed enough in cities to result in more rapid decay after leaf fall. Dry weight loss of laboratory-incubated litter will be measured at intervals over a 4-month period. Growth and respiratory activity of fungi and bacteria colonizing litter will also be measured as decay progresses to determine responses to possible differences in leaf quality. An understanding of mechanisms behind the different litter decay rates in urban and rural forests is important since decomposition rates regulate nutrient flows within these ecosystems and influences nutrient availability to plants. The facilities available for conducting this research are first-rate. ***

虽然纽约的空气污染和土壤重金属高于农村地区，但位于城乡梯度上的橡树林的凋落物分解速度在城市地区出人意料地快。为了确定树叶质量的差异是否有助于加快城市凋落物的腐烂速度，卡里罗博士将对沿着梯度收集并在实验室培养的新落下的橡树叶进行分解实验。由于温度、湿度和微生物接种将被标准化，该实验将直接测试城市活橡树叶的质量是否发生了足够大的变化，从而导致落叶后更快的腐烂。实验室孵化仔猪的干重损失将在4个月内每隔一段时间测量一次。随着腐烂进程的进行，还将测量真菌和细菌在凋落物上的生长和呼吸活性，以确定对可能存在的叶质量差异的反应。了解城市和农村森林中不同凋落物腐解率背后的机制很重要，因为腐解率调节这些生态系统内的养分流动，并影响对植物的养分供应。可用于进行这项研究的设施是一流的。***