SGER: Unpredictable Events of Catastrophic Proportions in Temparate Forest Ecosystems: Developing a Baseline to Assess Cascading Effects and Coupled Interactions

最近发展起来的生态学理论已确定重大干扰事件是大规模环境变化和演变的关键因素。 间断平衡和混沌理论假设系统在替代稳定状态之间发生转变。 对这些相对突然的变化的复杂动态的调查一般都是在重大扰动发生之后进行的，由于其突然性和不可预测性，可用来描述事件发生之前的情况的数据相对较少。 周期性出现的大量蝉是可以预测的，但它们发生的频率不足以构成一个很好的模型，不可预测的干扰事件的灾难性的比例。 这项探索性研究小额赠款将从2002年夏季开始在印第安纳州中部建立一套基线测量，以应对2004年中期的大规模霍乱爆发。 在印第安纳州中部，蝉每17年爆发一次，爆发的规模是美国任何地方发现的最大的。爆发之间的时间间隔是如此之长，以至于蝉有效栖息的森林系统的大多数元素对爆发的形式和特征都没有工作记忆。 在暴发前，地下蝉大量消耗树木根系，而在暴发后，它们可以迅速地使树冠落叶。 它们成为许多物种的猎物，经常导致“捕食者饱和”，因为野生动物狼吞虎咽地吃着似乎无穷无尽的昆虫，这种进食模式可以极大地改变这些捕食者在爆发当年和随后几年的生存和繁殖率。 产卵可导致受影响树木的损坏或死亡，树冠的损失可改变林下的小气候，影响蒸腾速率，进而影响地下水和地表水水文。 为了制定基线信息，据以评估2004年印第安纳州中部暴发的霍乱的影响，这个研究小组将于2002年中期开始进行一系列测量，该小组的成员来自地理、生物、地质以及公共和环境事务部门。 测量的变量包括养分动态、水文、林冠覆盖、树木生理、幼苗建立和社会经济因素。该奖项将有助于建立基线测量，以便在未来几年进行后续研究。 除了为广泛调查自然和人类系统之间的相互作用奠定基础外，该项目还将产生更广泛的积极影响，包括本科生和研究生的参与和培训，以及建立可用于广泛调查的数据库。

Recently developed ecological theories had identified major disturbance events as crucial factors in large-scale environmental change and evolution. Punctuated equilibrium and chaos theories posit shifts in systems between alternative stable states. Inquiries into the complex dynamics of these relatively abrupt shifts generally have taken place after major disturbances have occurred, with relatively little data available to characterize conditions prior to the events because of their suddenness and unpredictability. Periodic emergence of cicadas in massive numbers are predictable, but they occur infrequently enough to constitute an excellent model of unpredictable disturbance events of catastrophic proportions. This Small Grant for Exploratory Research will establish a set of baseline measurements in central Indiana starting in the summer of 2002 in anticipation of a major cicada outbreak in mid-2004. Cicada outbreaks occur every 17 years in central Indiana, where the size of the outbreak is among the largest found anywhere in the U.S. The time period between outbreaks is so long that most elements of the forest system that the cicadas inhabit effectively have no working memory of the form and character of the outbreak. Before the outbreak, cicadas underground are massive consumption of tree root systems, while after the outbreak, they can rapidly defoliate tree canopies. They become prey to a number of species, frequently inducing "predator saturation" as wildlife gorge on the seemingly endless supply of insects, an eating pattern that can dramatically alter the survival and reproduction rates of those predators during the year of the outbreak and in following years. The laying of eggs can lead to damage or death of affected trees, and loss of tree canopy can alter the microclimatology of the understory and affect transpiration rates, which in turn affects groundwater and surface stream hydrology. In order to develop baseline information against which to evaluate the impacts of the 2004 cicada outbreak in central Indiana, this research team, which includes members drawn from geography, biology, geology, and public and environmental affairs departments, will begin taking a series of measurements in mid-2002. Among variables to be measured are nutrient dynamics, hydrology, canopy cover, tree physiology, seedling establishment, and socioeconomic factors.This award will help establish baseline measurements from which follow-up studies can be conducted in the coming years. In addition to laying the groundwork for a broad range of inquiries into interactions between natural and human systems, the project will have positive broader impacts, including the involvement and training of undergraduate and graduate students and the establishment of databases that can be used for a broad range of inquiries.