Aquatic and terrestrial insect activity phenology with trap collections at the Andrews Experimental Forest, 2009-2014

This study was designed to evaluate the influence of microclimatic heterogeneity, associated with complex terrain, on phenology and to evaluate potential trophic responses to scenarios of climate change, disturbance and land use. We focus on a simplified model trophic system involving vascular plants, terrestrial and aquatic insects, and migratory neotropical and resident birds. The model trophic system is interesting because the phenologies of different components in the model system are independent (cued by various abiotic drivers) and dependent (due to trophic interactions), potentially leading to complex system behaviors. Plant and poiklothermic animal (ex. invertebrates) phenologies are highly temperature dependent. Phenologies of terrestrial plants and invertebrates would therefore likely exhibit wide spatial and temporal variation across the landscape in response to temperature variation associated with elevational differences, cold air drainages patterns, and temperature inversions. Aquatic invertebrate phenologies are also tied to temperature, but stream temperatures are influenced by different factors than those driving air temperatures and they may be less sensitive to complex terrain. For the invertebrate part of this study, we are examining spring-time (April through June) flying (terrestrial and adult aquatic) insect activity and adult aquatic insect emergence across a range of sites in the HJ Andrews Experimental Forest. Flying insect activity will be assessed using malaise traps deployed at 16 sites ranging from 450m to over 1300m in elevation, and with a variety of forest stand ages and slope aspects. Emerging aquatic insects will be collected with emergence traps in six 1st to 2nd order streams ranging from 450m to 1000m in elevation, and differing in water source (spring vs run-off) and surrounding forest age. Insects from malaise traps will be identified to varying levels from order to genus, depending on the group and available keys. Adult aquatic insects will be identified to varying levels from subfamily to species. We will be monitoring overall activity levels and emergence rates over time as well as the activity/emergence of selected key taxa. Data collection began in 2009 and is ongoing.

本研究旨在评估与复杂地形相关的微气候异质性对物候的影响，并评估生态系统对气候变化、干扰及土地利用情景的潜在营养级响应。我们聚焦于一个简化的模式营养系统，涵盖维管植物（vascular plants）、陆生与水生昆虫，以及新热带迁徙鸟类与留鸟。该模式营养系统具有特殊研究价值，因其内各组分的物候既相互独立（由各类非生物因子驱动）又彼此关联（源于营养级相互作用），可能催生复杂的系统行为。植物与变温动物（例如无脊椎动物（invertebrates））的物候高度依赖温度，因此陆生植物与无脊椎动物的物候，会随海拔差异、冷空气下泄模式及气温逆温带来的温度变化，在研究区域内呈现显著的空间与时间异质性。水生无脊椎动物的物候同样与温度相关，但溪流温度的影响因子与驱动气温变化的因子存在差异，且其对复杂地形的敏感性可能更低。针对本研究的无脊椎动物部分，我们将在HJ Andrews实验森林（HJ Andrews Experimental Forest）的多个样地中，调查春季（4月至6月）飞行性（陆生及成虫期水生）昆虫的活动情况，以及成虫水生昆虫的羽化动态。飞行昆虫活动监测将采用马氏诱捕器（malaise trap），布设点位共16个，海拔跨度为450米至1300米以上，同时涵盖不同林分年龄与坡向的样地。成虫水生昆虫羽化量将采用羽化诱捕器（emergence trap），在6条1-2级溪流中采集，这些溪流海拔范围为450米至1000米，水源类型（泉水 vs 径流）及周边林分年龄均存在差异。拦虫网采集的昆虫将根据类群与可用检索表，鉴定至从目到属的不同分类阶元；成虫水生昆虫则将鉴定至从亚科到种的不同分类阶元。我们将同时监测整体活动水平与羽化速率的时间动态，以及选定关键类群的活动/羽化情况。本研究的数据采集工作始于2009年，目前仍在持续进行中。