DISSERTATION RESEARCH: Microbial Responses to Elevation in a Tropical Montane Cloud Forest

热带山地云雾森林的特点是持续的低层云层覆盖。这些云会改变光线、温度和降水量。它们还支持生活在树枝和树干上的大型植物群落。随着时间的推移，死亡的植物材料收集和分解这些分支，形成？冠层土壤？很少有研究调查冠层土壤中的微生物群落。尽管如此，这一点很重要，因为微生物群落分解植物中的有机物质，并将二氧化碳（一种温室气体）释放到大气中。这一过程主要是在森林地面的土壤中测量的。基于这些森林地面测量，我们估计热带生态系统中的微生物对全球二氧化碳的产生有很大贡献。然而，这些估计并没有考虑到冠层土壤。确定冠层土壤对微生物多样性和碳循环的贡献将使我们能够更好地确定热带生态系统在全球碳循环中的作用。反过来，这些知识将使我们能够更准确地预测这些生态系统如何应对未来的环境变化。此外，国际研究和合作对于促进环境管理和建立具有共同目标的研究人员网络十分重要。该项目涉及与另一位研究人员的多学科合作，将有助于建立一个更强大的国际研究网络，这项研究将把冠层土壤纳入热带山地云雾森林微生物多样性的调查。为了全面评估冠层土壤的多样性以及它们与陆地土壤的比较，研究人员将测量真菌和细菌的多样性。更大的非生物压力在热带树冠应选择不同的微生物群落比陆地土壤中存在。因此，研究人员假设冠层和陆地土壤将拥有不同的微生物群落。此外，由于有机质的增加，冠层土壤中碳靶向酶的胞外酶活性将更高。将在蒙特韦尔德云雾森林保护区内的蒂拉兰山脉的大西洋和太平洋斜坡上沿沿着两个海拔样带收集树冠和陆地土壤。采集将在旱季（1月至4月）和雨季（5月至11月）进行，以探索该生态系统中季节性的差异。将测量真菌和细菌多样性以及胞外酶活性。

Tropical montane cloud forests are characterized by persistent low-level cloud cover. These clouds alter light, temperature, and precipitation. They also support a large community of plants living on the branches and trunks of trees. Over time, dead plant material collects and decomposes on these branches, forming ?canopy soil?. Few studies have investigated the microbial communities within canopy soils. Nevertheless, this is important because microbial communities decompose organic material from plants and release CO2 (a greenhouse gas) into the atmosphere. This process has primarily been measured in soils on the forest floor. Based on these forest floor measurements, we estimate that microbes in tropical ecosystems can contribute greatly to global production of CO2. However, these estimates do not account for canopy soil. Determining how canopy soils contribute to microbial diversity and carbon cycling will allow us to better determine the role of tropical ecosystems in the global carbon cycle. In turn, this knowledge will allow us to make more accurate predictions of how these ecosystems may respond to future changes in the environment. Moreover, international research and collaborations are important to promote environmental stewardship and create networks of researchers with common goals. The project involves a multidisciplinary collaboration with another researcher and will help build a stronger, international research network.This research will incorporate canopy soil into the investigation of microbial diversity in tropical montane cloud forests. To obtain a full assessment of the diversity within canopy soils and how they compare to terrestrial soils, the researchers will measure both fungal and bacterial diversity. Greater abiotic stress within tropical canopies should select for different microbial communities than are present in terrestrial soil. Therefore, the researchers hypothesize that canopy and terrestrial soils will harbor distinct microbial communities. In addition, extracellular enzymatic activity of C-targeting enzymes will be higher in canopy soils due to increased organic matter. Canopy and terrestrial soils will be collected along two elevation transects each on the Atlantic and Pacific slopes of the Cordillera de Tilarán within the Monteverde Cloud Forest Reserve. Collections will occur during the dry (January to April) and wet (May to November) seasons to explore differences in seasonality within this ecosystem. Fungal and bacterial diversity and extracellular enzymatic activity will be measured.