To assess the effects of global change on peatland vegetation and biogeochemistry we used a long term (21 years) in-situ plot scale manipulation experiment comprising nitrogen (N; ambient and 30 kg ha⁻¹ yr⁻¹), temperature (T; ambient and + 3.6 °C during growing season) and sulfur (S; ambient and 20 kg ha⁻¹ yr⁻¹) treatments in an oligotrophic boreal peatland. Vegetation was assessed by plant species cover estimates, while biogeochemical processes were characterized by measuring potential extracellular enzyme activity (EEA) of glucosidase, cellulase, aminopeptidase, phosphatase, and sulfatase in the peat matrix. We hypothesized that the plant communities would change in response to the N and T manipulations, and that belowground EEA would respond distinctively to the applied treatments as well as to changes in plant community. We found vascular plant cover to have strongly increased in the T treatment, whereas the Sphagnum cover collapsed in the high N treatment. Belowground we found enhanced enzymatic C and N acquisition activity in response to the N treatment, but EEA showed no response to the T treatment. No S effects were found, neither aboveground nor belowground. Contrary to our expectations, our data reveal a mismatch between above-ground vegetation patterns and belowground decomposition processes. In particular, the large increase in vascular plant cover in the warming treatment found no reflection in belowground EEA.

为了评估全球变化对泥炭地植被和生物地球化学的影响，我们使用了一项长期（21年）原位样地规模操作实验，包括氮（N；环境和30 kg ha ^-1  yr ^-1），温度（T；环境）和+ 3.6°C在生长季节）和硫（S；环境和20 kg ha ^-1  yr ^-1）在贫营养的北方泥炭地进行治疗。通过植物物种覆盖率评估来评估植被，同时通过测量泥炭基质中葡萄糖苷酶，纤维素酶，氨肽酶，磷酸酶和硫酸酯酶的潜在细胞外酶活性（EEA）来表征生物地球化学过程。我们假设植物群落会因氮和氮的操纵而发生变化，而地下EEA将对所应用的处理方法以及植物群落的变化做出独特的响应。我们发现在T处理中维管植物的覆盖率大大增加，而泥炭藓高氮处理下覆盖层塌陷。在地下，我们发现响应N处理增强了酶C和N的采集活性，但EEA没有显示出对T处理的响应。地面和地下都没有发现S效应。与我们的预期相反，我们的数据揭示了地上植被模式与地下分解过程之间的不匹配。特别是，在升温处理中维管植物的大量增加没有发现地下EEA的反射。