Wetlands, climate change and human disturbance:microscale to macroscale studies

据估计，湿地覆盖了地球陆地表面的4-8%，是湖泊、水库、河流和其他淡水水体的2-3倍。世界上湿地土壤含碳量最大，其中很大一部分在加拿大湿地（包括泥炭地）。人为干扰是威胁加拿大湿地和碳资源以及（直接和间接）依赖湿地的大型经济的主要环境问题。粮食生产、园艺泥炭工业、供水、生态旅游活动、土著社区)。湿地干扰也与气候变化密切相关。不幸的是，很难确定哪些干扰是在自然变率范围内，哪些是由人类造成的。本研究采用古生态学方法（即古生态学方法）。通过对花粉、植物大化石、遗存变形虫、沉积物特征、碳封存、年龄测定等数据的分析，重建长（全新世）和短（100年）的湿地环境，以评估变化的性质和干扰的程度。本研究有助于解决湿地变化的争议，即气候引起的湿地土壤分解是否会对气候变化产生正反馈，或者相反，植物生物量产生的碳是否会超过分解量，从而对气候变化产生负反馈。遗存变形虫是湿地微生物群落的重要组成部分，人们正在研究遗存变形虫作为整个微生物群落的敏感生物监测仪，以识别小尺度气候和碳变化以及人类影响。鉴于湿地是加拿大自然景观的主要组成部分，本项目收集的信息将提供评估负面环境干扰的规程。这些信息将用于制定更好的管理计划、环境和经济政策和条例，以及目前在加拿大地方、省/地区和国家各级进行的湿地恢复和恢复工作。

Wetlands are estimated to cover 4-8% of the land surface of the Earth, which is 2-3 times more than lakes, reservoirs, rivers and other freshwater bodies. The world's wetland soils contain the greatest quantities of carbon, a large proportion of which is in Canadian wetlands (including peatlands). Disturbance by humans is a major environmental problem threatening Canada's wetland and carbon resources and the large economy dependant (directly and indirectly) upon wetlands (ie. food production, horticultural peat industry, water supplies, ecotourism activities, native communities). Wetland disturbances are also closely linked to climate changes. Unfortunately, it is difficult to identify which disturbances are within the natural range of variability and which are due to humans. This research uses paleoecological methods (ie. analysis of pollen, plant macrofossils, testate amoebae, sediment characteristics, C sequestration, age dating) to reconstruct past wetland environments over long (Holocene time) and short (100 years) time frames to assess the nature of change and magnitude of disturbances. This research contributes to resolving controversies about changes in wetlands, whether climate induced soil decomposition in wetlands will have positive feedback to climate change, or conversely, if carbon derived from plant biomass will exceed decomposition, thereby having negative feedback to climate change. Testate amoebae, a large component of wetland microbial communities, are being studied to develop testate amoebae as sensitive biomonitors of whole microbial communities to identify small-scale climate and carbon changes and human impacts. Given that wetlands are a predominant part of the natural landscape in Canada, the information collected in this project will provide protocols for assessing negative environmental disturbances. This information will feed into development of better management plans, environmental and economic policies and regulations, and wetland restoration and rehabilitation efforts currently practiced at local, provincial/territorial, and national levels in Canada.