Impact of planting trees on abandoned farmlands on diversity and carbon sequestration

在废弃农田上建立种植园为将碳隔离到植物生物量和土壤中提供了很好的机会。与耕地相比，在废弃农田上建立种植园可以加快本土植物的入侵和安装，从而有利于生物多样性，因为在这些地方，植物演替的生态障碍可以阻止或减缓殖民。然而，种植园履行其所取代的生态系统(休耕土地、耕地或森林)中通常存在的生态服务的潜力在很大程度上是未知的。本研究旨在确定建立杨树和云杉杂交林对维管和非维管植物功能多样性和物种组成、土壤微生物群落和碳含量的影响，并与以前利用这些地点以及与周围森林和未种植的废弃农田进行比较。我们还打算沿着种植(白云杉)和可比的未种植休耕地的时间序列来比较生物多样性。最后，本研究旨在确定增加深层土壤固碳和稳定形态的功能根系特征，以及土壤微生物群如何与这些特征相互作用。已建立的白云杉和杂交杨树人工林将根据以前的土地利用(杨树)和树龄(云杉)作为样本，以比较未种植的废弃农田和周围森林的植物组成和土壤微生物群特征。将在杂交杨树人工林中测量土壤碳以及几个生长速度较慢到较快的无性系的根系功能性状，以便将这些性状与长期固碳联系起来。最终，该项目将有助于根据生态标准做出明智的决策和对种植园的营林投资，并优化结果，更好地针对加拿大利用树木补偿二氧化碳排放和管理景观多样性的目标。

The establishment of plantations on abandoned farmland offers good opportunities to sequester carbon into plant biomass and soils. Plantations established on abandoned farmlands can be beneficial to biodiversity compared to cultivated lands, by accelerating the invasion and installation of native plants where ecological barriers to plant succession can halt or slow down colonisation. The potential for plantations to fulfill ecological services typically found in the ecosystems they are replacing (fallow lands, cultivated lands or forests) is however largely unknown. This study aims to determine the effects of establishing hybrid poplar and white spruce plantations on vascular and non-vascular plant functional diversity and species composition, soil microbiome and carbon content, in relation to the previous use of the sites and in comparison with surrounding forests and unplanted abandoned farmlands. We also aim to compare biodiversity along a chronosequence of planted (white spruce) and comparable unplanted fallow lands. Finally, this study aims to identify functional root traits that increase carbon sequestration in deep soil layers and in stable forms, and how the soil microbiome interacts with these traits.Already established white spruce and hybrid poplar plantations will be samples according to their previous land use (poplar) and age (spruce), in order to characterize their plant composition and soil microbiome, in comparison with unplanted abandoned farmland and surrounding forest. Soil carbon will be measured in the hybrid poplar plantations along with root functional traits of several clones that have slow to rapid growth rates, in order to link these traits with long term carbon sequestration. In the end, this project will contribute to make informed decisions and silviculture investments into plantations, according to ecological criteria and optimize outcomes better targeted to Canada's objectives of using trees to compensate CO2 emissions and manage diversity over the landscape.