A Socio-Ecological Observatory for the Southern African Woodlands

*背景随着气候变化、大气中二氧化碳浓度的增加以及燃料、食物和建筑材料的收获，地球的植被正在发生变化。这些变化可以通过改变碳循环来加速或减少气候变化，还会影响那些在日常生活中使用自然资源的人的生计。要了解植被变化及其影响，最重要的方法之一是反复仔细测量相同的植被斑块(“地块”)。这些地块的网络产生了令人惊讶的发现，挑战了植被对气候变化反应的理论和模型。例如，在拉丁美洲，这些地块的网络表明，热带森林吸收的碳并不像预测的那么多。这些地面地块测量的网络是获得植被目前变化的详细信息的唯一途径。然而，目前，不同的研究人员并没有结合他们的数据来理解地区变化的模式。该项目将通过将收集南部非洲林地地块数据的研究人员聚集在一起来解决这一问题，共享数据并回答有关该地区植被正在发生的重大问题。南部非洲林地是世界上最大的稀树草原(300万平方公里)，支持1.6亿人的生计。这些人中的许多人很穷，他们25%的收入依靠林地为生，以支持他们的农业。理论和模型表明，这些林地将对大气中二氧化碳的增加和正在发生的其他环境变化非常敏感：这是因为，与森林不同，林地在树木和草之间的竞争中保持平衡，允许这两种植物共存。有利于树木的微小变化(例如大气中更多的二氧化碳)可能会迅速将林地转变为以树木为主的系统。这将意味着它们储存了更多的碳，但可能会减少地面植物的多样性。人类对这些林地的利用，特别是采伐木材作为燃料，也有可能改变了它们的多样性，减少了它们提供的“服务”。目前，我们无法知道这些变化是否正在发生--卫星数据和模型可以提供帮助，但需要用地块测量来验证。*目的和目标了解南部非洲林地对全球变化的反应是南部非洲森林委员会的长期目标。它将通过创建一个定期重新衡量的系统情节网络来做到这一点。这个网络的基石是：1)开发一个在线数据共享平台来交换现有的地块数据，这样我们就可以寻找大范围变化的迹象2)将NERC资助的486个地块的数据与其他人测量的1,783个地块的数据结合起来，创建一个覆盖整个地区的网络3)使用这个新的数据集来更好地了解允许树木和草共存的过程，使建模人员能够更好地预测未来的变化4)鼓励研究人员在未来以类似的方式进行测量，以便我们可以更容易地检测到变化5)为未来覆盖整个地区的地块测量制定计划，谁将受益？SEOSAW将填补热带地区地块网络中的一大空白，并从中受益：-地球植被建模人员将能够在最难模拟生物群落之一的地方对照现实测试他们的模型-使用卫星数据绘制植被地图的科学家现在将能够校准和验证他们在所有类型热带植被中的地图-那些建模碳循环的人需要知道林地正在吸收多少碳-自然资源保护者也将受益，因为SEOSAW将识别该地区拥有独特或特别多样化的林地的部分，帮助优先考虑保护工作。

* ContextThe Earth's vegetation is changing in response to climate change, increased concentrations of CO2 in the atmosphere, and harvesting for fuel, food and building materials. These changes can accelerate or reduce climate change by altering the carbon cycle, and also affect the livelihoods of those who use natural resources in their day-to-day lives. One of the most important ways to understand vegetation change and its impacts, is to make careful measurements of the same patches of vegetation ("plots") repeatedly. Networks of these plots have produced surprising findings, challenging theory and models of vegetation responses to climate change. E.g. in Latin America, a network of these plots has shown that tropical forests are not soaking up as much carbon as predicted.Networks of these on-the-ground plot measurements are the only way to get a detailed view of how vegetation is currently changing. However at the moment, different researchers do not combine their data to understand regional patterns of change. This project will address this by bringing together researchers collecting plot data in southern African woodlands to share data and answer the big questions about what is happening to the vegetation in the region.The southern African woodlands are the largest savanna in the world (3 million km2), and support the livelihoods of 160M people. Many of these people are poor and depend upon the woodlands for 25% of their income and to support their agriculture. Theory and models suggest that these woodlands will be sensitive to increased atmospheric CO2 and other environmental changes underway: this is because, unlike forests, woodlands maintain a balance in the competition between trees and grasses, allowing both types of plant to co-exist. Small changes that benefit trees (such as more CO2 in the atmosphere) might rapidly change woodlands into a tree-dominated system. This would mean that they store more carbon, but might reduce the diversity of plants on the ground. It is also possible that human use of these woodlands, particularly wood harvesting for fuel, is altering their diversity and reducing the "services" that they provide. Currently we have no way to know if these changes are happening - satellite data and models can help, but need to be validated with plot measurements. * Aims and objectivesUnderstanding the response of southern African woodlands to global change is the long-term goal of SEOSAW. It will do this by creating a regularly re-measured, systematic plot network. The stepping stones to this network are to:1) develop an online data-sharing platform to exchange existing plot data so that we can look for signs of widespread change2) combine NERC-funded data from 486 plots with data from 1,783 plots measured by others, to create a network that covers the whole region3) use this new data set to better understand the processes that allow trees and grasses to co-exist, to allow modellers to make better predictions of future change4) encourage researchers to make measurements in similar ways in the future, so that we can more easily detect changes5) create a plan for future plot measurements that covers the whole region, and makes best use of the available time and money.* Who will benefit?SEOSAW will fill a large gap in the network of plots in tropical regions and benefit:- modellers of the Earth's vegetation will be able to test their models against reality in one of the most difficult to model biomes- scientists using satellite data to map vegetation will now be able to calibrate and validate their maps in all types of tropical vegetation- Those modelling the carbon cycle, who need to know how much carbon is being taken up by the woodlandsConservationists will also benefit, as SEOSAW will identify parts of the region that have unique or particularly diverse woodlands, helping to prioritise conservation efforts.