"Nordeste"

与该国其他地区相比，巴西东北部地区相对干燥，降雨模式异常不规则，伴随着频繁的干旱。那里的土壤往往相对肥沃，因此，尽管作物歉收有时发生在干旱的年份，但该地区人口相当密集，约占巴西人口的15%；但条件通常是贫困的。这导致了对自然植被的极端土地利用压力和剩余土地的广泛退化。与世界上其他土壤和气候相似的地区一样，该地区的自然植被是一种落叶灌木，在当地被称为Caatinga。可能是因为卡廷加缺乏潮湿的热带森林的复杂性和宏伟壮观，这种植被类型在很大程度上被忽视了，无论是在保护计划还是科学研究方面。鉴于卡丁加的巨大破坏，这种忽视产生了严重的后果，其破坏程度超过了亚马逊和塞拉多附近的生物群。由于它们对巴西未来更温暖和更干燥的气候具有潜在的重要性，保护适应高温和季节性反复无常的降雨的卡丁加植物物种至关重要。作为一项涉及巴西和英国研究人员的综合研究计划，“Nordeste”将试图纠正这一疏忽：1.通过建立一个类似于潮湿热带森林中现有的永久地块网络，首次评估卡廷加树冠结构和动态及其短期和长期气候变化反应的测量。借助新的DNA条形码测量，旨在更好地量化该区域的生物多样性。通过对自然和受干扰的生态系统的生物地球化学进行全面分析，了解养分循环过程如何因土壤、气候和人类活动的变化而变化4。通过对该地区发现的各种不同Caatinga亚型进行一系列详细的结构和生理测量。这些将在该地区的地上和地下以及自然和退化的生态系统中进行。将特别强调旨在帮助我们理解为什么在某些情况下，尽管降雨量很低，卡廷加的生物量却很高的测量方法。5.还将进行温室实验，比较湿润森林、稀树草原和卡廷加原生苗木的水分胁迫反应，以尝试并了解植物对频繁和/或不稳定的极端土壤缺水条件的适应涉及哪些特定的代谢适应。通过一个综合模拟程序为半辅助生态系统提供新的地表通量参数，并为木本植物地上部的变化提供新的见解：根分配模式对降水条件变化的响应。为了实现这些目标，该项目被设计为一系列六个相互关联的基于野外的工作程序包，第七个工作程序包专注于物种分布、生态系统通量的模拟，并从机理上理解卡廷加植被对气候和土壤性质变化的功能反应。这项研究还旨在制作一系列定义明确的产品，以帮助决策者和当地社区更好地管理这一独特的资源--例如，对具有生态优势和经济用途的植物的在线指南，这项研究将有助于为更好地了解卡廷加植被及其对人为和土地利用变化压力的反应迈出宝贵的第一步。

The northeast region of Brazil is relatively dry compared to the rest of the country, with unusually irregular rainfall patterns and associated frequent droughts. The soils there tend to be relatively fertile and so, despite crop failures sometimes occurring in drier years, the area is reasonably densely populated with about 15% of Brazil's population living there; but under what are generally impoverished conditions. This has led to extreme land-use pressures on the natural vegetation and widespread degradation of remaining lands.As in other parts of the world with similar soils and climate, the natural vegetation of the area is a form of deciduous scrub, known locally as Caatinga. Probably because Caatinga typically lacks the complexity and grandeur of moist tropical forests, this vegetation type has been to a large extent neglected to date both in terms of conservation programmes and scientific enquiry. This neglect has serious consequences given the enormous destruction of the Caatinga, which exceeds that of the neighbouring biomes of Amazonia and the Cerrado. Because of their potential importance in future warmer and drier climates in Brazil, conservation of the plant species of the Caatinga, which are adapted to high temperatures and seasonally erratic rainfall, is vital. Designed as an integrated research program involving both Brazilian and UK researchers 'Nordeste' will attempt to redress this neglect:1. Through the establishment of a permanent plot network similar to that existing in moist tropical forests, allowing measurements of Caatinga canopy structure and dynamics and both their short- and long-term responses to climate change to be evaluated for the first time.2. With the aid of new DNA barcoding measurements designed to better quantify the biodiversity of the region.3. Through a comprehensive analysis of the biogeochemistry of natural and disturbed ecosystems to develop an understanding of how nutrient cycling processes vary in response to variations in soils and climate and human activity4. Via a series of detailed structural, physiological measurements across the wide range of different Caatinga sub-types found in the region. These will be made both above- and below-ground and in natural and degraded ecosystems of the region. A special emphasis will be placed on measurements designed to help us understand why it is that under certain circumstances it is that very high biomass stands of Caatinga occur despite the very low rainfall. 5. Glasshouse experiments comparing water stress responses of seedlings native to moist forest, savanna and caatinga will also be undertaken in order to try and understand what specific metabolic adaptions are involved in plant adaptions to frequent and/or erratic conditions of extreme soil water deficit.6. Via an integrated modelling program to provide new parameterisations of surface fluxes for semi-aid ecosystems in general and to provide new insights into variations in woody plant shoot: root allocation patterns in response to variation in precipitation regime.To achieve these aims, the project has been designed as a series of six inter-related field-based workpackages, with a seventh workpackage focussed on modelling of species distributions, ecosystem fluxes and developing a mechanistic understanding of caatinga vegetation functional responses to both variations in climate and soil properties. Designed with a view to also producing a series of well-defined products to assist both policy makers and local communities to better manage this unique resource - for example, online guides to ecologically dominant and economically useful plants, the study will serve to provide a valuable first step towards a better understanding of Caatinga vegetation and its responses to anthropogenic and land-use change pressures.