Wilderness conservation in the Anthropocene

Abstract

Humanity is exerting unprecedented pressure on the natural environment, threatening tensof thousands of species with extinction, and degrading the condition of ecosystemsworldwide. The extraordinary value of the last ecologically intact landscapes, free fromindustrial level degradation (which I call wilderness), is becoming increasingly recognised(chapter 1). Wilderness areas support many of the evolutionary and ecological processesthat underpin all life on Earth, are critical for biodiversity conservation, and support thecultural integrity of many indigenous communities. The overarching aim of this thesis is toaddress key questions relevant to conserving wilderness areas and their values, with a focuson biodiversity conservation.Despite the exceptional value of wilderness areas, information on their location, condition,and threat status globally has been limited. In chapter 2, I utilise a high-resolution (1km2)global dataset of human pressure on the terrestrial environment for the years 1993-2009(appendix 1) to develop the first temporally inter-comparable global maps of terrestrialwilderness areas. I define wilderness as places free from human pressures such as landclearing, dense human settlements, agriculture, and infrastructure developments, whichsignificantly damage the environment. A spatial analysis of changes in wilderness extentbetween 1993 and 2009 showed catastrophic declines amounting to 3.3 million km2, withthe greatest losses occurring in the Amazon and Central Africa (appendix 2). Only 30 millionkm2 of wilderness remains (23% of terrestrial areas).Considering rates and extent of wilderness loss varies throughout the world, it is importantto identify where this loss is impacting species. In chapter 3, I present a global analysis ofcumulative human impacts on threatened species. I develop a novel spatial framework thatjointly considers the co-occurrence of threats and the distribution of 5,457 vertebrates. Idiscover that human impacts extend across 84% of Earth’s terrestrial surface, and identify‘hotspots’ of impacted species richness. One quarter (n=1237) of species are impacted bythreats across >90% of their distribution, and 395 species are impacted across their entirerange. The methodology represents a conceptual advance for analysing threats tobiodiversity, moving beyond analysing human pressures, which are agnostic to species typeand their individual sensitivities to threats, to analysing realised impacts on individualspecies.It is also important to analyse human impacts on the places set aside to protect biodiversity.In chapter 4, I present the first quantitative global assessment of the ecological condition ofNatural World Heritage Sites (WHS), the world’s flagship protected areas. I analyze changesin human pressure and forest loss within WHS, finding that many are more threatened thanpreviously thought. Human pressures and forest loss occur in the vast majority of WHS,causing significant damage to the integrity of some sites. The results provide information tosupport the ongoing preservation of WHS to ensure they maintain their ecological integrity.The approach presents a transparent, defensible method for monitoring the ecological stateof conservation areas.Chapters 3, 4 and Appendix 2 highlighted that wilderness areas are declining and under-protected from the threats they face. They are also not recognised in any major internationalenvironmental agreements. Recognising the need for an international policy mechanismdedicated to wilderness conservation; in chapter 5, I argue that the World HeritageConvention could fill this gap. I assess wilderness coverage within WHS globally, andidentify biogeographic regions without coverage (‘gaps’). I then identify large, nationallydesignated protected areas with good wilderness coverage within gaps, which couldpotentially become new WHS. The results demonstrate that the Convention could make asubstantial contribution to wilderness conservation by designating new wilderness WHS,and by protecting the wilderness condition of existing WHS.The global analysis in chapter 5 highlights the need for regional analyses that align with thescale of conservation action. In chapter 6, I present a regional case study where I analyzepatterns of forest loss in an African wilderness area: Niassa National Reserve inMozambique, where considerable effort and funding is going to conserving forest habitatand wildlife. I show that Niassa’s forest loss is substantially lower than loss in thesurrounding region, suggesting it is performing well at limiting forest loss relative to externalpressure. The majority of Niassa’s habitat is intact, and could support large mega-faunalassemblages. Its outstanding wilderness value could make it a good candidate for WorldHeritage Status.This thesis highlights that our window of opportunity to safeguard wilderness areas and theirvalues for people and nature is closing fast. I provide crucial information on the location,threat, and protection status of terrestrial wilderness areas globally and identify important places for species persistence, providing useful information to guide future conservationagendas at national and global scales.