The State of Forest Genetic Diversity: Anthropogenic Impacts and Conservation Initiatives

Artikel aus einem Buch

18580BU

200212627

Genetic diversity is a key pillar of biodiversity, underlying the adaptive potential of any species. At the same time, it is difficult to quantify this component of biodiversity, and we know very little about the genetic diversity status of most species. A wealth of studies points toward a substantial decline, which is also apparent in numerous forest species. Connectivity is fundamental to maintaining high levels of genetic diversity and adaptability via gene flow between populations. In this chapter, we attempt to elucidate the importance of genetic diversity for the entire forest ecosystem with a focus on its main components: tree species. We elaborate on the anthropogenic factors impacting forest diversity, like exploitation and artificial regeneration, climate change, and introduced pests. An overview of molecular methods for studying genetic diversity and connectivity is presented. Regular genetic monitoring is imperative for optimizing conservation strategies such as the creation of stepping stones to counteract population fragmentation. We highlight the importance of taking genetic diversity into account when sourcing plant material for forest and landscape restoration projects. Finally, international efforts to conserve genetic diversity are presented along with recommendations on suitable indicators to monitor it. Scientists working on genetic diversity are encouraged to actively participate in national and international processes to incorporate genetic principles into policy development as well as conservation and restoration efforts.The concept of landscape connectivity involves species movement between habitat patches influenced by landscape features. It encompasses structural and functional connectivity as well as species-specific considerations. Structural connectivity analyzes spatial patterns of landscapes, while functional connectivity considers the response of organisms to the landscape. Evaluating habitats for connectivity requires accounting for their spatial and temporal variations. Temporal connectivity—often overlooked—is particularly essential for long-term population viability. Conservation planning should therefore integrate monitoring and assessment measures to achieve connectivity objectives in dynamic landscapes affected by land use and climate change. Measuring landscape connectivity considers landscape composition, structure, and heterogeneity as well as the presence of barriers, each varying among species and scales. Assessing connectivity across scales requires considering biological levels of organization from genetic flow to community processes. Modeling connectivity is complex and incorporates patch- and landscape-based approaches. Patch-based models focus on attributes of habitat patches, while landscape-based models consider movement behavior and resistance surfaces. Landscape connectivity research has expanded rapidly in recent decades, and its conceptual foundations are evolving. Recent advances integrate metapopulation dynamics with habitat configuration and movement behavior. Traditional static models are being replaced with dynamic models considering temporal variations in landscape attributes. Further technological advancements such as remote sensing and climate simulators allow more accurate representations of dynamic landscapes, promoting ecosystem understanding and supporting conservation planning.