2023-02-10 14:06:03
Post from phys.org
Exploring the historical habitats of deciduous oak species, and their current distributions, is an important step for conservationists seeking to protect and restore these important woody plants. Oak species and their numerous relatives, including white, red and black oak in North America and beech, hornbeam and sessile oak in Europe, are critical components of terrestrial ecosystems worldwide, providing food, shelter and habitat for a myriad of species.
In recent years, the range and number of deciduous oak species have declined significantly due to habitat loss and fragmentation, climate change and human-induced fires. To conserve and restore oak species, it is essential to understand their original habitats, the processes by which they have been lost and the overall patterns of their current distribution.
Relying on fossil records and the genetic data of existing oaks, researchers have identified historical refugia, regions in which oaks survived past climate changes, leading to the creation of current extant species. In Europe, oaks initially inhabited the south, and plants were able to move north as the climate warmed during the Holocene epoch, while other species were located in patches in higher elevations and more northern latitudes away from the extreme cold temperatures.
In the western United States, research suggests that the ancestral oak species inhabited the mid-continent region of the United States and parts of Mexico. These oak species were able to move north as the climate cooled during the Pleistocene epoch; however, much of the current distribution of oak species comes from secondary dispersal events due to the creation of new habitats by humans and human-related disturbances, such as fires and grazing.
In addition to identifying refugia and the current distributions of different oak species, researchers examine the ecological shifts associated with changes in climate and land use. This includes analyzing different genetic populations and exploring species migration, ecoregional adaptability and resilience, and other factors that could play a role in species survival and extirpation.
Ultimately, understanding the historical and current distributions of deciduous oak species can be essential in conserving them. Such information can help land managers and conservationists protect the existing remnants and create new population sources, while also addressing the issues of habitat degradation and fragmentation. By doing so, future generations could continue to enjoy the beauty, ecological complexity and cultural importance of oak species around the globe.