Conservation PDF - BIO3 Ecosystem Dynamics

CONSERVATION BIO3 – Ecosystem Dynamics Island Biogeography  The study of islands led to the development of the equilibrium model  This model relates to the idea that an equilibrium between organisms is established over time on islands  The model provides the basis for much of the pract...

CONSERVATION BIO3 – Ecosystem Dynamics Island Biogeography  The study of islands led to the development of the equilibrium model  This model relates to the idea that an equilibrium between organisms is established over time on islands  The model provides the basis for much of the practice of modern conservation biology and is particularly relevant for understanding how human development affects an ecosystem  When humans clear habitats for development or build roads they fragment ecosystems, creating what are in essence island environments  By applying the island equilibrium model and other ecological principles to fragmented ecosystems, planners and land managers can attempt to mitigate the effects of habitat loss and aid conservation Conservation and Nature Reserves  Large habitats are better  More resources, niches, nesting sites etc  Some migration can occur  Greater biodiversity  Corridor effect  Joining regions allows for more migration, foraging, dispersal etc  Edge effect  Boundaries are not “walls”, but there is habitat disturbance that extends into the area, particularly in forests  If the forest is more fragmented and has more edges, more of the area will be disturbed Nature Reserves In situ Conservation  In situ conservation involve the species remaining in their natural habitat. Often active management is still necessary such as:  Control of alien/invasive species  Reintroduction of natives species  Limiting predators  Feeding programs  Limiting access Ex situ Conservation  Ex situ conservation involve the removal of species from their natural habitat  This can include:  Botanic gardens  Captive breeding programs  Zoos Example - The Black Footed Ferret  Though black-footed ferrets sometimes eat squirrels, mice, and other rodents, prairie dogs are essential to their survival, making up the majority of the ferret diet. These voracious predators hunt them in their own burrows, and take shelter in abandoned prairie dog dwellings.  Many prairie dog populations underwent a 20th century decline. Farmers and ranchers (with government assistance) eliminated many prairie dogs because their underground complexes are destructive to fields.  In the process, the black-footed ferret was nearly wiped out. In 1987, 18 animals were captured in the wild to begin a captive breeding program, which has since reintroduced ferrets into promising western habitats. Example - The Black Footed Ferret Rewilding  Rewilding is the process of rebuilding ecosystems by restoring natural processes and food webs at all trophic levels as a self-sustaining and resilient ecosystem with biota that would have been present had disturbance not occurred  The ultimate goal of rewilding is the restoration of functioning native ecosystems, containing the full range of species at all trophic levels while reducing human control and pressures  Rewilded ecosystems should – where possible – be self-sustaining, so they require no or minimal management Rewilding Principles  Utilizes wildlife to restore trophic  Requires local engagement and interactions support  Employs landscape-scale planning  Is informed by science, traditional that considers core areas, connectivity, ecological knowledge, and other local and co-existence knowledge  Focuses on the recovery of ecological  Is adaptive and dependent on processes, interactions, and conditions monitoring and feedback based on reference ecosystems  Recognizes the intrinsic value of all  Recognizes that ecosystems are species and ecosystems dynamic and constantly changing  Requires a paradigm shift in the  Should anticipate the effects of coexistence of humans and nature climate change and where possible act as a tool to mitigate impacts Example - Hinewai Reserve New Zealand Sustainability  Human activities rely on the harvesting of resources, such as food and timber, for which we rely on the natural environment  A sustainably harvested resource is one which is replaced as rapidly as it is harvested, meaning that it does not run out  In order for a resource to be sustainable, its use needs to be carefully regulated and monitored to ensure that it is not over-harvested  This can be difficult to achieve, and is not consistently done globally Example – Tree Ferns  Tree ferns (Dicksonia antarctica) are a popular garden and landscaping plant in Australia  They are slow growing (only 3.5 to 5 cm per year) and produces spores at about 20 years  In Australia, wild harvesting requires permits in order to encourage cultivation for selling tree ferns to promote sustainability  Nurseries are also often required to tag their ferns stating if they are wild harvested or nursery grown Example – Marine Fish  The Alaska pollock fishery is the largest sustainably certified fishery in the world  The fishery is considered to be sustainable because:  Pollock are a fast-growing species  Proportion of fish caught that are not pollock (known as bycatch) is very low (less than 1 %)  Any bycatch that is caught cannot be sold commercially, so it is avoided by fishermen  Close monitoring is carried out by science research vessels and by trained individuals  Any areas where a higher than normal number of salmon bycatch occurs are closed off to fishing vessels