"Awareness of ecological relationships is – or should be – the basis of modern conservation programs, for it is useless to attempt to preserve a living species unless the kind of land or water it requires is also preserved. So delicately interwoven are the relationships that when we disturb one thread of the community fabric we alter it all – perhaps almost imperceptibly, perhaps so drastically that destruction follows."
- Rachel Carson, Writer, Scientist and Ecologist. 1958 -
Nature Needs Connected Space
Imagine if you were suddenly limited to only move and live within your home and you had to secure all the resources you needed for survival in that space? Could you survive and, if so, for how long?
That is the fundamental ecological crisis facing wildlife in our backyards and across the globe today, as their habitats are reduced into smaller and smaller pieces by human development.
Habitat loss, fragmentation, and geographical isolation create barriers to movement, survival and reproduction. Decades of scientific research tell us that loss of habitats and connectivity are leading to cascading environmental effects; degraded habitats, species extinctions, and reduced biodiversity on both local and global scales.
Scientists tell us plant and animal population size is the best predictor of whether a species or local population will persist. There are scientifically derived minimum viable population numbers at which extinction becomes likely. The amount and quality of habitat available directly influences animal population size. Connectivity of habitat (that meets survival and reproductive needs) and connectivity of subpopulations ensures that animal and plant communities can move and adapt to constant change over short and long time scales. If habitat is reduced to small isolated patches, eventually some species may cease to exist in those areas. Often the first to go are the large ranging mammals that require larger amounts of core habitat such as mule deer and mountain lion, or habitat specialists such as the Sonoran Desert tortoise.
Ecosystems
In an unaltered natural landscape, wildlife populations are constantly moving to seek food, water, shelter and mates. Individual animals move between population groups exchanging genetics in the process. Plant communities thrive through the processes of seed dispersal, pollination, and propagation aided by animals, wind and water. Nature thrives because of complex interactions between living organisms (plants, animals and micro-organisms), their physical environments (soil, rock, minerals, water, and air) and the natural cycling of nutrients, energy and water.
Collectively this living and nonliving complex is the very definition of an ecosystem. Ecosystems are essentially a human construct to define our world; small and large; and can be defined spatially such as a small desert wash, or ecologically such as the Sonoran Desert. The White Tank Mountains are an ecosystem. In any ecosystem, living organisms are constantly adapting to changing environmental conditions; climate patterns, natural disturbances (fires, floods and drought), rates of predation, interactions between species and disease. There is constant competition for food, water, space and mates. Species move physically between subpopulations and genetically through reproduction. Reproduction and mortality are constantly in play, and the rates determine whether a population can grow enough to keep up with natural mortality, changing environmental conditions or sudden natural disturbances in any given area.
Connectivity and Corridors
Corridors (also referred to as Linkages) have become the conservation tool that keeps natural systems and crucial habitats interconnected.
Corridors allow:
- Individual movement to seek survival resources (food, water, cover, mates)
- Dispersal of individuals between subpopulations – gene flow and reduced inbreeding within local populations
- Species to re-colonize suitable habitats
- Seasonal migrations in landscapes where they occur
- Population movement and resilience in response to changing climate, natural disturbances and invasive species
- Maintenance of ecological processes that maintain plant communities such as seed dispersal and pollination; and the flow of nutrients, energy and water
What we know about nature is that given a chance, it will thrive. The conservation of wildlife corridors is about giving nature a chance to thrive by keeping natural systems interconnected, protecting biodiversity, and conserving ecosystem services that humans depend on at local, regional and global scales.
