The landscape can be seen as a mosaic of interrelated and interdependent systems, a series of habitat patches and corridors that provide spaces for both wildlife and humans to function and survive. This mosaic is part of what we use in landscape ecology, the interdisciplinary study of spatial patterns and processes in the landscape. It is easiest to grasp these patterns and imagine habitat potential and connections when one can see them broadly, from the window seat of an airplane, for instance. This opportunity came as I returned this April from “Examining Sustainability in Dynamic Landscapes,” the International Association of Landscape Ecology’s annual symposium in Portland, Oregon…
As the plane lifts off the runway, Portland’s fir trees and small houses give way to patches of residential hamlets nestled in dark hills. Once we hit cruising altitude the mountains appear, never ceasing to take my breath away with their powdery white peaks. Further on, agricultural fields come into view, the most familiar to me and yet the most alien, as they are the part of the landscape that seems to have been altered the most. Perfect irrigation circles centered in perfect squares-quilted swaths of industrial agriculture. As we get closer to the Midwest, our midway point on this flight home to Baltimore, the patterns change slightly. The irrigation circles are gone but the broad swaths of farms remain.
While the farms are still squares and rectangles in the landscape, darkly colored, sinuous lines appear.
These streams and rivers are often lined with trees, irregularly shaped buffers that cut across the farm land and break the monotony. At some points, small woodland patches appear as dark blotches, while at others the streams skirt the farmland, teasing a curve out of the right angles. If the light is just right, I can pick out the older patterns from water that has been drained from the land, the dark splotches and lines of ancient streams, wetlands, prairie potholes, and fens-shadows of the former hydrology.
My mind drifts back to the symposium. What was unique about this year’s meeting was that while there was still a lot of attention on the study of the patterns and processes of forest and other terrestrial habitat patches, there was more focus on rivers and streams as important corridors and habitat locations. There was a much greater emphasis on the practical application of such research in planning and design for future resilient landscapes. Water was described as both a resource and a critical element in the landscape mosaic. Highlights included talks by researchers examining hydrologic systems as elements in landscape ecology. Lee Benda from the Earth Systems Institute presented work on river catchment connectivity as the context for regional restoration projects along the Pas River in Spain while Peter Kiffney from the Northwest Fisheries Science Center and Hedmark University College presented research on the importance of tributary confluences as habitat connections for salmon in the Pacific Northwest. Stormwater management and riparian habitat function were highlighted in a study being conducted in Vancouver, Washington and Portland, Oregon which links green infrastructure planning work at the site scale with larger habitat function and community resilience.
As I make the connection between these talks and the view from my window seat, I sense, more than ever, the importance of ecological restoration and conservation of functional hydrologic systems in the effort to regenerate and sustain the natural landscape mosaic that underlies our communities, both natural and human-dominated.
To help illustrate the water resource challenges we face in planning for resilience and regeneration, Jennifer assembled a “Water Index” of facts and figures, based on information she culled from various conservation web sites.
A Water Index
The ancient Romans had better water quality than half of the people alive now. (http://water.org)
Less than 1% of the world’s fresh water (or about 0.007% of all water on earth) is readily accessible for direct human use. (World Health Organization Fact Sheet Health in Water Resources Development.)
By 2025, 52 countries-with two-thirds of the world’s population-will likely have water shortages. (http://www.rivers.gov/waterfacts.html)
A 1982 study showed that areas cleared of riparian vegetation in the Midwest had erosion rates of 15 to 60 tons per year. (http://www.rivers.gov/waterfacts.html)
An American taking a five-minute shower uses more water than a typical person in a developing country slum uses in a whole day. (2006 United Nations Human Development Report.)
Only 62% of the world’s population has access to improved sanitation – defined as a sanitation facility that ensures hygienic separation of human excreta from human contact. (UNICEF/WHO. 2008. Progress on Drinking Water and Sanitation: Special Focus on Sanitation.)
The United States consumes water at twice the rate of other industrialized nations. 1.2 Billion – Number of people worldwide who do not have access to clean water. 6.8 Billion – Gallons of water Americans flush down their toilets every day.(http://www.rivers.gov/waterfacts.html)
More than 80% of sewage in developing countries is discharged untreated, polluting rivers, lakes and coastal areas. (2004, Wastewater Use in Irrigated Agriculture- http://water.org)
The average single-family home uses 80 gallons of water per person each day in the winter and 120 gallons in the summer. Showering, bathing and using the toilet account for about two-thirds of the average family’s water usage. (http://www.rivers.gov/waterfacts.html)
At home the average American uses between 100 and 175 gallons of water a day. That is less than 25 years ago, but it does not include the amount of water used to feed and clothe us. (http://water.org)
Agriculture is the largest consumer of freshwater by far: about 70% of all freshwater withdrawals go to irrigated agriculture.(United Nations World Water Development Report, “Water in a Changing World”)
Only 7% of the country’s landscape is in a riparian zone, only 2% of which still supports riparian vegetation. (http://www.rivers.gov/waterfacts.html)
The U.S. Fish and Wildlife Service estimate that 70% of the riparian habitat nationwide has been lost or altered. (http://www.rivers.gov/waterfacts.html)
More than 247 million acres of U.S. wetlands have been filled, dredged or channelized-an area greater than the size of California, Nevada and Oregon combined. (http://www.rivers.gov/waterfacts.html)
Riparian areas in the West provide habitat for more species of birds than all other western vegetation combined; 80% of neotropical migrant species (mostly songbirds) depend on riparian areas for nesting or migration. (http://www.rivers.gov/waterfacts.html)
Fully 80% of all vertebrate wildlife in the Southwest depend on riparian areas for at least half of their life. (http://www.rivers.gov/waterfacts.html)
Of the 1200 species listed as threatened or endangered, 50% depend on rivers and streams. (http://www.rivers.gov/waterfacts.html)
One fifth of the world’s freshwater fish-2,000 of 10,000 species identified-are endangered, vulnerable, or extinct. In North America, the continent most studied, 67% of all mussels, 51% of crayfish, 40% of amphibians, 37% of fish, and 75% of freshwater mollusks are rare, imperiled, or already gone. (http://www.rivers.gov/waterfacts.html)
At least 123 freshwater species became extinct during the 20th century. These include 79 invertebrates, 40 fishes, and 4 amphibians. (There may well have been other species that were never identified.) (http://www.rivers.gov/waterfacts.html)
Freshwater animals are disappearing five times faster than land animals.(http://www.rivers.gov/waterfacts.html)
In the Pacific Northwest, over 100 stocks and subspecies of salmon and trout have gone extinct and another 200 are at risk due to a host of factors, including dams and the loss of riparian habitat. (http://www.rivers.gov/waterfacts.html)
One mature tree in a riparian area can filter as much as 200 pounds of nitrates runoff per year. (http://www.rivers.gov/waterfacts.html)