Chapter 23 Summary

CONCEPT 23.1 Landscape ecology examines spatial patterns and their relationship to ecological processes and changes.

• A landscape is a heterogeneous area of land made up of a dynamic mosaic of different components that interact through the exchange of materials, energy, and organisms.
• Landscapes are characterized by their composition—the elements that constitute them—as well as by their structure—how those elements are arranged on the landscape.
• Landscape patterns regulate ecological processes by determining how easily organisms can move among elements as well as by regulating biogeochemical cycling.
• Landscape patterns both shape and are shaped by disturbances.

CONCEPT 23.2 Habitat fragmentation decreases habitat area, isolates populations, and alters conditions at habitat edges.

• Habitat fragments are generally biologically impoverished compared with the intact habitat from which they were derived.
• Once a habitat fragment is isolated from surrounding habitat, organisms reliant on that habitat may be isolated or may be able to cross the intervening matrix to some extent.
• The edges of habitat fragments have a different abiotic environment and different demographic dynamics than interior habitats.
• The isolation of populations and the shifts in ecological communities that result from habitat fragmentation alter the evolutionary process.

CONCEPT 23.3 Biodiversity can best be sustained by large reserves connected across the landscape and buffered from areas of intense human use.

• The ideal spatial configuration for a core natural area is large, compact, and connected to or close to other protected natural areas.
• Core natural areas should be surrounded by buffer zones predominated by uses that are compatible with biodiversity conservation but which still allow human economic uses.
• Habitat corridors are instrumental in facilitating the movement of organisms between natural areas.
• Ecological restoration allows areas that have been degraded in the past to support native species and ecosystem processes once again.

CONCEPT 23.4 Ecosystem management is a collaborative process with the maintenance of long-term ecological integrity as its core value.

• Collaboration among all stakeholders is key to arriving at effective management plans.
• Ecosystem management is a process of setting sustainable goals, developing and implementing land use management policies, monitoring the effectiveness of prior decisions, and adapting plans accordingly.
• Humans are an integral part of ecosystems, and conservation plans that include the economic and social well-being of local human populations are more likely to succeed over the long term.