National-scale assessment of ecological content in the world%26apos;s largest land management framework

作者：Twidwell Dirac^*; Allred Brady W; Fuhlendorf Samuel D

来源：Ecosphere, 2013, 4(8): 94.

DOI：10.1890/ES13-00124.1

• alternative state
• climate change
• community climax
• conservation funding
• ecosystem models
• equilibrium
• historical plant community
• natural resource policy
• rangeland assessment
• succession
• state-and-transition model
• threshold

Meeting the diverse sustainability targets of modern society has led to the development of national-level management frameworks meant to guide resource management actions and conservation funding decisions. In U.S. rangelands, state-and-transition models have been developed within the Ecological Site Description (ESD) Database as an application of alternative state theory and to move the discipline toward a more dynamic platform for resource management. After 15 years of development, and with government-mandated collaboration among federal agencies, these models are set to become one of the world%26apos;s largest guiding frameworks for terrestrial ecosystem management. Yet, ESD state-and-ransition models are being marketed for broad-scale application without a national-level critique evaluating their strengths and limitations. In this article, we conduct a national assessment of ESDs with a central focus on evaluating the specific details of ESD state-and-transition models. Importantly, we are not evaluating the conceptual underpinnings of the state-and-transition management framework, but rather its application. Specifically, we (1) quantify and summarize the information presented in ESD state-and-ransition models; (2) determine whether ESDs fully meet U.S. Congress%26apos;s goal of a nationally consistent system for defining, mapping, and interpreting ecological sites; (3) identify limitations and logical holes in ESD predictions; and (4) evaluate whether conservation funding priorities are consistent with output from ESDs. Our evaluation reveals multiple shortcomings in the application of the state-and-transition model concept within ESDs, primarily that they are highly subjective, inconsistent in design and application, focus on a single historical climax community, and overuse grazing as a driver of both ecological degradation and restoration. Considering that many of these limitations have been a consistent criticism of rangeland assessment procedures throughout the history of the discipline, state-and-transition models within ESDs will require major reconstruction beyond the current plans for revision if they are to meet society%26apos;s demand for more effective management and utilization of rangeland resources. While ESDs were developed to link science and management in rangeland ecology, our assessment suggests well-intentioned management frameworks built upon expert opinion and qualitative inputs will not effectively shift ecosystem management from long-held practices rooted in community climax theory to modern scientific perspectives based on alternative state theory.

• 出版日期2013-8