Biodiversity managers face a dilemma of choosing between “coarse‐filter” approaches that deal with the habitats of several species and “fine‐filter” approaches that address population viability of one or a few species. We present an approach for local spatial scales that integrates habitat‐based and population‐based methods to focus research and management on the species in a community that are most at risk of extinction and on the places in the landscape most important to these species. The steps in Dynamic Habitat and Population (DHP) Analysis are: 1) determine which species in the planning area most merit field study based on existing data; 2) use local field data to select species that most merit demographic study; 3) use demographic data to model population viability of the species deemed most at risk; 4) design and evaluate alternative management strategies for key species and landscape settings. We review each step and provide an example for land birds in a portion of the Greater Yellowstone Ecosystem. Among the 143 species of land birds likely in the study area, we selected 13 species most at risk of extinction. These were mostly neotropical migrant passerines that specialized on low‐elevation deciduous habitats that may serve as population source areas. We present a management plan for the multiple ownerships of the study area that seeks to maintain/restore population source habitats for key species. DHP Analysis provides a framework for biodiversity management for those regions identified as high priority for conservation by continental‐scale assessment programs such as Gap Analysis. Our approach is designed to minimize local extinctions, which should reduce the risk of range‐wide extinctions.

Lake Modre is a lobelia lake. Numerous typical plant species occur here, including Lobelia dortmanna, Littorella uniflora, Isoetes lacustris, and Sphagnum denticulatum. They develop the following associations: Lobelietum dortmannae (Oswald 1923) Tx. ap. Dierss. 1972, Isoetetum lacustris Szańkowski et Kłosowski 1996 n.n., and a community with Sphagnum denticulatum Brid.In 1991, the water of the lake was characterised by low concentrations of nutrients and calcium, acid reaction (pH<5), and Secchi depth visibility of 12 m. Following fry stocking in the lake in 1993 fish farming took place until approximately 1996. During this period the water quality in the lake changed radically in physiochemical terms. Water transparency decreased. Thermal and oxygen stratification developed, with oxygen deficits in the near-bottom layer. Concentrations of nutrient elements increased.Drastic long-term changes were observed in the spatial and quantitative features of the lake vegetation. These particularly related to the instability of Lobelia dortmanna, and the diminishment of the phytocoenosis of Lobelietum dortmannae.

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Biodiversity managers face a dilemma of choosing between ''coarse-filter'' approaches that deal with the habitats of several species and ''fine-filter'' approaches that address population viability of one or a few species. We present an approach for local spatial scales that integrates habitat-based and population-based methods to focus research and management on the species in a community that are most at risk of extinction and on the places in the landscape most important to these species. The steps in Dynamic Habitat and Population (DHP) Analysis are:1) determine which species in the planning area most merit field study based on existing data;2) use local field data to select species that most merit demographic study;3) use demographic data to model population viability of the species deemed most at risk; 4) design and evaluate alternative management strategies for key species and landscape settings.We review each step and provide an example for land birds in a portion of the Greater Yellowstone Ecosystem. Among the 143 species of land birds likely in the study area, we selected 13 species most at risk of extinction. These were mostly neotropical migrant passerines that specialized on low-elevation deciduous habitats that may serve as population source areas. We present a management plan for the multiple ownerships of the study area that seeks to maintain/restore population source habitats for key species.DHP Analysis provides a framework for biodiversity management for those regions identified as high priority for conservation by continental-scale assessment programs such as Gap Analysis. Our approach is designed to minimize local extinctions, which should reduce the risk of range-wide extinctions.

Soft water lakes with isoetids (SLI) are ecosystems prone to degradation due to the low buffer capacity of their waters. One of the main threats resulting from human impact is eutrophication due to agriculture, catchment urbanization and recreational use. In this paper, changes in the water chemistry and transformation of biocoenoses of one of the largest Polish SLI, Lake Jeleń, over the past 30 years are presented. The lake is located within the borders of a city, and a significant part of its catchment is under agriculture and recreation use. The physicochemical (concentration of nutrients, organic matter, electrical conductivity, oxygen saturation and water pH) and biological parameters (macrophytes and phytoplankton) were measured in summer 1991, 2004, 2013 and 2018. Since the beginning of the 1990s, a gradual increase in the trophy of the lake has been observed as indicated by increased nutrient availability, deterioration of oxygen conditions and a decrease in water transparency. The alterations of water chemistry induce biological transformations, in particular, an increase in phytoplankton abundance (4-fold increase of biomass in epilimnion) as well as a gradual reduction in the range of the phytolittoral (from 10 to 6 m), a decrease in the frequency of isoetids, Lobelia dortmanna and Isoetes lacustris, and expansion of plant species characteristic for eutrophy.