This represents a baseline objective reflecting
Aldo Leopold's admonition that "the first rule of intelligent tinkering is
to keep all of the parts." Most plans will benefit from including this
objective because it has the least uncertainty in the short term, and other
adaptation strategies require it as a baseline state for future projections.
The intent is to identify current patterns of biodiversity across landscapes
and reduce stressors as a way to increase the probability that key components
of biodiversity (e.g., vulnerable species, habitat cores, and high value
ecological processes) persist or improve into the future. This objective also
recognizes that species within communities are interdependent with each other
and may provide important ecological services through those interdependencies.
For example, native insect pollinator species diversity may be a key
determinant of the success of high-value fruit and vegetable farming,
especially when commercial species of pollinators such as European honeybees
are in short supply. Predator species may prevent prey population outbreaks
thereby protecting ecosystems from damaging pests. Forest tree species within
watersheds help to protect water quantity and quality.
Overview
- Assess population sizes, viability, conservation status, and phenological trends
- Map species occurrences
Details
Assessments at this level typically focus on delineating the current geographic ranges of species and highly restricted vegetation communities such as fens. Mapped information is typically based on geo-referenced data and insights on species presence gathered during scientific surveys and through the opinions of experts (e.g., natural heritage element occurrences, USGS-GAP distribution models, state wildlife agency maps). Because a wealth of existing spatial data is available in this category, most users can avoid creating their own distribution maps. A more efficient process is to establish priorities for which species to assess, then use existing distribution data to visualize the current situation or as input for predicting future distributions.
If adequate data on current distributions are not already available for the planning area, there are a wide range of approaches and tools that quantify species geographic distributions, ranging from statistical regression that relates environmental variables and species presence and absence at particular geographic coordinates, to models and algorithms that quantify likelihoods of occurrence across a landscape.
The species-level assessment may be enhanced to provide a more dynamic representation of current conditions by using population abundance and demographic data to estimate species or population viability. Population viability can be estimated for the landscape as a whole or in relation to different plant communities or land uses. This approach is often limited by the availability of spatially explicit data on population demography (e.g., age and sex structure, age-specific birth and death rates, migration rates, etc.) and abundance.
Approaches and Tools
Here is a sample of modeling approaches commonly used to estimate and map species distribution. Practitioners are also encouraged to search for and use existing species distribution maps. However, when using currently available species distribution maps it is important for the practitioners to understand and report the data and methods used to generate the maps.
Pilot Projects
Conservation Biology Institute
EcoAdapt
Geos Institute
NatureServe
Overview
- Map terrestrial and aquatic ecosystems
Details
Ecosystems – recognizable and consistent patterns of vegetation – are typically differentiated through a statistical analysis of abiotic features (e.g., soils) and vegetation observations via satellite and/or vegetation plots sampled in the field. Because a wealth of existing spatial data in this category is readily available (e.g., LANDFIRE, GAP vegetation maps, NatureServe ecosystem maps), most users can avoid developing their own classification systems and maps. A more efficient process is to use existing data on ecosystems in the focal planning jurisdiction and the surrounding landscape. Ecosystems often form the basis for evaluating potential mitigation sites, especially for wetlands.
Building an accompanying data layer that identifies the major plant and animal species that comprise the community belonging to the suite of ecosystems within the planning area can enhance an appreciation of the level of biodiversity contained within it. Ecosystem maps can also provide an important foundation for understanding ecological processes and their associated ecosystem services, if those are also part of the assessment objectives.
Approaches and Tools
- Map current footprint of ecosystem
- Map the distribution of forest trees by age classes
- Map fire history in relation to vegetation structure
Pilot Projects
Conservation Biology Institute
EcoAdapt
Geos Institute
NatureServe
Overview
Details
The landscape-level assessment aims to identify extant patterns of species and ecosystem distributions across large areas. This assessment can build on information gathered for the species and populations level by generating maps that present the aggregate of individual species distributions (i.e., provide a composite map built on individual species data layers). This composite map can be used to delineate biodiversity hotspots or quantify changes in the number and identity of species across a landscape.
Approaches and Tools
- Overlay range maps (or species distribution models) to map biodiversity hotspots
- Map the spatial genetic structure for species across the landscape to locate regions of high genetic diversity, divergence or both among species
Pilot Projects
EcoAdapt
Geos Institute
Species and populations