Ecosystem Diversity Requirements: The Challenge of Maintaining Everything

The above chart is from the Convention on Biological Diversity website here.

My question: do we really understand what requiring maintenance and restoration of ecosystem diversity means under 219.9 ? At least we have some idea of what vertebrate species are or aren’t (except for them crossing with each other, but at least that is something concrete and observable (genetically, at least)).

From the proposed rule:

(a) Ecosystem Diversity. The plan must include plan components to maintain or restore the structure, function, composition, and connectivity of healthy and resilient terrestrial and aquatic ecosystems and watersheds in the plan area, consistent with § 219.8(a),
to maintain the diversity of native species.

I had a definition of ecosystem composition in my head, but here are a couple from the internet.. I italicized the composition-relevant parts. Caveat: I did not independently track these to their origins, but simply copied from this site.

# Edward Grumbine, “Ghost Bears: Exploring the Biodiversity Crisis,” 1993:

“There is much more to biodiversity than the numbers of species and kinds of ecosystems. Ecologist Jerry Franklin portrays ecosystems as having three primary attributes: composition, structure, and function.

Ecosystem components are the inhabiting species in all their variety and richness. Many different species, gene-pool abundance, and unique populations are what most people think of when they hear the term “biodiversity”. But there is much more to consider.

Ecosystem structure refers to the physical patterns of life forms from the individual physiognomy of a thick-barked Douglas-fir to the vertical layers of vegetation from delicate herbs to tree canopies within a single forest stand. An ecosystem dominated by old, tall trees has a different structure than one comprised of short, quaking aspen. And there is more structure in a multilayered forest (herbs, shrubs, young trees, canopy trees) than in a single sagebrush grassland, prairie, or salt marsh…

Ecosystem functions are hard to see in action. “You can’t hug a biogeochemical cycle,” says one ecologist. But without the part of the carbon cycle where small invertebrates, fungi, and microorganisms work to break down wood fiber, the downed logs in an ancient forest would never decay. Natural disturbances also play a role. Wildfires release nutrients to the soil, weed out weak trees, and reset the successional clock. The energy of falling water creates spawning beds for salmon even while it carves a mountain’s bones. Plants breathe oxygen into the atmosphere. Ecological processes create landscapes and diverse environmental conditions out of life itself.

Ecosystem components, structures, and functions are all interdependent. To understand biodiversity, one has to think like a mountain and consider not only the biotic elements of plants, animals, and other living beings, but also the patterns and processes that shape volcanoes and forests.”

# Reed Noss, “Indicators for Monitoring Biodiversity: A Hierarchical Approach,” Conservation Biology 4(4):355-364. 1990:

“Biodiversity is not simply the number of genes, species, ecosystems, or any other group of things in a defined area…A definition of biodiversity that is altogether simple, comprehensive, and fully operational (i.e. responsive to real- life management and regulatory questions) is unlikely to be found. More useful than a definition, perhaps, would be a characterization of biodiversity that identifies the major components at several levels of organization.

…(C)omposition, structure, and function…determine, and in fact constitute, the biodiversity of an area. Composition has to do with the identity and variety of elements in a collection, and includes species lists and measures of species diversity and genetic diversity. Structure is the physical organization or pattern of a system, from habitat complexity as measured within communities to the pattern of patches and other elements at a landscape scale. Function involves ecological and evolutionary processes, including gene flow, disturbances, and nutrient cycling.”

It’s pretty clear from the preamble that species are not included in the ecosystem definition in the proposed rule, although the usage of the term generally of “ecosystem composition” may include species as one of the components.

Here’s the preamble, which is very clear.

Ecosystems are described in terms of their composition (vegetation types, rare
communities, aquatic systems, riparian systems); structure (vertical and
horizontal distribution of vegetation, stream habitat complexity, and riparian
habitat elements); function (processes such as stream flows, nutrient cycling,
and disturbance regimes); and the connection of habitats (for breeding,
feeding, or movement of wildlife and fish within species home ranges or
migration areas). Healthy ecosystems are indicated by the degree of ecological
integrity related to the completeness or wholeness of their composition,
structure, function, and connectivity.

Nevertheless, I have to wonder if we have moved from an interest in the concrete vertebrates to being responsible for aspects of the ecosystem we don’t even know, understand, and possibly can’t measure. Will we have case law around maintenance of nutrient cycling? Disturbance regimes? How are we supposed to maintain or restore them if they are changed through climate change? This section bristles with a variety of potential legal hooks and complex analytical and monitoring requirements.

3 thoughts on “Ecosystem Diversity Requirements: The Challenge of Maintaining Everything”

  1. Since we are dealing with matters largely incomprehensible to average forest plan participants, we might as well flesh out § 219.8(a) which is embedded in the snippet you posted:

    § 219.8(a) Ecological sustainability.
    (1) Ecosystem plan components. The plan must include plan components to maintain or restore the structure, function, composition, and connectivity of healthy and resilient terrestrial and aquatic ecosystems and watersheds in the plan area, taking into account:
    (i) Landscape-scale integration of terrestrial and aquatic ecosystems;
    (ii) Potential system drivers, stressors, and disturbance regimes,
    including climate change; how they might affect ecosystem and watershed
    health and resilience; and the ability of those systems on the unit to
    adapt to change;
    (iii) Air quality; and
    (iv) Wildland fire and opportunities to restore fire adapted ecosystems.
    (2) Ecosystem elements. The plan must include plan components to maintain, protect, or restore:
    (i) Aquatic elements, such as lakes, streams, wetlands, stream banks, and shorelines;
    (ii) Terrestrial elements, such as forest stands, grasslands, meadows, and other habitat types;
    (iii) Rare aquatic and terrestrial plant and animal communities, consistent with § 219.9;
    (iv) Public water supplies, sole source aquifers, source water protection areas, groundwater, and other bodies of water (including guidance to prevent or mitigate detrimental changes in quantity, quality, and availability, including temperature changes, blockages of water courses, and deposits of sediments); and
    (v) Soils and soil productivity (including guidance to reduce soil erosion and sedimentation).
    (3) Riparian areas. The plan must include plan components to maintain, protect, or restore riparian areas. Plans must establish a default width for riparian areas around all lakes, perennial or intermittent streams, and open water wetlands, within which these plan components will apply. The default may be a standard width for all lakes, perennial or intermittent streams, and open water wetlands, or may vary based on ecologic or geomorphic factors, or the type of waterbody. The default width will apply unless the actual riparian area for a waterbody or a site has been delineated based on best available scientific information.

    I would love to see how this particular sausage was made. In the early days of forest planning a good friend was fond of saying that we ought to force all those who write this stuff — rules, manuals, handbooks, etc. — to come to a forest and try to implement it.

    [3/21 Update]: Note that “my good friend” was not your “average” forest plan participant. He was perhaps the best educated “operations research analyst” that the Forest Service ever saw–and arguably the best one the FS ever saw. After his stint on the Lolo NF, he went over to Ft. Collins to serve as key facilitator in the FORPLAN arena. After several frustrating years in Ft. Collins he left the FS and went to places where he could actually use his “systems analysis” expertise.

    Not that I’m defending FORPLAN, which I too played key roles in developing/facilitating. After I saw how the FS was using FORPLAN, I began to campaign against it and other “quantative analysis”. I began campaigning too against nonsense economics, nonsense planning, and nonsense management. I’m still waging war on those three fronts, although I take some comfort in the fact that the FS no longer champions economics the way it used to.

  2. When riparian buffers extend outside of the watershed boundaries, you know something is wrong with “the system”. How about “sensible” buffers, instead of locking up land, like ridgetops, which requires no “riparian protection”?

  3. Thanks for posting on this important topic Sharon; it doesn’t get enough attention as far as I’m concerned. Unfortunately the proposal’s ecosystem diversity language is littered with enough ecological inconsistencies and ambiguity to make it nearly impossible to unpack from an implementation perspective.

    First, asserting that ecosystems are composed of vegetation types and “aquatic systems” is not consistent with ecological principles and in direct conflict with the 1999 Committee of Scientists report. (Saying a system is composed of another system borders on the philosophical.) Here is the COS definition of “composition” from Chapter 3 (p. 19):

    “Composition refers to the biodiversity of an ecological system, including genetic, species, and landscape diversity. Genetic diversity is the variation in inheritable characteristics within and among individual organisms and populations. Species diversity is the number of different kinds of species present in a given area. Landscape diversity is the variety of plant communities (including their identity, distribution, juxtaposition, and seral stage) and habitats evaluated at the landscape scale.”

    The COS go on to discuss the role of individual species within an ecosystem approach (p.36):

    “The emphasis on composition, structure, and processes within ecological systems directs the focus to broad spatial scales and large landscapes. A systems approach gives equal emphasis to the components of the system (i.e., the individual species).”

    I don’t think the current proposal has given equal emphasis to the components of the system; individual species. Clearly the proposal is dubbing “ecosystem diversity” as what the COS would term “landscape diversity” and asserting the the maintenance of landscape diversity will maintain species diversity. Of course, this is an assumption that has been regularly criticized in the biodiversity literature, as discussed by the COS, again in Chapter 3 (pp.19-20):

    “Habitat alone cannot be used to predict wildlife populations, however. The presence of suitable habitat does not ensure that any particular species will be present or will reproduce. Therefore, populations of species must also be assessed and continually monitored.”

    Which brings us to the role of focal species, which the COS and 2000 rule completely embraced, but are completely relegated to the sidelines in this proposal. As I have said many times, it is the failure of this proposal to define and set parameters for “species diversity” that renders it ecologically flawed.

    This point is made abundantly clear by the COS, who clearly linked the concept of diversity to the measurement of species viability so as to avoid the flawed logic found in the proposal (again p.36):

    “Diversity is sustained only when individual species persist; the goals of ensuring species viability and providing for diversity are inseparable.”

    As a side note, the proposal’s notion that resiliency leads to species diversity could very well be putting the effect before the cause. According to the Convention on Biological Diversity’s Forest Resilience, Biodiversity and Climate Change synthesis (

    “The available scientific evidence strongly supports the conclusion that the capacity of forests to resist change, or recover following disturbance, is dependent on biodiversity at multiple scales. Maintaining and restoring biodiversity in forests promotes their resilience to human-induced pressures and is therefore an essential ‘insurance policy’ and safeguard against expected climate change impacts. Biodiversity should be considered at all scales (stand, landscape, ecosystem, bioregional) and in terms of all elements (genes, species, communities) (p.7).”

    So rather than managing forests for vague notions of “health” and “resilience” and hoping that biodiversity will follow, perhaps the agency should focus on measurable aspects of biodiversity first, and let “health” and “resilience” be the outcomes. I’ll be extremely curious to see what external science reviewers make of the proposal’s wobbly ecological logic.


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