Ecological Resiliency Management Planning

Managing for Ecological Resiliency

Castor Peak Catchment Solutions (CPCS) is putting ecological resiliency theory into practice for natural resource managers.

Ecological resiliency is the capacity of an ecosystem to absorb disturbance and reorganize in such a way as to retain dynamic equilibrium in structure and function (Walker & Salt, 2012). Ecosystems evolve, adapt, reorganize and repair themselves within levels of disturbance. The foundation of ecological resiliency is built upon the innate adaptive capacity of the ecosystem to evolve and adapt to external fluctuations. The ability of an ecosystem to absorb disruption is dependent on the controlling variables and adaptive capacity of biota within the ecosystem.

We focus catchment data collection and analysis on wetland ecosystems and drainage patterns within the catchment. Basic upland vegetation assessment is completed and the upland regions are mapped according to dominant vegetation. Water is the primary driver of productivity, stability, and functionality of western watersheds. Understanding supply, capture, and containment of water resources is essential for resiliency management planning in semi-arid to hyper-arid ecosystems.

For catchments located within arid regions we are concerned with how water is held and moves across the landscape.  We: 1. Evaluate site capacity potential in slowing the movement of water from high elevations to low elevations, 2. Inform managers as to the best locations for increasing capture and residence time of water across the catchment, 3. Work with managers to enhance wetland water holding capacity.

We also focus on trait-based ecology to inform our wetland functionality rating and determination of specific site resiliency. CPCS is creating an innovative standard with which to measure wetland resiliency from plant functional traits. We collect data for wetland research purposes as well as for natural resource management purposes. We are currently working on collecting data for over 1200 species commonly found in wetlands located in western North America. We look at plant traits in combination with site soil and hydrology to evaluate the capacity of the wetland to: 1. Trap sediment 2. Reduce the energy/flow velocity of water through the catchment 3. Adapt to change 4. Accumulate and store water and 5. Store carbon.

PFT_PlantList

Analysis and Assessment: CPCS utilizes plant functional traits to explain and gauge ecosystem properties. When possible we collect data using numerical values i.e. quantitative. However, when this is not possible, we have defined ordinal categorical traits to group species into layer values from lowest to highest through qualitative evaluation.

CPCS evaluates streams and wetlands within a catchment for site potential and ecological resiliency and for streams, dynamic equilibrium. Assessment criteria is overlapping. We use the data we collect when assessing ecological resiliency and stream dynamic equilibrium to determine site potential. Initial background analysis is completed using USGS stream, watershed and climate data and USDA soils and climate data along with state soil information where available to make initial evaluation of catchment geology, climate and soils. More comprehensive field data collection involves both existing methodology and new CPCS methodology to collect stream and wetland data.

We also identify and or classify and map/delineate:

  1. Special needs areas (headcuts, invasive species dominated, burned or within sediment flow of burned area, highly eroded, incised channels, etc.)
  2. Ecosystem adaptive cycle stages (reorganization, exploitation, conservation, release)
  3. Stream successional stages (Rosgen level III) & wetland USFWS classification
  4. Disturbance regime (multiple use parameters, fire, invasive species, or communities with disease or insect infestations)
  5. Landform (Rosgen)

Wetland resiliency assessment and stream dynamic equilibrium considers the following aspects:

*Data collection and field methodology utilized is by wetland type i.e. lentic or lotic.

  1. Functional condition
    1. Size function for both lentic & lotic wetlands
      • Shrinking, expanding, disconnected from stream, at maximum size potential
    2. Salinity
    3. pH
    4. Vegetation
      • Age class
      • Height
      • Species diversity
      • Microsite formation (hummock hollow, canopy)
      • Density
      • Functional traits
        • Root length/depth
        • Root volume
        • Fine root hair abundance
        • Stem growth form & or basal area formation
        • Stem density
        • Clonality
        • Vegetative spreading rate
        • Colony formation
        • Life strategy, lifespan, growth rate
        • Adaptation to change
          1. Fire tolerance
          2. Soil adaptation
          3. Salinity tolerance
          4. Anaerobic tolerance
          5. Fertility requirements
          6. CaCO3 tolerance
          7. Shade tolerance
          8. Drought tolerance
          9. pH range
          10. Precipitation range
          11. Ability to handle fluctuations in the water table
        • Water use efficiency (WUE)
        • Carbon to Nitrogen ratio
      • Connection to other waterbodies or wetlands within the catchment
      • Habitat provision (using vegetative data)
      • Stability (using MIM & Rosgen level III)
      • Soils
        1. Compaction
        2. Porosity
    5. Sinuosity
    6. Depositional patterns
    7. Channel blockages
    8. Degree of channel incision & width to depth ratio
    9. Streambank assessment
      • Root depth & density
      • Bank slope
      • Bank material
      • Current bank condition
    10. Pool & Riffle formation
    11. Streambed sediment
    12. Water clarity
    13. Temperature

Stream & wetland site potential assessment consider the following aspects:

* Site function potential is based on cumulative data collected from ecological resilience

  1. Size & order
  2. Location in watershed
  3. Hydrology and flow pattern
  4. Meander potential & patterns
  5. Flow regime (using Rosgen level III general & specific categories)
  6. Gradient/slope
  7. Underlying geology
  8. Soils
    • Type (sand, silt, & clay content)
    • Structure
    • Aggregate stability
  9. Vegetation
    • Functional trait diversity
      1. Root systems (see resiliency parameters)
      2. Above ground vegetative growth (see resiliency parameters)
    • Adaptive capacity (see resiliency parameters)
    • Water use efficiency
  10. Sediment capture
  11. Habitat provision
  12. Connectivity
  13. Water holding capacity
  14. Site overall adaptive capacity
  15. Stability

Walker, B., & Salt, D. (2012). Resilience Practice: Building Capacity to Absorb Disturbance and Maintain Function. Washington: Island Press.