An Ecosystem Management Approach to Riparian Zones

1. An Ecosystem Management Approach to Riparian Zones Joy O’Keefe Clemson University

2. Ecosystem Management • Promotes sustainability of ecological processes • Recognizes ecosystems are dynamic and complex • Considers future economic, social, ecological factors • Necessitates cooperation across boundaries • Requires accurate complex data and tools • Integrates research and management

3. Ecosystem Management • Adaptive management necessary to deal with uncertainty and new data • No more stand-level management  now landscape-level • Shift from single species to ecosystem approach, but consider keystone species

6. Riparian Zones “land near streams and rivers” unique characteristics and functions But, as a land manager, how do you define and manage a riparian zone?

7. Riparian Zone Functions • filter sediments, nutrients • stabilize stream banks • energy source for aquatic systems • provide shade • moist habitat • travel route • economic, social, recreational uses

8. Impacts on Riparian Zones • Intensive land use • Changes in disturbance (e.g. lack of fire) • Pollution • Introduction of exotic pests (e.g. hemlock adelgid)

9. Multidisciplinary Approach • Research riparian zone structure & function • vegetation, wildlife, nutrients, sediments, CWD, water quality, keystone spp., ecosystem services • Management Options • timber harvest buffers, rhododendron control, fire, fertilization, planting • Evaluation • Riparian zones responses: structure, function, and ecosystem services

10. Bats: Tools to Study Function For bats, riparian zones provide foraging, drinking, and roosting habitat, and serve as flight corridors

11. Again, how do you define and manage riparian zones for bats? Definition and management strategies will vary: • geographically • seasonally • by stream size • by bat species • by function

12. 1st or 2nd Order Streams ??

13. 5th of Higher Order Streams ??

14. Rivers ??

15. Riparian Management Instream management Prey availability Instream structure Clutter Streamside vegetation community composition Roost site availability and characteristics Streamside management Streamside buffers Water From Hayes and Loeb presentation, Bats and Forests Symposium, 2004

16. Instream Structure • Maintain water quality by controlling pollution and sediment input • Maintain bank trees for stability • Encourage retention of coarse woody debris • Use indicator species presence as monitoring tools

17. Riparian Management Instream management Prey availability Instream structure Clutter Streamside vegetation community composition Roost site availability and characteristics Streamside management Streamside buffers Water From Hayes and Loeb presentation, Bats and Forests Symposium, 2004

18. Streamside Vegetation and Community Composition • Retain trees that function as shade trees (e.g. hemlock) or roosts (e.g. birch) • Control rhododendron • Leave standing dead trees (potential roosts) • Pest control (e.g. hemlock wooly adelgid) • Burn and/or thin to reduce clutter and control community composition

19. Riparian Management Instream management Prey availability Instream structure Clutter Streamside vegetation community composition Roost site availability and characteristics Streamside management Streamside buffers Water From Hayes and Loeb presentation, Bats and Forests Symposium, 2004

20. Streamside Buffers • Identify optimal width: • To maximize timber harvest • Varies with topography and stream order • Depends on function to be maintained: • Retention of roosts • Sheltered flight corridor • Suitable prey base (by diversity and abundance)

21. Acoustic Sampling Activity levels Species presence Temporal patterns Spatial patterns Capture/Radio Telemetry Species presence Roost habitat Foraging habitat Temporal patterns Spatial patterns Tools to Study Bats

22. Acoustic Sampling • Allows simultaneous sampling in a variety of habitats • Record calls of free-flying bats within 50 ft radius of microphone • System can be left unattended for several days

23. Anabat II detectors, CF Storage ZCAIMs • Detectors record calls from 20:30 to 6:30 each night • Calls stored on flash card • Examine calls with Analook software • Identify species with discriminant function model • Determine activity by habitat using call count

24. To be harvested 150 150 75 75 No harvest Primary Experimental Design Four treatments 3 Anabats per trtmnt 0 100 ft 75 0 Stream Control 150 0 30 ft 0 75 0 ft 150

25. Secondary Experiment • Simultaneous acoustic surveys in multiple habitats for comparison • Two watersheds • 7 – 10 July 2004 (an active time for bats in the mountains)

26. Presence by Habitat Type

27. Activity by Habitat Type < 1% < 1% 10% 11% 12% 66% < 1% < 1% Activity varied by habitat type (p=0.002)

28. Capture • Mistnet over roads, streams, and ponds • Survey as often as possible! • Collect data on individual bats • species, sex, age, weight, forearm length, reproductive state, and band # • Select some captures for radio telemetry

29. Radio Telemetry • Attach transmitters to bats that roost in foliage (eastern red bat and eastern pipistrelle) and crevices/bark (northern bats, small-footed bats, big brown bats)

30. Radio Telemetry • Track bats to roost trees daily

31. Radio Telemetry • Collect data on roosts and random trees

32. Brief Telemetry Results • Eastern red bat (foliage) • Hickory, oak, birch, sourwood trees • Not restricted to riparian zone or to one stand type/age • Eastern pipistrelle (foliage) • Birch and oak trees very close to small stream • Northern bat (crevice/bark) • Large hardwood snags in older stand on upland site