Streamside Management Zone Management:  Influences on Productivity and Nutrient Dynamics

Chris Colson (Presenter), Auburn University

B.G. Lockaby, Auburn University

R. Rummer, Auburn University

J. Feminella, Auburn University

R.G. Clawson, Auburn University

 Concern regarding the exclusion of timber resources in Streamside Management Zones (SMZs) from harvesting access has led to the investigation of management options that may be compatible with SMZ functions.  Three silivicultural options for management of forested SMZs are being compared using experimental watersheds.  Project objectives include comparing differences in productivity and nutrient dynamics in response to SMZ manipulation.  Each watershed consists of upland pine, deciduous SMZs, and an intermittent stream.  SMZ management options include a 1) reference, 2) partial harvest, and 3) clearcut with a weir, stilling well, and soil temperature recorders installed on each stream.  A rainfall gauge is situated in an adjacent open area.  Calibration data of streamflow, soil temperature, and rainfall was collected two years prior to harvest and continues to be monitored.  The SMZ treatments were implemented in July 1999.  Response variables include net primary productivity, litterfall, decomposition, coarse woody debris distribution, herbaceous vegetation composition, and runoff export.  Preharvest results for litterfall and aboveground woody biomass production for the control, partial, and clearcut are 809.2, 596.8, and 609.6 g/m²/yr and 73,191.1, 58,595.9, and 71,812.8 kg/ha, respectively.  Postharvest herbaceous vegetation biomass was 81.8, 127.3, and 259.3 g/m² for the control, partial, and clearcut, respectively.  Compositional differences in relation to forbs, herbs, and grasses were also observed.  Decomposition rates were directly related to the extent of disturbance.  Current litterbag % mass loss for the control, partial, and clearcut is 34.27, 25.02, and 19.98, respectively.

Workshop VII: Aquatic Ecosystems

Sustaining
Southern
Forests

a conference sponsored by the Southern Forest Resource Assessment