Riparian Management Zones (RMZs) are allocated around streams to ensure the continuous production of riparian ecosystem functions and minimize potential disturbances from forest management activities. However, allocating RMZs can result in a burden to landowners due to restrictions (sometimes prohibitions) on harvesting. The opportunity cost for the landowner may be minimized by shifting the primary management objective in RMZs from timber production to compensation for above-ground carbon. Our primary objective was to compare long-term revenue generating potential of RMZs under three scenarios: (I) compensation for carbon credits without harvesting; (II) partial harvesting using BMP guidelines without carbon credits; (III) partial harvesting combined with carbon credits as per the California Compliance Offset Protocol.
Basic stand data on trees of 1 inch and higher were collected in riparian forest plots along headwater streams within the Huntington Wildlife Forest (HWF) in NYS (hardwood) and Hubbard Brook Experimental Forest (HBEF) in NH (mixed-wood). The USFS Forest Vegetation Simulator was used to simulate growth and yield, and schedule management activities over 20-year cutting cycles. Timber volumes and registry offset credits along with their market values were calculated for the respective scenarios and a cost-benefit analysis was performed under assumptions of constant price and inflation.
Results/Conclusions
The initial aboveground carbon stocks at both locations were 32% (HWF) and 140% (HBEF) higher than the average value for their assessment areas. When prices are adjusted for inflation, the unit area Net Present Value (NPV) for Scenario I ranged from -$48/ac to $202/ac in HWF and $73/ac to $430/ac in HBEF. For Scenario II, the NPV ranged from $383/ac to $1,331/ac in HWF and $130/ac to $364/ac in HBEF and for Scenario III, the NPV ranged from $200/ac to $430/ac in HWF from $134/ac to $383/ac in HBEF.
HWF will profit more by not participating in the carbon markets and pursuing partial harvesting as per BMP guidelines (Scenario II). HBEF will profit more by participating in the Carbon Markets either in a no harvesting scenario or under a partial harvesting as per guidelines in the Protocol.
A protocol for compensating landowners for riparian carbon offsets provides an opportunity to generate stumpage revenues in scenarios in which state BMP guidelines may restrict or outright prohibit harvesting in RMZs. Given the high density of ecologically critical headwater streams in the Northeast and potential RMZ restrictions, the carbon offset option provides landowners with the opportunity to remain economically viable.