Balancing Revenue and Nutrient Removals in Pinus elliottii Engelm. Stands Managed for Pinestraw and Wood Production

Abstract

The forest floor is an important component for long-term forest productivity and sustainability because it plays a central role in carbon and nutrient cycling. Raking the recently senesced pine foliage off the forest floor (pinestraw raking) has become a profitable economic activity in the southeastern United States, despite its potential negative effects on long-term soil fertility. We analyzed the impact of different pinestraw raking scenarios on the profitability and carbon (C) and nitrogen (N) balance of slash pine (Pinus elliotti Engelm. var. elliottii) forests. To analyze the tradeoffs between economic returns and nutrient removals, we defined an index of ecological and economic efficiency: economic nutrient removal efficiency (ENRE), calculated as the amount of economic return (as defined by land expectation value) per unit of nutrient removed. Nutrient removals and economic returns were lower for forest stands that were managed less intensively for pinestraw raking (i.e., raking from age 8 until age 15) compared with stands managed intensively for pinestraw raking (i.e., raking from age 8 until rotation age). However, the former option was more efficient in terms of minimizing C and N removals per unit of economic return generated. Management practices that lead to increased site productivity can accelerate stand development and shorten the time to begin raking, increasing the ENRE of pinestraw raking. Stands managed exclusively for pinestraw production (with higher planting density and shorter rotations and wood harvest being a secondary objective) showed 5– 6 times lower ENRE than stands managed for traditional forestry, indicating much higher C and N removals for similar economic returns.