TIMBER HARVESTING AND PROCESSING IN THE NORTHEASTERN UNITED STATES EMPLOYS OVER HALF A MILLION PEOPLE AND GENERATES OVER $20 BILLION PER YEAR. THE REGION ALSO SUPPLIES ONE-FOURTH OF THE NATION'S WOOD VOLUME, TO MEET THE GROWING DEMAND FOR WOOD-PRODUCTS AND BIOFUELS. HOWEVER, TIMBER HARVESTS ARE DECREASING DUE TO SHIFTS IN LAND-MANAGEMENT, BIOTIC STRESSES, AND NUTRIENT LIMITATIONS. THE EFFECTS OF HARVESTING SEVERITY AND REPEATED HARVESTS ON LONG-TERM NUTRIENT SUSTAINABILITY IS UNCERTAIN, BUT NET LOSSES OF BASE CATION NUTRIENTS (E.G. CALCIUM, MAGNESIUM, AND POTASSIUM) CAN RESULT IN DECREASED WOODY BIOMASS, POTENTIALLY GREATER THAN THE 20%, AS SEEN IN SCANDINAVIAN FORESTS. HERE, WE PROPOSE QUANTIFYING NUTRIENTS IN SOILS AND MINERALS AND THEIR EFFECTS ON ABOVEGROUND BIOMASS ACROSS MANAGEMENT TYPES AND HARVESTING SEVERITIES. FURTHER WE PROPOSE TO EXPLORE LIME AND ASH AMENDMENTS TO ADD LOST NUTRIENTS AND INCREASE TREE GROWTH RATES AND WOODY BIOMASS. WE WILL CONDUCT FIELD STUDIES ON NUTRIENT CYCLING AND ACQUISITION EXPERIMENTS AT FOUR EXPERIMENTAL FORESTS WITH DIFFERENT NUTRIENT AVAILABILITIES IN NORTHEASTERN UNITED STATES. WE WILL DETERMINE NUTRIENTS SOURCED FROM MINERAL WEATHERING AND RECYCLED PLANT MATERIALS USINGNOVEL MINERAL DISSOLUTION EXPERIMENTS AND NEW APPLICATIONS OF STABLE ISOTOPES (Δ44CA, Δ26MG, AND Δ41K) TO SOILS AND VASCULAR SOLUTIONS. LASTLY, WE WILL USE OUR EMPIRICAL DATA ACROSS HARVESTING SEVERITIES TO PARAMETERIZE, A PROCESS-BASED FOREST GROWTH MODEL (E.G. FORNBM), TO ESTIMATE CHANGES IN BIOMASS AND MERCHANTABLE WOOD FROM NUTRIENT LOSSES AND THE EFFECTIVENESS OF FERTILIZATION. PRACTICAL ADOPTION FROM OUR STUDIES WILL BE ACHIEVED BY MEETING WITH FOREST MANAGERS AND PROVIDING DATA ON LONG-TERM SITE SUSTAINABILITY AND PRODUCTIVITY.

University Of Massachusetts, Amherst MA

Investigators