DOI: 10.5061/dryad.31zcrjdw6
title: Declining conifer productivity will drive future forest dynamics as climate changes in Northern New England

description: Climate change is expected to decrease habitat suitability for conifers in
 the mixed species, temperate forests of New England in northeastern USA.
 How existing forests will be affected during the transition from current
 to future growing conditions, however, is less clear, and has important
 implications for commercially-managed forests and the growing interest in
 forest carbon as a natural climate solution. We used the LANDIS-II forest
 landscape model to simulate climate change under two Representative
 Concentration Pathways (RCP 4.5 and 8.5) and interactions with timber
 harvesting under the predominant harvest regime across 4 million hectares
 of managed forestland in Maine. Using a factorial design, we compared the
 relative and cumulative impacts of predicted changes in species’ maximum
 annual net primary productivity (ANPPmax) or probability of establishment
 (SEP) on trends in live, aboveground biomass (2010-2100). In additional to
 area-wide scenario comparison, we evaluated variation in local (n = 356
 townships or ~100 km2 land units) outcomes to better inform adaptation at
 a scale relevant to forest management. Although broadleaf productivity was
 predicted to be generally resistant to regional increases in temperature
 and precipitation, projections suggested climate change will have a
 negative effect on area-wide biomass, driven predominantly by declines in
 conifer productivity. Nonetheless, conifers (specifically balsam fir
 [Abies balsamea] and red spruce [Picea rubens]) will likely remain the
 area’s most productive species; consequently, across climate scenarios
 there was a positive correlation (r = 0.68-0.82) between percent change in
 local biomass density and percent change in conifer biomass. Simulations
 also suggested that even with climate change regional harvest supply could
 be maintained over the next 70-80 years; however, current harvest rates
 and practices will become unsustainable across an increasingly large area
 as conifer productivity declines. In addition, SEP is likely to decline
 for both broadleaf and conifer trees, which will be particularly impactful
 in harvested areas with insufficient regeneration. Overall, our results
 suggest forests in Northern New England will continue to be a carbon sink
 over this century, but without adaptive management to improve forest
 resistance and resilience to climate change it will be a sink of
 diminishing capacity.
description: This archive includes the input files necessary to run LANDIS-II
 version 7. LANDIS-II must be installed, and can be downloaded for free
 from the landis-ii.org website. 
description: # Declining conifer productivity will drive future forest dynamics as
 climate changes in Northern New England
 [https://doi.org/10.5061/dryad.31zcrjdw6](https://doi.org/10.5061/dryad.31zcrjdw6) ## Description of the data and file structure Input files required to run LANDIS-II. Please note: Files are only compatible with LANDIS-II version 7. Required files for Biomass Succession extension: 1\) biomass_succession.txt, includes values required species input parameters to run LANDIS-II Biomass Succession extension. See extension user guide for description of parameters ([https://landis-ii-foundation.github.io/Extension-Biomass-Succession/](https://landis-ii-foundation.github.io/Extension-Biomass-Succession/)). 2\) normal_dynamic.txt, includes additional species parameters. Required by biomass_succession.txt. 3\) species.txt, includes values for species life history parameters. Also includes common names corresponding to species codes. 4\) ecoregions.txt, list of ecoregion names and values present in ecoregions.img. 5\) ecoregions.zip, includes all the geofiles constituting the map of ecoregions (.img,img.aux,img.vat.cpg,img.vat.dbf,.rrd). Each cell is assigned to a user-defined ecoregion, within which climate and soils are assumed to be homogeneous. We derived our ecoregions from a combination of gridded climate projections and physiographic data collected by the US Forest Service Forest Inventory and Analysis (FIA) program. The map of ecoregions is used to determine which values for species annual net primary productivity and establishment probability (listed in #2 above) are applied in a given grid cell. 6\) initial_communities.txt, list of map values and associated initial communities used for model spin-up. Information given for each map value includes species present and cohort age. 7\) ini_communities.zip, map of initial communities used for model spin-up with all associated files (.img,img.aux,img.vat.cpg,img.vat.dbf,.rrd). Available from corresponding author upon request. Required files for Base Wind extension: 1\) wind.txt, includes values for required parameters to simulate wind disturbances. See extension user guide for description of parameters ([https://landis-ii-foundation.github.io/Extension-Base-Wind/](https://landis-ii-foundation.github.io/Extension-Base-Wind/)). Required for Biomass Harvest extension: 1\) harvest_1.txt, includes harvest prescriptions and example (1 of 10) of owner implementation. See extension user guide for description of parameters ([https://landis-ii-foundation.github.io/Extension-Biomass-Harvest/](https://landis-ii-foundation.github.io/Extension-Biomass-Harvest/)). 2\) stands.zip, includes all the geofiles constituting the map of forest stands (.img,img.aux,img.vat.cpg,img.vat.dbf,.rrd). A forest stand can be delineated by any user definition, but is generally considered to be an area of forest that is homogenous in age and species composition. Our stand map was derived from a combination of a Landsat-derived disturbance time series and the same tree species data that was used to develop the initial communities map. Stands are the landscape unit upon which timber harvesting is applied. 3\) owners.zip, includes all the geofiles constituting the map of forest owners (.tif,.tif.aux,.tif.ovr,.tif.vat.cpg,tif.vat.dbf,.tfw). Ownership boundaries were purchased from Sewell Company, Old Town, Maine and reflected conditions circa 2010. Harvest rates were applied individually by owner.  ### Files and variables #### File: biomass\_succession.txt **Description:** Includes values required species input parameters to run LANDIS-II Biomass Succession extension. ##### Variables * See extension user guide for description of parameters ([https://landis-ii-foundation.github.io/Extension-Biomass-Succession/](https://landis-ii-foundation.github.io/Extension-Biomass-Succession/)) #### File: ecoregions.txt **Description:** List of ecoregion names and associated map values. ##### Variables * Active (yes/no), Map Code (integer), Ecoregion Name, Description #### File: harvest\_1.txt **Description:** Includes harvest prescriptions and example (1 of 10) of owner implementation. ##### Variables * See extension user guide for description of parameters ([https://landis-ii-foundation.github.io/Extension-Biomass-Harvest/](https://landis-ii-foundation.github.io/Extension-Biomass-Harvest/)). #### File: initial\_communities.txt **Description:** List of map values and associated initial communities used for model spin-up. ##### Variables * Information given for each map value includes species present and cohort age. #### File: normal\_dynamic.txt **Description:** Required by biomass_succession.txt. ##### Variables * Timestep, Ecoregion Name, Species, SEP (species establishment probability), ANPP (annual net primary productivity), Bmax (maximum biomass).  #### File: species.txt **Description:** Includes values for species life history parameters. Also includes common names corresponding to species codes. ##### Variables * Variable description included within file. #### File: wind.txt **Description:** Includes values for required parameters to simulate wind disturbances. ##### Variables * See extension user guide for description of parameters ([https://landis-ii-foundation.github.io/Extension-Base-Wind/](https://landis-ii-foundation.github.io/Extension-Base-Wind/)). #### File: owners.zip **Description:** Map of owner-based management units #### File: ecoregions.zip **Description:** Map of ecoregions #### File: stands.zip **Description:** Map of forest stands ## Code/software Input files are only compatible with LANDIS-II version 7, and require the following extensions be installed : Biomass Succession, Base Wind, and Biomass Harvest.