LTRE for <i>M</i>. <i>paraensis</i> demonstrating demographic differences between harvested and unharvested plots and their contributions to population growth.

<p>LTRE for <i>M</i>. <i>paraensis</i> demonstrating demographic differences between harvested and unharvested plots and their contributions to population growth.</p

Modeling the Complex Impacts of Timber Harvests to Find Optimal Management Regimes for Amazon Tidal Floodplain Forests

<div><p>At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine-tuned management guidelines could make management more attractive, thus bridging the currently prevalent gap between tropical timber management practice and regulation.</p></div

Shifts in merchantable proportion under the 30 yr Brazilian legal management regime but without volume-based harvest limits.

<p><i>Licania heteromorpha</i> and <i>P</i>. <i>sagotiana</i> were not harvested during simulations.</p

Residual stand damage from monitored timber extraction in terms of basal area (m²) of trees >5 cm DBH killed by basal area (m²) of timber extracted.

<p>Residual stand damage from monitored timber extraction in terms of basal area (m²) of trees >5 cm DBH killed by basal area (m²) of timber extracted.</p

Differences in annualized yields (m³ yr^-1 ha^-1) between species-specific and general optimal management regimes under two STM indicators.

<p>Differences in annualized yields (m³ yr^-1 ha^-1) between species-specific and general optimal management regimes under two STM indicators.</p

Simulation-based spread of mean AY and λ_H in response to varying management criteria.

<p>Simulation-based spread of mean AY and λ_H in response to varying management criteria.</p

Potential priority areas for forest bird habitat conservation.

<p>Map is based on the number of high model reliability species projected to maintain their range between now and end of century. Current protected areas are delineated in green (National parks, State parks, Natural area reserves, wildlife refuges, sea bird sanctuaries, Nature Conservancy lands and other major private conservation areas). The pink overlay shows the spatial configuration of the main Hawaiian Islands. A similar figure including all extant species is included in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140389#pone.0140389.s007" target="_blank">S7 File</a>.</p

Potential priority areas for forest bird habitat restoration.

<p>Map is based on the identification of currently converted forest bird habitat within locations remaining climatically suitable for high model reliability species between now and end of century. The pink overlay shows the spatial configuration of the main Hawaiian Islands. A similar figure including all extant species is included in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140389#pone.0140389.s007" target="_blank">S7 File</a>.</p

Current (left) and future (right) forest bird number of species based on modeled range and available primary habitat of high model reliability species.

<p>The pink overlay shows the spatial configuration of the main Hawaiian Islands.</p

Projected changes between 1990–2010 and 2080–2100 in ranges of high model reliability species, limited to current available primary habitat.

<p>All range estimates are in km². Similar estimates for reduced model reliability species are included in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140389#pone.0140389.s008" target="_blank">S8 File</a>.</p