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

Fortini LB, Cropper WP, Zarin DJ - PLoS ONE (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: U.S. Geological Survey Pacific Island Ecosystems Research Center, Honolulu, Hawaii, United States of America.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Shifts in merchantable proportion under the 30 yr Brazilian legal management regime but without volume-based harvest limits.Licania heteromorpha and P. sagotiana were not harvested during simulations.
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pone.0136740.g002: Shifts in merchantable proportion under the 30 yr Brazilian legal management regime but without volume-based harvest limits.Licania heteromorpha and P. sagotiana were not harvested during simulations.

Mentions: The exclusion of volume-based harvest limits generally increased the rate of decline of merchantable proportion in modeled projections. For instance, without volume-based harvest limits the 30 yr Brazilian legal management regime led to a decrease in the merchantable proportion for all harvested species, but with degree of recovery related to λs (Fig 2). The rapid population turnover of species with high λs results in the stabilization of merchantable proportion at high levels before each simulated harvest (e.g., V. surinamensis and P. filipes). In contrast, species with low λs have a low ability to recover between harvests and therefore have merchantable proportions that drop after each harvest (e.g., C. spruceanum and L. mahuba). The remaining species with λs slightly above 1 stabilized at pre-harvest merchantable proportions of approximately 0.6–0.7.


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

Fortini LB, Cropper WP, Zarin DJ - PLoS ONE (2015)

Shifts in merchantable proportion under the 30 yr Brazilian legal management regime but without volume-based harvest limits.Licania heteromorpha and P. sagotiana were not harvested during simulations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556458&req=5

pone.0136740.g002: Shifts in merchantable proportion under the 30 yr Brazilian legal management regime but without volume-based harvest limits.Licania heteromorpha and P. sagotiana were not harvested during simulations.
Mentions: The exclusion of volume-based harvest limits generally increased the rate of decline of merchantable proportion in modeled projections. For instance, without volume-based harvest limits the 30 yr Brazilian legal management regime led to a decrease in the merchantable proportion for all harvested species, but with degree of recovery related to λs (Fig 2). The rapid population turnover of species with high λs results in the stabilization of merchantable proportion at high levels before each simulated harvest (e.g., V. surinamensis and P. filipes). In contrast, species with low λs have a low ability to recover between harvests and therefore have merchantable proportions that drop after each harvest (e.g., C. spruceanum and L. mahuba). The remaining species with λs slightly above 1 stabilized at pre-harvest merchantable proportions of approximately 0.6–0.7.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: U.S. Geological Survey Pacific Island Ecosystems Research Center, Honolulu, Hawaii, United States of America.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus