Evaluating and modeling variation in site-level maximum carrying capacity of mixed-species forest stands in the Acadian Region of northeastern North America

Currently no universal approach exists to estimate regional site-level maximum carrying capacity in terms of stand densityindex (SDIMAX) of mixed species stands across contrasting forest ecosystems. Regional research efforts that account forinfluential stand-level variables and species traits are needed to reliably derive SDIMAX under varying environmental conditions and stand characteristics. This study used regionally comprehensive forest inventory data from various permanentsampling efforts to evaluate the effects of contrasting biotic and abiotic stand- and site-level factors on SDIMAX of multiple-species, structurally heterogeneous stands of the climatically diverse Acadian Forest Region of North America. Specifically,we aimed to i) quantify the stand-level maximum size-density line for an array of forest stands found across the study area,irrespective of stand structure; ii) evaluate the relationship between this stand-specific estimate of SDIMAX and various other stand-level attributes; and, iii) develop a generalized SDIMAX prediction model using SDIMAX estimates from objective i) aswell as potential regional drivers of SDIMAX from objective ii). The most influential stand-level factors on SDIMAX were proportion of total stand basal area in hardwood species, basal area weighted mean specific gravity, range in stem diameter, andspecies diversity. Direct climatic variables were not included in our SDIMAX prediction model due to the limited variationexplained, but relationships with elevation and a site quality index based on these climatic variables were. Overall, we con-clude that i) variation in SDIMAX appears to be mostly driven by the softwood to hardwood ratio of the mixed species,structurally complex stands evaluated in our study and ii) the general approach offers a viable framework for estimating sitemaximum carrying capacity at a regional-scale and effectively managing stand density accordingly.

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Stand Structure and Composition 32 Years after Precommercial Thinning Treatments in a Mixed Northern Conifer Stand in Central Maine

Northern Journal of Applied Forestry ◽

10.1093/njaf/28.2.92 ◽

2011 ◽

Vol 28 (2) ◽

pp. 92-96 ◽

Cited By ~ 4

Author(s):

Aaron R. Weiskittel ◽

Laura S. Kenefic ◽

Rongxia Li ◽

John Brissette

Keyword(s):

Stand Structure ◽

Abies Balsamea ◽

Basal Area ◽

Long Term Effects ◽

Mixed Species ◽

Precommercial Thinning ◽

Large Trees ◽

Stand Attributes ◽

And Control

Abstract The effects of four precommercial thinning (PCT) treatments on an even-aged northern conifer stand in Maine were investigated by examining stand structure and composition 32 years after treatment. Replicated treatments applied in 1976 included: (1) control (no PCT), (2) row thinning (rowthin; 5-ft-wide row removal with 3-ft-wide residual strips), (3) row thinning with crop tree release (rowthin+CTR; 5-ft-wide row removal with crop tree release at 8-ft intervals in 3-ft-wide residual strips), and (4) crop tree release (CTR; release of selected crop trees at 8×8-ft intervals). PCT plots had more large trees and fewer small trees than the control in 2008. There were no other significant differences between the rowthin and control. The rowthin+CTR and CTR treatments had lower total and hardwood basal area (BA) and higher merchantable conifer BA than the control. CTR also resulted in more red spruce (Picea rubens [Sarg.]) and less balsam fir (Abies balsamea [L.]) than the other treatments. Although stand structures for rowthin+CTR and CTR were similar, the percentage of spruce in CTR was greater. Although the less-intensive rowthin+CTR treatment may provide many of the same benefits as CTR, the latter would be the preferred treatment if increasing the spruce component of a stand is an objective. Overall, early thinning treatments were found to have long-term effects on key stand attributes, even more than 30 years after treatment in areas with mixed species composition and moderate site potential.

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Growth Reductions in Naturally Regenerated Southern Pine Stands in Alabama and Georgia

Southern Journal of Applied Forestry ◽

10.1093/sjaf/15.2.73 ◽

1991 ◽

Vol 15 (2) ◽

pp. 73-79 ◽

Cited By ~ 11

Author(s):

G. A. Ruark ◽

C. E. Thomas ◽

W. A. Bechtold ◽

D. M. May

Keyword(s):

Pinus Taeda ◽

Growth Rates ◽

Stand Structure ◽

Basal Area ◽

Stand Density ◽

Site Quality ◽

Usda Forest Service ◽

Forest Inventory And Analysis ◽

Pine Stands ◽

Growth Differences

Abstract Data from Forest Inventory and Analysis (FIA) units of the USDA Forest Service were used to compare average annual stand-level basal area accretion onto survivor pines in naturally regenerated pine stands throughout Alabama and Georgia. Growth rates measured between 1972-82 were compared to growth rates during the previous 10-year survey cycle in each state. Separate analyses were conducted for loblolly (Pinus taeda), longleaf (P. palustris), shortleaf (P. echinata), and slash (P. elliottii) pine cover types. The unadjusted average stand-level growth rates for survivor pines 1.0 in. diameter and greater at breast height were notably lower for all cover types during the latter survey in Georgia, while only the average unadjusted growth of shortleaf was substantially lower during this period in Alabama. However, when growth rates were adjusted with regression models to account for differences in initial stand structure (stand size class, stand density, site quality class, hardwood competition, and mortality) between the two survey periods, reductions in average adjusted basal area growth ranged from 3% to 31% during the later cycle in both states. The reductions were statistically significant in almost every case. The agents causing the growth differences were not identified, but it is unlikely that stand dynamics are responsible. The observational nature of the FIA dataset precludes further resolution of causal relationships. South. J. Appl. For. 15(2):73-79.

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Modeling Height–Diameter Relationships for Mixed-Species Plantations of Fraxinus mandshurica Rupr. and Larix olgensis Henry in Northeastern China

Forests ◽

10.3390/f11060610 ◽

2020 ◽

Vol 11 (6) ◽

pp. 610 ◽

Cited By ~ 2

Author(s):

Longfei Xie ◽

Faris Rafi Almay Widagdo ◽

Lihu Dong ◽

Fengri Li

Keyword(s):

Model Validation ◽

Native Species ◽

Basal Area ◽

Tree Height ◽

Growth Period ◽

Site Quality ◽

Larix Olgensis ◽

Fraxinus Mandshurica ◽

Mixed Species ◽

Larix Olgensis Henry

The mixture of tree species has gradually become the focus of forest research, especially native species mixing. Mixed-species plantations of Manchurian ash (Fraxinus mandshurica Rupr.) and Changbai larch (Larix olgensis Henry) have successfully been cultivated in Northeast China. Height–diameter (H–D) models were found to be effective in designing the silvicultural planning for mixed-species plantations. Thus, this study aimed to develop a new system of H–D models for juvenile ash and larch mixed-species plantations, based on competition information and tree and stand attributes. The leave-one-out cross-validation was utilized for model validation. The result showed that the H–D relationship was affected not only by the tree attributes (i.e., tree size and competition information) but also by stand characteristics, such as site quality and species proportion of basal area. The best model explained more than 80% and 85% variation of the tree height of ash and larch, respectively. Moreover, model validation also confirmed the high accuracy of the newly developed model’s predictions. We also found that, in terms of total tree height, ash in middle rows were higher than those in side rows, while larch in the middle rows were higher in the early growth period but then became lower than those in the side rows, as the diameter increased. The newly established H–D models would be useful for forestry inventory practice and have the potential to aid decisions in mixed-species plantations of ash and larch.

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A Multiproduct Growth and Yield Model for the Circumboreal Aspens

Northern Journal of Applied Forestry ◽

10.1093/njaf/13.4.164 ◽

1996 ◽

Vol 13 (4) ◽

pp. 164-170 ◽

Cited By ~ 6

Author(s):

Donald A. Perala ◽

George E. Host ◽

James K. Jordan ◽

Christopher J. Cieszewski

Keyword(s):

North America ◽

Simulation Model ◽

Air Temperature ◽

Basal Area ◽

Growth And Yield ◽

Site Quality ◽

Yield Model ◽

Growth And Yield Model

Abstract A simulation model is described that grows stands of aspen of given age, site quality, and stocking from establishment to breakup. Specifying mean July air temperature allows custom application to most aspen growing regions in North America and Scandinavia. The program predicts total yields in number of trees, basal area, and biomass; and merchantable yields in cubic feet and cords for user-specified utilization standards, and in board feet, Scribner. North. J. Appl. For. 13(4):164-170.

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Mixedwood silviculture in North America: the science and art of managing for complex, multi-species temperate forests

Canadian Journal of Forest Research ◽

10.1139/cjfr-2020-0410 ◽

2021 ◽

Author(s):

Laura S. Kenefic ◽

John M. Kabrick ◽

Benjamin Knapp ◽

Patricia Raymond ◽

Kenneth Clark ◽

...

Keyword(s):

North America ◽

Stand Structure ◽

Abies Balsamea ◽

Wildlife Habitat ◽

Site Quality ◽

Northern Hardwood ◽

Seed Sources ◽

Science And Art ◽

Hardwood Species ◽

Silvicultural System

Temperate mixedwoods (hardwood – softwood mixtures) in central and eastern U.S. and Canada can be classified into two overarching categories: those with shade-tolerant softwoods maintained by light to moderate disturbances and those with shade-intolerant to mid-tolerant softwoods maintained by moderate to severe disturbances. The former includes red spruce (Picea rubens Sarg.), balsam fir (Abies balsamea (L.) Mill.), or eastern hemlock (Tsuga canadensis (L.) Carr.) in mixture with northern hardwood species; the latter includes pine (Pinus) – oak (Quercus) mixtures. Such forests have desirable socio-economic values, wildlife habitat potential, and/or adaptive capacity, but management is challenging because one or more softwood species in each can be limited by depleted seed sources, narrow regeneration requirements, or poor competitive ability. Appropriate silvicultural systems vary among mixedwood compositions depending on shade tolerance and severity of disturbance associated with the limiting softwoods, site quality, and level of herbivory. Sustainability of mixedwood composition requires that stand structure and composition be managed at each entry to maintain vigorous trees of species with different growth rates and longevities and to encourage development of advance reproduction or seed-producing trees of desired species. Regardless of silvicultural system, maintaining seed sources of limiting softwoods, providing suitable germination substrates, and controlling competition are critical. Here, we describe commonalities among temperate mixedwoods in central and eastern North America, and present a framework for managing them.

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Epiphytic biomass of a tropical montane forest varies with topography

Journal of Tropical Ecology ◽

10.1017/s0266467411000526 ◽

2011 ◽

Vol 28 (1) ◽

pp. 23-31 ◽

Cited By ~ 28

Author(s):

F. A. Werner ◽

J. Homeier ◽

M. Oesker ◽

J. Boy

Keyword(s):

Stand Structure ◽

Forest Type ◽

Regional Scale ◽

Basal Area ◽

Montane Forest ◽

Partial Replacement ◽

Slope Position ◽

Water Storage Capacity ◽

Related Matter ◽

Level Data

Abstract:The spatial heterogeneity of tropical forest epiphytes has rarely been quantified in terms of biomass. In particular, the effect of topographic variation on epiphyte biomass is poorly known, although forests on ridges and ravines can differ drastically in stature and exposure. In an Ecuadorian lower montane forest we quantified epiphytic biomass along two gradients: (1) the twig–branch–trunk trajectory, and (2) the ridge–ravine gradient. Twenty-one trees were sampled in each of three forest types (ridge, slope, ravine positions). Their epiphytic biomass was extrapolated to stand level based on basal area–epiphyte load relationships, with tree basal areas taken from six plots of 400 m2 each per forest type. Our results document the successional addition and partial replacement of lichens by bryophytes, angiosperms and finally dead organic matter along the twig–branch–trunk trajectory. Despite having the highest tree basal area, total epiphytic biomass (mean ± SD) of ravine forest was significantly lower (2.6 ± 0.7 Mg ha−1) than in mid-slope forest (6.3 ± 1.1 Mg ha−1) and ridge forest (4.4 ± 1.6 Mg ha−1), whereas maximum bryophyte water storage capacity was significantly higher. We attribute this pattern to differences in forest dynamics, stand structure and microclimate. Although our study could not differentiate between direct effects of slope position (nutrient availability, mesoclimate) and indirect effects (stand structure and dynamics), it provides evidence that fine-scale topography needs to be taken into account when extrapolating epiphytic biomass and related matter fluxes from stand-level data to the regional scale.

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Site Quality, Disturbance, and Vegetation Effects on Carbon Storage and Accumulation in Old, Mixed-Species Stands in Central Maine, USA

Natural Areas Journal ◽

10.3375/043.039.0406 ◽

2019 ◽

Vol 39 (4) ◽

pp. 429 ◽

Cited By ~ 1

Author(s):

Joshua J. Puhlick ◽

Shawn Fraver ◽

Ivan J. Fernandez ◽

Aaron Teets ◽

Aaron R. Weiskittel ◽

...

Keyword(s):

Carbon Storage ◽

Site Quality ◽

Mixed Species ◽

Vegetation Effects

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Correction to: Silvicultural prescriptions for mixed-species forest stands. A European review and perspective

European Journal of Forest Research ◽

10.1007/s10342-021-01399-4 ◽

2021 ◽

Author(s):

Hans Pretzsch ◽

Werner Poschenrieder ◽

Enno Uhl ◽

Gediminas Brazaitis ◽

Ekaterina Makrickiene ◽

...

Keyword(s):

Forest Stands ◽

Mixed Species ◽

European Review ◽

Silvicultural Prescriptions ◽

Mixed Species Forest

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A Dynamic Stand Growth Model System for Loblolly Pine Responding to Mid-Rotation Treatments

Forests ◽

10.3390/f12050556 ◽

2021 ◽

Vol 12 (5) ◽

pp. 556

Author(s):

Mauricio Zapata-Cuartas ◽

Bronson P. Bullock ◽

Cristian R. Montes ◽

Michael B. Kane

Keyword(s):

Growth Model ◽

Loblolly Pine ◽

Basal Area ◽

Model System ◽

Growth And Yield ◽

Site Quality ◽

Response To Treatment ◽

Plantation Management ◽

Vegetation Control ◽

Dominant Height

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.

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