Generic and specific stem volume models for three subtropical forest types in southern Brazil

The purpose of this study was to prepare a comprehensive, computerized teak ( L.f) plantation yield model system that can be used to describe the forest dynamics, predict growth and yield and support forest planning and decision-making. Extensive individual tree and permanent sample plot data were used to develop tree-level volume models, taper curve models and stand-level yield models for teak plantations in Panama. Tree volume models were satisfactorily validated against independent measurement data and other published models. Tree height as input parameter improved the stem volume model marginally. Stand level yield models produced comparable harvest volumes with models published in the literature. Stand level volume product outputs were found like actual harvests with an exception that the models marginally underestimate the share of logs in very large diameter classes. The kind of comprehensive model developed in this study and implemented in an easy to use software package provides a very powerful decision support tool. Optimal forest management regimes can be found by simulating different planting densities, thinning regimes and final harvest ages. Forest practitioners can apply growth and yield models in the appropriate stand level inventory data and perform long term harvest scheduling at property level or even at an entire timberland portfolio level. Harvest schedules can be optimized using the applicable financial parameters (silviculture costs, harvesting costs, wood prices and discount rates) and constraints (market size and operational capacity).Tectona grandis

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Biomass and Volume Modeling along with Carbon Concentration Variations of Short-Rotation Poplar Plantations

Forests ◽

10.3390/f11070780 ◽

2020 ◽

Vol 11 (7) ◽

pp. 780 ◽

Cited By ~ 1

Author(s):

Lihu Dong ◽

Faris Rafi Almay Widagdo ◽

Longfei Xie ◽

Fengri Li

Keyword(s):

Carbon Sink ◽

Biomass Conversion ◽

Model Fitting ◽

National Forest Inventory ◽

Model Systems ◽

Stem Volume ◽

Crown Length ◽

Short Rotation ◽

And Performance ◽

Volume Models

Short-rotation forestry is of interest to provide biomass for bioenergy and act as a carbon sink to mitigate global warming. The Poplar tree (Populus × xiaohei) is a fast-growing and high-yielding tree species in Northeast China. In this study, a total of 128 Populus × xiaohei trees from the Songnen Plain, Heilongjiang Province, Northeastern China, were harvested. Several available independent variables, such as tree diameter at breast height (D), tree’s total height (H), crown width (CW), and crown length (CL), were differently combined to develop three additive biomass model systems and eight stem volume models for Populus × xiaohei tree. Variance explained within the three additive biomass model systems ranged from 83% to 98%, which was lowest for the foliage models, and highest for the stem biomass models. Similar findings were found in the stem volume models, in which the models explained more than 94% of the variance. The additional predictors, such as H, CL, or CW, evidently enhanced the model fitting and performance for the total and components biomass along with the stem volume models. Furthermore, the biomass conversion and expansion factors (BCEFs) of the root (118.2 kg/m3), stem (380.2 kg/m3), branch (90.7 kg/m3), and foliage (31.2 kg/m3) were also calculated. The carbon concentrations of Populus × xiaohei in root, stem, branch, and foliage components were 45.98%, 47.74%, 48.32%, and 48.46%, respectively. Overall, the newly established models in this study provided complete and comprehensive tools for quantifying the biomass and stem volume of Populus × xiaohei, which might be essential to be specifically utilized in the Chinese National Forest Inventory.

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The importance of riparian forest for the maintenance of bird species richness in an Atlantic Forest remnant, southern Brazil

Revista Brasileira de Zoologia ◽

10.1590/s0101-81752007000400027 ◽

2007 ◽

Vol 24 (4) ◽

pp. 1078-1086 ◽

Cited By ~ 16

Author(s):

Luiz dos Anjos ◽

Graziele H. Volpato ◽

Edson V. Lopes ◽

Patrícia P. Serafini ◽

Fabíola Poletto ◽

...

Keyword(s):

Atlantic Forest ◽

Riparian Forest ◽

Bird Species ◽

Southern Brazil ◽

Forest Types ◽

Forest Reserve ◽

Bird Species Richness ◽

Upland Forest ◽

Point Counts ◽

Forest Remnant

We compared the composition and guild structure of bird communities of riparian and upland forest in an Atlantic forest reserve, the Godoy State Park (GP), in northern Paraná State, southern Brazil. Unlimited distance point counts were sampled monthly from September-December 2001, along four trails. Two trails in upland forest (TA and TB) were parallel to each other and about 300 m apart. Two trails in riparian forest (TC and TD) were along the Apertados River, about 100 m away from the river. A total of 145 species were recorded: 81 species were recorded in both upland and riparian forests, 19 species were recorded only in upland forest and 45 species were recorded exclusively in riparian forest. Among the 81 species occurring in both forest types, 18 species had significantly higher numbers of contacts in the riparian forest while only 8 species had significantly higher numbers of contacts in the upland forest. Taking into account the contacts numbers of the species the large frugivores guild was closely associated to the upland forest, while bamboo and vine-tangles insectivore, canopy insectivores, edge omnivores, ground omnivore and midstory insectivores were those more closely related to the riparian forest.

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Stem volume models with random coefficients for Pinus kesiya in Tanzania, Zambia, and Zimbabwe

Canadian Journal of Forest Research ◽

10.1139/x01-019 ◽

2001 ◽

Vol 31 (5) ◽

pp. 879-888 ◽

Cited By ~ 16

Author(s):

Kalle Eerikäinen

Keyword(s):

Variable Exponent ◽

Generalized Least Squares ◽

General Assumption ◽

Random Coefficients ◽

Stem Volume ◽

Random Parameters ◽

Pinus Kesiya ◽

Taper Equation ◽

Volume Models ◽

Taper Models

The aim of the study was to estimate stem volume and taper models for Pinus kesiya (Royle ex Gordon). The volume function provides a simple prediction model for the stem volume. Taper models were developed for over- and under-bark diameters. The under-bark taper curve was determined with the variable-exponent taper equation, whereas the over-bark taper curve was derived from the predicted under-bark taper model using the variable-exponent form of the bark-thickness model. Because of the spatial correlation structures of the data, the general assumption of uncorrelated residuals did not hold. In addition, the models were assumed to contain random parameters that vary from stand to stand and from tree to tree. Therefore, the fixed and random parameters of the models were estimated with the generalized least squares technique. The results of the study show that the mixed models for stem volume and taper are more reliable volume and diameter predictors for P. kesiya than earlier taper and volume functions.

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The impact of different forest types on phytolith-occluded carbon accumulation in subtropical forest soils

Journal of Soils and Sediments ◽

10.1007/s11368-015-1259-3 ◽

2015 ◽

Vol 16 (2) ◽

pp. 461-466 ◽

Cited By ~ 12

Author(s):

Xiaodong Zhang ◽

Zhaoliang Song ◽

Kim McGrouther ◽

Jianwu Li ◽

Zimin Li ◽

...

Keyword(s):

Forest Soils ◽

Subtropical Forest ◽

Carbon Accumulation ◽

Forest Types ◽

The Impact ◽

Occluded Carbon

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Minimum sample size for fitting compatible taper-volume functions for three pine species in Chihuahua

REVISTA CHAPINGO SERIE CIENCIAS FORESTALES Y DEL AMBIENTE ◽

10.5154/r.rchscfa.2020.04.031 ◽

2020 ◽

Vol 27 (1) ◽

pp. 143-163

Author(s):

Juan M. Villela-Suárez ◽

◽

Oscar A. Aguirre-Calderón ◽

Eduardo J. Treviño-Garza ◽

Marco A. González-Tagle ◽

...

Keyword(s):

Sample Size ◽

Goodness Of Fit ◽

Small Samples ◽

Stem Volume ◽

Minimum Sample Size ◽

Forest Regions ◽

Minimum Number ◽

Minimum Sample ◽

Volume Models ◽

Volume Functions

Introduction: The choice of sample size is an important decision in the development of volume models and taper functions. Objective: To calculate the minimum sample size required for fitting compatible taper-volume functions for Pinus arizonica Engelm., P. durangensis Martínez and P. engelmannii Carr. in Chihuahua. Materials and methods: The methodology was divided into three phases: (i) fitting of a linear regression model to the diameter-height data of 50 trees of each species in the three forest regions; (ii) calculation of the minimum sample size required, and (iii) comparison of the goodness of fit of the taper-volume function using both sample sizes. Results and discussion: The minimum number of trees calculated ranged from 53 (Pinus durangensis) to 88 (P. engelmannii) and it is located in the interval reported in studies carried out to estimate the optimal sample size for the development of taper functions. No significant differences were observed in the goodness of fit (α = 0.05) in terms of the R 2 and the root mean square error, using the full sample size and the calculated minimum sample size; no significant effect was observed in the stem volume estimates. Conclusion: The use of small samples in the fit of taper-volume models generates accurate estimates if adequate representation of the study population is ensured.

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Selection and use of calling site by Boana leptolineata and Phyllomedusa distincta during the reproductive season

Iheringia Série Zoologia ◽

10.1590/1678-4766e2021013 ◽

2021 ◽

Vol 111 ◽

Author(s):

Renata K. Farina ◽

Camila Paraboni ◽

Daniela Figueiró ◽

Mateus Raguse-Quadros ◽

Charles F. dos Santos ◽

...

Keyword(s):

Reproductive Success ◽

Climatic Conditions ◽

Subtropical Forest ◽

Wetland Vegetation ◽

Reproductive Season ◽

The Body ◽

Behavioral Characteristics ◽

Southern Brazil ◽

Microhabitat Structure ◽

Selection Of

ABSTRACT Climatic conditions and microhabitat characteristics, such as the substrate and type of vegetation, influence the choice of male anurans for calling sites that optimize their reproductive success. We evaluated the structure and selection of vocalization microhabitat of 17 individuals of Phyllomedusa distincta Lutz, 1950 and 25 of Boana leptolineata (Braun & Braun, 1977), in a subtropical forest in southern Brazil. We measure the height of the perch, the distance between the perch and the edge of the body of water and the structure of the microhabitat of quadrants used by individuals. The same attributes were measured in the quadrants available (but not used) by the individuals. We classified the microhabitats by visual estimate, assigning percentages of coverage for each quadrant by herbaceous, shrub, tree and wetland vegetation. We observed that both species selected their microhabitat, since the characteristics of the quadrants occupied by the individuals were different from those available. Phyllomedusa distincta was more associated with heterogeneous microhabitats, while B. leptolineata occurred in environments with greater coverage of tree strata. Additionally, we observed that both species used shrubs more frequently as a perch site. The selection of these microhabitat characteristics must be associated with strategies to optimize the use of the reproductive habitat, based on the morphological and behavioral characteristics of the species. Finally, it is possible to infer that the differences observed in the microhabitat structure selected by the species can facilitate the coexistence of both in the context of the heterogeneity of the environment.

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