Economic trade-offs of managing forests for timber production and vegetative diversity

1994 ◽  
Vol 24 (6) ◽  
pp. 1260-1265 ◽  
Author(s):  
David N. Holland ◽  
Robert J. Lilieholm ◽  
David W. Roberts ◽  
J. Keith Gilless
Keyword(s):  
Diversity Index ◽  
Basal Area ◽  
Timber Harvest ◽  
Forest Stand ◽  
Timber Production ◽  
Harvest Scheduling ◽  
Scheduling Model ◽  
Trade Offs ◽  
Compositional Diversity ◽  
Shannon’S Diversity Index

Three indices of forest stand structural and compositional diversity were incorporated into a linear programming timber harvest scheduling model to examine the trade-offs between managing stands for timber production and biodiversity objectives. The indices, based on Shannon's diversity index, characterized stand species diversity, basal area diversity, and vertical crown diversity. While harvest-level objectives were often compatible with the maintenance of vegetative diversity, the maximization of present net value was accompanied by substantial reductions in all three measures of diversity.

scholarly journals Impacts of artificial reservoirs on floristic diversity and plant functional traits in dry forests after 15 years

2015 ◽  
Vol 75 (3) ◽  
pp. 548-557
Author(s):  
SF Lopes ◽  
VS Vale ◽  
JA Prado Júnior ◽  
I Schiavini
Keyword(s):  
Human Services ◽  
Diversity Index ◽  
Basal Area ◽  
Dry Forest ◽  
Ecological Functions ◽  
Tree Community ◽  
Random Samples ◽  
Floristic Data ◽  
Shannon’S Diversity Index ◽  
Artificial Reservoirs

AbstractDams are of paramount importance to a wide variety of human services and many of their environmental problems are known; however, there are few studies in the world addressing the impacts on the native vegetation previously distant from water bodies which became close to the lakeshore created by a dam. Thus, this paper aims to analyze the responses of a dry forest to a dam after 15 years. For this, 20 random samples of 40 trees were made, 10 close to the lakeshore and 10 distant from it, by applying the central square point method. Close to the dam, we found higher values regarding basal area, number of trees, number of evergreen trees, and zoochoric syndrome, but there were lower values of Shannon’s diversity index. Therefore, the impacts of the dam after 15 years caused several changes to the tree community. The greater basal area close to the dam suggests that water deficit during the dry season was decreased and plants have thicker trunks. On the other hand, this sector had much more zoochoric syndrome and a larger number of evergreen trees than plots which are distant from water, suggesting changes with regard to the community’s ecological functions. Furthermore, structural floristic data shows that the sector close to the dam is less similar to other deciduous forests within the same geographical region than the sector distant from water, thus providing evidence of the impacts of dams on the tree community.

Evaluation of two risk mitigation strategies for dealing with fire-related uncertainty in timber supply modelling

2010 ◽  
Vol 40 (6) ◽  
pp. 1136-1154 ◽  
Author(s):  
David W. Savage ◽  
David L. Martell ◽  
B. Mike Wotton
Keyword(s):  
Risk Mitigation ◽  
Timber Harvest ◽  
Fire Regimes ◽  
Mitigation Strategies ◽  
Planning Model ◽  
Harvest Scheduling ◽  
Scheduling Model ◽  
Risk Mitigation Strategies ◽  
Harvest Volume ◽  
Forest Managers

We embedded a linear programming timber harvest scheduling model into an aspatial stochastic simulation model of a flammable forest to evaluate two fire risk mitigation strategies. The harvest scheduling model is solved repeatedly to produce harvest schedules within a rolling planning horizon framework. The risk mitigation strategies we examined were (1) whether or not to account for fire in the planning model and (2) replanning interval. We evaluated those strategies under four representative fire regimes. We found that accounting for fire in the planning model reduced the harvest volume variability as fire activity increased (i.e., for average annual burn fractions ≥0.45%), but replanning intervals over a range of 1 to 10 years had little impact on harvest volume variability. We also developed a risk analysis decision-making aid that forest managers can use to help deal with fire-related uncertainty. Our results suggest that risk-averse forest managers should account for fire while planning, especially when burn fractions exceed 0.45%.

An operational, spatially constrained harvest scheduling model

1990 ◽  
Vol 20 (9) ◽  
pp. 1438-1447 ◽  
Author(s):  
Stephen E. Clements ◽  
Patrick L. Dallain ◽  
Mark S. Jamnick
Keyword(s):  
Monte Carlo ◽  
New Brunswick ◽  
Timber Harvest ◽  
Programming Algorithm ◽  
Search Procedure ◽  
Harvest Scheduling ◽  
Short Term ◽  
Mapping Strategy ◽  
Scheduling Model

A Monte Carlo integer programming algorithm was developed to generate short-term (25-year), spatially feasible timber harvest plans for a New Brunswick Crown license. Solutions for the short-term plan are considered feasible if they meet spatial and temporal harvest-flow and adjacency constraints. The solution search procedure integrates a randomly generated harvesting sequence and checks of harvest-flow and adjacency constraints. The model was used to determine the annual allowable cut under three constraint formulations. The three formulations represented increasing levels of adjacency constraints, from no constraints to levels similar to current provincial requirements. The annual allowable cut under the most strict constraint formulation was reduced by 9% from the unconstrained formulation, for a given mapping strategy of a long-term harvest schedule. These applications of the model indicate that it is suitable for spatially constrained harvest scheduling on Crown licenses in New Brunswick.

Floristic Variation of Tree Communities and Their Association with Soil Properties in Pulau Jerejak, Penang, Peninsular Malaysia

2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi
Keyword(s):  
Tree Species ◽  
Diversity Index ◽  
Basal Area ◽  
Peninsular Malaysia ◽  
Importance Value ◽  
Conservation Action ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Tree Communities ◽  
Floristic Variation

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity

The optimal rotation of a flammable forest stand

1980 ◽  
Vol 10 (1) ◽  
pp. 30-34 ◽  
Author(s):  
D. L. Martell
Keyword(s):  
Stochastic Model ◽  
Fire Management ◽  
Jack Pine ◽  
Forest Stand ◽  
Timber Production ◽  
Forest Stands ◽  
Rotation Interval ◽  
Optimal Rotation

The author describes a stochastic model of forest stand rotation which can be used to determine the optimal planned rotation interval for flammable forest stands. The model can also be used to estimate the value of fire management activities in terms of the potential enhanced value of timber production. The use of the model is illustrated by applying it to a simplified case of jack pine (Pinusbanksiana, Lamb.) management.

STRUCTURAL AND FLORISTIC CHARACTERIZATION OF THE OULED BECHIH FOREST (ALGERIA)

2021 ◽  
Author(s):  
Touafchia Boutheyna ◽  
Kadi Zahia ◽  
Redjaimia Lilia ◽  
Rached-Kanouni Malika
Keyword(s):  
Diversity Index ◽  
Basal Area ◽  
Woody Species ◽  
Quercus Suber ◽  
Average Density ◽  
Quercus Canariensis ◽  
Rational Management ◽  
Sustainable Conservation ◽  
Total Structure

The objective of this study is the rational management of forest ecosystems for sustainable conservation of floristic biodiversity. Two types of analysis are carried out: structural analysis and analysis of the main species. A total of 22 families were identified, divided among 32 species. The dominant woody species are Quercus suber and Quercus canariensis. Fagaceae is the most represented family. The average values of species richness and Shannon diversity index are 4 ± 1.8 and 0.9 ± 0.30 species/plot respectively. The average density of woody species in the Oueld Bechih forest was 158 ± 28 tree/ha with an average basal area of 32.67 ± 0.74m²/ha. The height structure shows that trees in height classes is ≥ 6 has very high density, evidence of almost no natural regeneration. The total structure indicates that larger trees are more abundant. In effect, this work provides a database for the forest, but it represents only one facet to be considered in protecting and restoring it.

scholarly journals The effect of Broussonetia papyrifera invasion on the regeneration of selected native timber species in a tropical moist forest in Uganda

2021 ◽  
Author(s):  
Davis Mark Ssemanda ◽  
Enock Ssekuubwa
Keyword(s):  
Tropical Forests ◽  
Linear Models ◽  
Block Design ◽  
Basal Area ◽  
Timber Production ◽  
Timber Species ◽  
Production Potential ◽  
Broussonetia Papyrifera ◽  
Randomized Block Design ◽  
Moist Forest

Abstract Broussonetia papyrifera has been identified as one of the top invasive species in some African tropical forests with potentially devastating impacts on the conservation and timber production potential of the forests. This study determined the effect of B. papyrifera on the regeneration of selected native timber species in Mabira Forest Reserve, Uganda. The abundance, basal area and population structure of the timber species were compared between areas invaded and uninvaded by B. papyrifera. Employing a complete randomized block design, a total of forty plots (30 x 30 m each), and equally distributed between invaded and uninvaded areas with similar habitat conditions were surveyed. Counts of seedlings were recorded and diameter of saplings and trees measured. Generalized linear models were used to analyze the abundance, tree basal area and size class distributions of the selected species. The study revealed that the effects of B. papyrifera invasion vary depending on the growth stage and species studied. Overall, B. papyrifera invasion significantly reduced tree abundance and basal area, and suppressed the regeneration of some but not all the selected species. Our results demonstrate that if the spread of B. papyrifera is not abated, it will lower the conservation and timber production potential of tropical forests. Therefore, we call for interventions to control the spread of B. papyrifera to the uninvaded parts of the forests and halt its multiplication in invaded areas so as to enhance the regeneration and growth of timber species.

scholarly journals Algorithm for assessing forest stand productivity index using leaf area index

2019 ◽  
Vol 16 (3) ◽  
pp. 1311
Author(s):  
Faid Abdul Manan ◽  
Muhammad Buce Saleh ◽  
I Nengah Surati Jaya ◽  
Uus Saepul Mukarom
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Basal Area ◽  
Forest Stand ◽  
Productivity Index ◽  
Estimation Model ◽  
Area Index ◽  
Study Objective ◽  
Stand Productivity ◽  
Variable Combination

This paper describes a development of an algorithm for assessing stand productivity by considering the stand variables. Forest stand productivity is one of the crucial information that required to establish the business plan for unit management at the beginning of forest planning activity. The main study objective is to find out the most significant and accurate variable combination to be used for assessing the forest stand productivity, as well as to develop productivity estimation model based on leaf area index. The study found the best stand variable combination in assessing stand productivity were density of poles (X2), volume of commercial tree having diameter at breast height (dbh) 20-40 cm (X16), basal area of commercial tree of dbh >40 cm (X20) with Kappa Accuracy of 90.56% for classifying into 5 stand productivity classes. It was recognized that the examined algorithm provides excellent accuracy of 100% when the stand productivity was classified into only 3 classes. The best model for assessing the stand productivity index with leaf area index is y = 0.6214x - 0.9928 with R2= 0.71, where y is productivity index and x is leaf area index.

scholarly journals The possibility of reclamation criteria success in Indonesia: soil condition, vegetation structure and species composition

2021 ◽  
Vol 9 (1) ◽  
pp. 3201-3210
Author(s):  
Tedi Yunanto ◽  
Farisatul Amanah ◽  
Nabila Putri Wisnu
Keyword(s):  
Species Composition ◽  
Vegetation Structure ◽  
Diversity Index ◽  
Basal Area ◽  
Mineral Resources ◽  
Soil Condition ◽  
Mine Reclamation ◽  
Soil Conditions ◽  
Standard Interval ◽  
Chemical Conditions

There are two regulations for mine reclamation success in the forestry area in Indonesia, namely Minister of Forestry Regulation No. P.60/Menhut-II/2009 and Minister of Energy and Mineral Resources Decree No. 1827.K/30/MEM/2018. Both regulations rule vegetation and soil success. This study aims to analyse criteria parameters from both regulations in the mine reclamation and compare them to the surrounding secondary natural forest (SNF). This study was conducted in 6 six types of mine reclamation stand structures: 1, 4, 6, 9, 11-year-old plantation and SNF using 1 hectare of the circular plot each (total 6 ha). Soil samples were collected from 40 cm depth to analyse physical, biological and chemical conditions. Mine reclamation areas had almost similar physical, biological and chemical soil conditions with SNF. Nevertheless, due to the potential acid-forming (PAF) material from overburden, the 1-year-old plantation had pH = 3.23-3.27. The highest diversity index and the number of species and families in all reclamation areas were H’ = 1.82 (11-year-old); 14 species (9-year-old); and 11 families (9-year-old), comparing with SNF were H’ = 3.48; 67 species, and 31 families. Conversely, vegetation structure parameters in mine reclamation areas were higher than SNF (diameter at height breast (DBH; 1.3 m) = 28.42 cm; tree density = 469/ha; basal area = 35.04 m2/ha; and total height = 16.85 m). Compared to the SNF, vegetation structure and soil conditions are mostly possible for mine reclamation success. Still, species composition needs to be considered further as a standard interval to meet the criteria.

scholarly journals TREE SPECIES DIVERSITY IN A PRISTINE MONTANE FOREST PREVIOUSLY UNTOUCHED BY HUMAN ACTIVITIES IN FOJA MOUNTAINS, PAPUA, INDONESIA

REINWARDTIA ◽  
2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Asep Sadili ◽  
Kuswata Kartawinata ◽  
Herwasono Soedjito ◽  
Edy Nasriadi Sambas
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Human Activities ◽  
Diversity Index ◽  
Basal Area ◽  
Montane Forest ◽  
Tree Species Diversity ◽  
Importance Value ◽  
Montane Forests ◽  
Species Area

ADILI, A., KARTAWINATA, K., SOEDJITO, H. & SAMBAS, E. N. 2018. Tree species diversity in a pristine montane forest previously untouched by human activities in Foja Mountains, Papua, Indonesia. Reinwardtia 17(2): 133‒154. ‒‒ A study on structure and composition of the pristine montane forest previously untouched by human activities was conducted at the Foja Mountains in November 2008. We established a one-hectare plot divided into 100 subplots of 10 m × 10 m each. We enumerated all trees with DBH ≥ 10 cm which diameters were measured, heights were estimated and habitats were noted. We recorded 59 species, 42 genera and 27 families, comprising 693 trees with the total basal area (BA) of 41.35 m2/ha. The forest had lower species richness compared to those of lowland forests in Kalimantan, and Sumatra and montane forests in West Java. The Shannon-Wiener’s diversity index was 3.22. Nothofagus rubra (Importance Value, IV=47.89%) and Parinari corymbosa (IV=40.3%) were the dominant species, constituting the basis for designating the forest as the Nothofagus rubra - Parinari corymbosa association. To date, the dominance of N. rubra is unique to the Foja Mountains, as elsewhere in Papua the montane forests were dominated by N. pullei or other species. The species-area curve indicated a minimal area of 5000 m2. On the family level Fagaceae (IV=53.23%), Chrysobalanaceae (IV=40.53%) and Myristicaceae (IV=26.43%) were dominant. Verti-cally the forest consisted of four strata (A–D). In each stratum Nothofagus rubra, Platea latifolia, Parinari corymbosa and Myristica hollrungii were dominant. The diameter class distribution of Nothofagus rubra, Parinari corymbosa and Platea latifolia led us to assume that these species were regenerating well.

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