scholarly journals Modelling regeneration and recruitment in a tropical rain forest

1992 ◽  
Vol 22 (9) ◽  
pp. 1235-1248 ◽  
Author(s):  
Jerome K. Vanclay
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Growth Models ◽  
Basal Area ◽  
Relative Number ◽  
Site Quality ◽  
Permanent Sample Plots ◽  
Second Stage ◽  
Number Of Stems ◽  
Stand Basal Area

A two-stage model predicts the recruitment (i.e., the number of stems reaching or exceeding 10 cm DBH) of the 100 species that account for 97% of all the recruitment observed on 217 permanent sample plots in the tropical rain forest of north Queensland. The first stage predicts the probability of the occurrence of any recruitment from stand basal area and the presence of that species in the existing stand. These probabilities can be implemented stochastically, or deterministically by summing the probabilities and initiating recruitment on unity. The second stage indicates the expected amount of recruitment, given that it is known to occur, and employs stand basal area, the relative number of trees of that species in the stand, and site quality. This approach is easily implemented in growth models and planning systems.

scholarly journals EFFECT OF TIMBER HARVESTING ON DENSITY AND BASAL AREA OF LECYTHIDACEAE SPECIES IN THE EASTERN AMAZON

FLORESTA ◽  
2013 ◽  
Vol 44 (2) ◽  
pp. 229 ◽  
Author(s):  
Pamella Carolline Marques dos Reis ◽  
Leonardo Pequeno Reis ◽  
Ademir Roberto Ruschel ◽  
José Natalino Macedo Silva ◽  
João Olegário Pereira de Carvalho ◽  
...  
Keyword(s):  
Forest Management ◽  
Forest Dynamics ◽  
Natural Regeneration ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Positive Response ◽  
Basal Area ◽  
Timber Harvesting ◽  
Amazon Forest ◽  
Permanent Sample Plots

Dynamics of Lecythidaceae species were evaluated 13 years after logging in a dense tropical rain forest located in the municipality of Moju, Pará (02º 08’ 14’’ and 02º 12’ 26” S; 48º 47’ 34”S and 48º 48’ 14” W - SAD 69). Two hundred ha out of a 1,050 ha forest area were selectively logged for timber (23 m3 ha-1 harvested from 25 species) in 1997. Twenty-two permanent sample plots of 0.5 ha (11 ha sample area) were established and all trees with DBH ≥ 10 cm were measured and identified in 1995, 1998 and 2010. Density (trees ha-1) and basal area (m2 ha-1) of the species were evaluated in the three occasions. The opening of canopy caused by logging reduced the density and basal area of five species, but produced a positive response in nine species, boosting their natural regeneration and allowing the ingrowth of one species that was not present in the studied area in the beginning.Keywords: Forest dynamics; Tauari; forest management; Amazon Forest. ResumoEfeito da exploração de madeiras na densidade e área basal de espécies de Lecythidaceae no leste da Amazônia. Analisou-se a dinâmica de espécies de Lecythidaceae 13 anos após a exploração madeireira, em uma Floresta Ombrófila Densa no município de Moju, Pará (02º 08’ 14’’ e 02º 12’ 26” S; 48º 47’ 34”S e 48º 48’ 14” W - SAD 69). De uma área de floresta de 1.050 ha, foram selecionados 200 ha para exploração seletiva, em 1997, de 25 espécies comerciais madeireiras (intensidade de 23 m3 ha-1). Foram alocadas 22 parcelas permanentes de 0,5 ha, totalizando 11 ha amostrais, onde foram medidas todas as árvores com DAP≥ 10 cm, nos anos de 1995, 1998 e 2010. Analisou-se a densidade (árvores ha-1) e área basal (m2 ha-1) das espécies, nas três ocasiões. A abertura do dossel causada pela exploração reduziu a densidade e a área basal de cinco espécies, porém produziu impacto positivo em nove espécies, estimulando a sua regeneração natural e, inclusive, proporcionando o ingresso de uma espécie que não estava presente na área monitoradaPalavras-chave: Dinâmica da floresta; Tauarí; manejo florestal; Floresta Amazônica.

scholarly journals EFEITO DA EXPLORAÇÃO DE IMPACTO REDUZIDO EM ALGUMAS ESPÉCIES DE SAPOTACEAE NO LESTE DA AMAZÔNIA

FLORESTA ◽  
2013 ◽  
Vol 43 (3) ◽  
pp. 395 ◽  
Author(s):  
Leonardo Pequeno Reis ◽  
José Natalino Macedo Silva ◽  
Pamella Carolline Marques Dos Reis ◽  
João Olegário Pereira de Carvalho ◽  
Waldenei Travassos de Queiroz ◽  
...  
Keyword(s):  
Rain Forest ◽  
Basal Area ◽  
Tree Density ◽  
The Other ◽  
Permanent Sample Plots ◽  
Structure And Dynamics ◽  
The Family ◽  
Commercial Species ◽  
Three New Species ◽  
Reduced Impact Logging

Avaliou-se o efeito da exploração de madeira, realizada em 1997, na estrutura e dinâmica de algumas espécies de Sapotaceae em uma Floresta Ombrófila Densa, no município de Moju, Pará (02º12’26”S e 48º48’14”W). De uma área de floresta de 1.050 ha, foram selecionados 200 hapara exploração seletiva de intensidade de 23 m3.ha-1. Nessa área, foram alocadas 22 parcelas permanentes de 0,5 ha, totalizando 11 ha amostrais, onde foram medidas todas as árvores com DAP ≥10 cm, nos anos de 1995 (antes da exploração), 1998 e 2010 (após exploração). Os parâmetros avaliados foram densidade (Da) e área basal (m2.ha-1). No período de 1995 a 2010, Sapotaceae apresentou uma redução significativa de 7,7% na densidade (p = 0,0147) e aumento na dominância em 1,4% (p = 0,7851). Nesse mesmo período, observou-se redução da densidade e dominância para Pouteria laurifolia (Gomes) Radlk. (66,7 e 50,6%), Pouteria macrocarpa (Mart.) D. Dietr. (25 e 29,4%), Micropholis acutangula (Ducke) Eyma (20 e 11%), Manilkara huberi (Ducke) A. Chev. (16,4 e 17,7%) e Manilkara paraensis (Huber) Standl. (12,5 e 31,4%). A espécie com maior valor comercial, M. huberi, não mostrou recuperação nesse parâmetro, porém houve ingresso de três novas espécies na população de Sapotaceae estudada.AbstractEffect of reduced impact logging in some sapotaceae species in the eastern amazon. Effect of logging, held in 1997, on structure and dynamics of some Sapotaceae species were evaluated in a dense tropical rain forest located in the municipality of Moju, Pará (02º 12’ 26” S e 48º 48’ 14” W). Two hundred ha out of 1,050 ha forest area were selectively logged for timber (23 m3ha-1 logging intensity) in 1997.Twenty-two 0.5 ha permanent sample plots (11 ha sample) were established and all trees with dbh ≥ 10 cm were identified and measured for dbh in 1995 (before logging), 1998 and 2010 (after logging). Parameters evaluated were Density (De) and Basal area (G-m2 ha-1). Sapotaceae presented a significant reduction of 7.7% on tree density (p=0.0147), and an dominance increase of 1.4% (p=0.7851). In the same period, decreases in density and basal area were observed to Pouteria laurifolia (Gomes) Radlk. (66.7 and 50.6%), Pouteria macrocarpa (Mart.) D. Dietr. (25 and 29.4%), Micropholis acutangula (Ducke) Eyma (20 and 11%), Manilkara huberi (Ducke) A. Chev. (16.4 and 17.7%) and Manilkara paraensis (Huber) Standl. (12.5 and 31.4%). The main commercial species M. Huberi did not recover its original density. On the other hand, three new species of the family were recorded in the focused period.Keywords: Forest management; Pouteria; Manilkara; Amazonian Forest.

scholarly journals Stand growth model using volume increment/basal area ratios

2008 ◽  
Vol 54 (No. 3) ◽  
pp. 102-108 ◽  
Author(s):  
J. Martínez Pastur G ◽  
M. Cellini J ◽  
V. Lencinas M ◽  
L. Peri P
Keyword(s):  
Simple Model ◽  
Growth Models ◽  
Basal Area ◽  
Site Quality ◽  
Stand Age ◽  
Full Density ◽  
Nothofagus Pumilio ◽  
Stand Growth ◽  
Mean Error ◽  
Volume Increment

Estimation of stand growth is crucial for forest planning. Estimations were usually done using fixed values, and recently growth equations have been used. An alternative is through stand growth models. The objective was to develop a simple model for<I> Nothofagus pumilio</I> stands with full density along site quality and age gradients. The sample was obtained from 125 stands. Data on forest structure and samples for tree-ring measurement were taken in all trees to estimate growths using biometric models previously developed. The growth values of each plot during the last twenty years were calculated to fit the model, using the ratio of total volume increment/basal area as an independent variable. The developed model gives a ratio between stand volume increment and basal area (m/year) in relation to the site quality and stand age. The statistics (<I>r</I><sup>2</sup> = 0.819, mean error = 0.019, absolute mean error = 0.033), residual analysis and biological performance were satisfactory. The obtained stand growths varied between 1 and 20 m<sup>3</sup>/ha/year. This simple model allowed to estimate growth values at a stand level from easy field measurements from forest inventories.

Tree population changes in treated rain forest at Omo Forest Reserve, south-western Nigeria

1987 ◽  
Vol 3 (4) ◽  
pp. 291-313 ◽  
Author(s):  
D. U. U. Okali ◽  
B. A. Ola-Adams
Keyword(s):  
Rain Forest ◽  
Forest Biomass ◽  
Basal Area ◽  
Walsh System ◽  
Relative Distribution ◽  
Annual Increment ◽  
Forest Reserve ◽  
Number Of Species ◽  
Canopy Opening ◽  
Number Of Stems

ABSTRACTA review of previous evaluations of long-term changes in treated Nigerian rain forest is presented, to show that these studies have concentrated on economic species with little consideration of other species, or of forest biomass and structure.We examine regeneration and successional patterns in Omo Forest Reserve by comparing enumeration data taken before (1952) and after (1981) treatment of the forest by selective canopy opening and climber-cutting (Plot A), or clear-felling and burning (Walsh system) (Plot C).Before treatment, about 50 species in 25 families were found of stems ≥10 cm dbh, in 4.05 ha of the forest, the Euphorbiaceae contributing the greatest number of species while the medium-sized trees Diospyros alboflavescens (Ebenaceae) and Strombosia pustulata (Olacaceae) contributed more than 40% of the stems.Twenty-eight years after treatment (1981) the number of species and families remained similar to those in 1952, although smaller areas (0.75 ha) were enumerated; the treated plots were, however, dominated by early succession species such as Macaranga barteri, Musanga cecropioides, Cleistopholis patens, Funtumia elastica and Fagara macrophylla, and lacked an abundance of the ‘economic’ species that treatment had been expected to induce; the medium-sized trees that were dominant in 1952 were still abundant in Plot A but not in Plot C.For stems ≥ 30 cm dbh tree diversity (reciprocal of Simpson's index) was highest (15.7) in a 1952 plot and least (4.8) in the clear-felled plot enumerated in 1981; diversity of the 1952 plots, however, fell markedly to values lower than those for the 1981 plots when computation was based on all stems ≥10 cm dbh, presumably because of increase in abundance of small-stemmed species like Diospyros spp., Strombosia sp. and Rinorea sp., each represented by a large number of stems.Basal area was greatest (29.6 m2 ha−1) in the 1952 plots and least (12.7 m2 ha−1) in the clear-felled plots enumerated in 1981, but the relative distribution of basal area and number of stems in size-classes was similar in all the plots.Mean annual increment, computed by dividing the mean diameter (7.50 cm) of the stems in the clear-felled plots by the number of years (28) over which they had grown, was 0.27 cm.Nauclea diderrichii dominated the seedling regeneration from the first year after clear-felling and burning (1954) till the sixth year (1960), when seedlings of the Meliaceae entered the regeneration list and overall seedling density was 395 per hectare.Among the plots assessed in 1981, the standing crop was greatest in an untreated Control plot (229.6 t ha−1) followed by Plot A (159.7 t ha−1) and Plot C (91.1 t ha7−1), but the relative allocation of biomass to stem, branch, leaf, root and fruit fractions was comparable for all plots.The data are discussed in relation to other Nigerian forest studies and it is suggested that the main qualitative features of structural organization and the species composition of the top canopy synusia of mature secondary rain forest may be determined quite early in the development of the stand.

A review of stand basal area growth models

2007 ◽  
Vol 9 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Hong-gang Sun ◽  
Jian-guo Zhang ◽  
Ai-guo Duan ◽  
Cai-yun He
Keyword(s):  
Growth Models ◽  
Basal Area ◽  
Basal Area Growth ◽  
Area Growth ◽  
Stand Basal Area

scholarly journals Analyzing ingrowth using zero-inflated negative binomial models

Silva Fennica ◽  
2020 ◽  
Vol 54 (4) ◽  
Author(s):  
Juha Lappi ◽  
Timo Pukkala
Keyword(s):  
Fixed Effects ◽  
Negative Binomial ◽  
Basal Area ◽  
National Forest Inventory ◽  
Mixed Effects ◽  
Low Fertility ◽  
Mixed Effects Models ◽  
Permanent Sample Plots ◽  
Temperature Sum ◽  
Stand Basal Area

Ingrowth is an important element of stand dynamics in several silvicultural systems, especially in continuous cover forestry. Earlier predictive models for ingrowth in Finnish forests are few and not based on up-to-date statistical methods. Ingrowth is here defined as the number of trees over 1.3 m entering a plot. This study developed new ingrowth models for Scots pine ( L.), (Picea abies (L.) H. Karst.) and birch ( Roth and Ehrh.) using data from the permanent sample plots of the Finnish national forest inventory. The data were over-dispersed compared to a Poisson process and had many zeros. Therefore, a zero-inflated negative binomial model was used. The total and species-specific stand basal areas, temperature sum and fertility class were used as predictors in the ingrowth models. Both fixed-effects and mixed-effects models were fitted. The mixed-effects model versions included random plot effects. The mixed-effects models had larger likelihoods but provided biased predictions. Also censored prediction was considered where only a certain maximum number of ingrowth trees were accepted for a plot. The models predicted most pine ingrowth in pine-dominated stands on sub-xeric and xeric sites where stand basal area was low. The predicted amount of spruce ingrowth was maximized when the basal area of spruce was 13 m ha. Increasing temperature sum increased spruce ingrowth. Predicted birch ingrowth decreased with increasing stand basal area and towards low fertility classes. An admixture of pine increased the predicted amount of spruce ingrowth.Pinus sylvestrisNorway spruceBetula pendulaB. pubescens2–1

Nonlinear Models for Stand Table Projection in Northern Hardwood Stands

1974 ◽  
Vol 4 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Alan R. Ek
Keyword(s):  
Nonlinear Models ◽  
Basal Area ◽  
Growth Period ◽  
Size Class ◽  
Diameter Class ◽  
Site Class ◽  
Northern Hardwood ◽  
Number Of Stems ◽  
A Site ◽  
Stand Basal Area

Nonlinear equation models were developed for prediction of periodic ingrowth, mortality, and survivor growth by 2-in. (5.1-cm) diameter classes in northern hardwood stands. Equations were constructed using 5 year growth records on 132 plots from stands with a broad range of age and size class distributions. The model for number of ingrowth trees in the smallest diameter class measured was [Formula: see text] where G and N are initial stand basal area and number of trees, respectively, on a per acre basis and the bi's are constants. Mortality in a diameter class expressed as trees per acre was described by the model [Formula: see text] where g and n indicate initial basal area and number of trees in a specified diameter class. Survivor growth was described by prediction of the number of trees in a class which grow into the next larger size class during the growth period. The model for the number of stems moving up was [Formula: see text] where S is a site class term. Considerations in the formulation of the models and a discussion of their utility and limitations are also presented.

scholarly journals The Fate of a Tropical Rainforest in Nigeria: Abeku Sector of Omo Forest Reserve

2013 ◽  
Vol 6 (2) ◽  
pp. 116-130 ◽  
Keyword(s):  
Basal Area ◽  
Floristic Composition ◽  
Abundant Species ◽  
Diversity Indices ◽  
Forest Monitoring ◽  
Forest Reserve ◽  
Mean Values ◽  
Permanent Sample Plots ◽  
Large Trees ◽  
Number Of Stems

Sixteen permanent sample plots of one hectare each, established in 1985 at Abeku sector of Omo Forest Reserve, South west Nigeria by the European Economic Community/ Nigeria Federal Government (High Forest Monitoring Plots Project) (EEC/HFMPP) were used for this study. The plots were re-enumerated in 1987. Further assessment took place in 1997 and 2000 respectively for the purpose of assessing the floristic characteristics of the plots. The present study aims at assessing the floristic composition during the sampling years. Out of the original 16 plots only eleven and nine plots were available for assessment in 1997 and 2000 respectively. The remaining plots had been converted to plantations of arable and cash crops. The numbers of tree species encountered were 98, 109, 95 and 71 for 1985, 1987, 1997 and 2000 enumerations respectively. Also 28,31, 29 and 23 families were encountered in 1985, 1987, 1997 and 2000 respectively. In terms of density, basal area and spread, the ten most abundant species are Diospyros iturensis (Plant nomenclature follows Hutchinson and Dalziel (1954-72); Keay (1989) and Lowe and Soladoye (1990)), (DIAL),Tabernaemontana pachysiphon (TAPA), Octolobus angustatus (OLAN), Strombosia pustulata (SBPU), Diospyros dendo (DIDE), Diospyros suaveolens (DISU), Drypetes gossweileri (DRGO), Rothmania hispida (ROHI), Hunteria unbellata (HUUM) and Anthonotha aubryanum (ASAU) and the six most prominent families are Ebenaceae, Apocynaceae, Euphorbiaceae, Sterculiaceae, Olacaceae and Rubiaceae .Mean number of stems per hectare ranges from 400.44 to 1134.0 for the small trees (5-20cm dbh); 89.78 to 174.25 for the medium trees (20-40cm dbh) and 8.33 to 17.06 for the large trees (> 40cm dbh) Mean basal area per hectare ranges from 4.94m2 to 8.81m2 for the small trees, 5.4m2 to 9.63m2 for the medium trees and 4.64m2 to 9.04m2 for the large trees. Inverse of Simpson diversity indices range between 15.1 to 16.27 for the small tree, 13.43 to 16.37 for the medium trees and 23.44 to 26.34 for the large trees. The highest mean values per hectare of these parameters were found in 1987 enumeration, while the least values were found in the year 2000 enumeration. This variability may not be due only to the number of plots available for enumeration alone, but also as a result of poaching in the remaining plots before the 2000 enumeration. The study recommends that conscious efforts should be made to protect and maintained the permanent sample plots not only to reduce the possibility of encroachment but also to achieve the objective for which they were established which was to elucidate the dynamics and growth pattern of the natural rainforest. There is also a need for international assistance to achieve this.

Effects of planting density and site quality on mean tree size and total stand growth of Eucalyptus globulus plantations

2013 ◽  
Vol 43 (9) ◽  
pp. 846-851 ◽  
Author(s):  
David I. Forrester ◽  
John C. Wiedemann ◽  
Robert I. Forrester ◽  
Thomas G. Baker
Keyword(s):  
Eucalyptus Globulus ◽  
Basal Area ◽  
Tree Size ◽  
Planting Density ◽  
Site Quality ◽  
Individual Tree ◽  
Quality Of Products ◽  
Stand Basal Area

The choice of planting density is a primary silvicultural decision in plantation management which considers the trade-off between individual tree size and total stand production, affecting the type, quantity and quality of products throughout the rotation. Trends in size and production with planting density are generally well known, however, less so is the interacting effect of site quality. Consequently, a case study in which basal area and basal area growth of Eucalyptus globulus Labill. plantations on five site qualities (122–435 m3·ha−1) planted at six densities (625 trees·ha−1, 4 m × 4 m; 833 trees·ha−1, 3 m × 4 m; 1000 trees·ha−1, 4 m × 2.5 m; 1250 trees·ha−1, 4 m × 2 m; 1667 trees·ha−1, 3 m × 2 m; and 2000 trees·ha−1, 3 m × 1.75 m) were used to investigate this interaction. As expected, both mean tree diameter of the whole stand and the basal area of the largest diameter 200 trees·ha−1 (D200 trees) were higher at lower planting densities, whereas whole stand basal area was greater at higher planting densities. However, there were no significant (P > 0.32) interactions between planting density and site quality for D200 or stand basal area, which contrasts with thinning responses in similar stands. This simplifies management considerations and suggests that trials at a given site quality may provide useful information about responses to planting density at other site qualities for the studied species.

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