The Valuation of Thinning Efectivity Based on Increment Respond of Natural Forest Log Over Area

Efforts to increase the natural forest productivity was conducted using several ways one of which is through thinning but the effectiveness is not well known yet. The research aims to evaluate the effectiveness of the application of thinning techniques to logged-over natural forests based on the response of the stand increment. The study design was an 11-year-old logged-over natural forest stand that was carried out systematic thinning, thinning based on built trees and without treatment with a total area of 24 ha. Data collection is done by census inventory of trees with limit diameter of 10 cm per 2 years periodically. Stand conditions in the research plot varied in value range of density (419-510 stems ha-1) and the base plane (22.66-28.20 m2.ha-1) which were not too wide. The results of the calculation of the base plan of the stand shows that systematic thinning yields a larger stand increment (0.78-1.95 m2.ha-1.2th-1) compared to thinning based on built trees and without treatment. Thinning gives more responsive results for the Dipterocarp species group (the increment value is almost twice to normal) compared to non Dipterocarp. Based on the regression analysis, function of time period has correlation between 25-33% to the basal area increment. A systematic thinning technique approach that is more appropriate for increasing stand productivity.

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Algorithm for assessing forest stand productivity index using leaf area index

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v16.i3.pp1311-1319 ◽

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.

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A simple and effective approach to quantitatively characterize structural complexity

Scientific Reports ◽

10.1038/s41598-020-79334-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Gongqiao Zhang ◽

Gangying Hui ◽

Aiming Yang ◽

Zhonghua Zhao

Keyword(s):

Structural Complexity ◽

Basal Area ◽

Structural Diversity ◽

Distribution Patterns ◽

Natural Forest ◽

Random Trees ◽

Forest Communities ◽

Natural Forests ◽

Planted Forests ◽

Structural Units

AbstractThis study brings insight into interpreting forest structural diversity and explore the classification of individuals according to the distribution of the neighbours in natural forests. Natural forest communities with different latitudes and distribution patterns in China were used. Each tree and its nearest neighbours form a structural unit. Random structural units (or random trees) in natural forests were divided into different sub-types based on the uniform angle index (W). The proportions of different random structural units were analysed. (1) There are only two types of random structural units: type R1 looks similar to a dumbbell, and type R2 looks similar to a torch. These two random structural units coexist in natural forests simultaneously. (2) The proportion of type R1 is far less than that of R2, is only approximately 1/3 of all random structural units or random trees; R2 accounts for approximately 2/3. Furthermore, the proportion of basal area presents the same trend for both random structural units and random trees. R2 has approximately twice the basal area of R1. Random trees (structural units) occupy the largest part of natural forest communities in terms of quantity and basal area. Meanwhile, type R2 is the largest part of random trees (structural units). This study finds that the spatial formation mechanism of natural forest communities which is of great significance to the cultivation of planted forests.

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Opportunity cost of natural forest management in the Arenal-Huetar Norte Conservation Area, Costa Rica

10.21203/rs.3.rs-35216/v1 ◽

2020 ◽

Author(s):

Christian Zúñiga-Méndez ◽

Victor Meza-Picado ◽

Sebastian Ugalde-Alfaro ◽

Jhonny Méndez-Gamboa

Keyword(s):

Costa Rica ◽

Forest Management ◽

Opportunity Cost ◽

Natural Forest ◽

Land Uses ◽

Natural Forests ◽

Landscape Matrix ◽

Conservation Area ◽

Productive Activities ◽

Natural Forest Management

Abstract Background: Part of the success of forest conservation programs is due to the economic sustainability they can provide to owners of forest resources, and how these management mechanisms can be used within an increasingly aggressive productive landscape matrix. However, there are currently no precise or up-to-date data on the economic relationships between land uses and their respective productive activities. This study designed a model to evaluate the opportunity cost of natural forest management, taking as a reference the primary productive activities that take place within the Arenal-Huetar Norte Conservation Area, in Costa Rica. Methods: Profitability data from 24 sites in natural forests with a forest management plan approved by the State Forest Administration was used, as well as geographic and productive information on alternative land uses. Results: Based on these data, an opportunity cost map was generated which shows a marked segregation of the forests into two main areas: a) a high-opportunity cost area, located south of the study area; and b) a medium-low opportunity cost area, to the center-north of the study area. Conclusions: It is concluded that ideal areas for timber harvesting are currently restricted to places far from the market, and with low opportunity costs (ranging between ≤ $0 ha -1 year -1 and $500 ha -1 year -1 ).

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Community Structure of Dragonfly (Ordo: Odonata) in Natural Forest and Tourist Sites Petungkriyono Forest, Central Java, Indonesia

Journal of Tropical Biodiversity and Biotechnology ◽

10.22146/jtbb.67328 ◽

2021 ◽

Vol 6 (3) ◽

pp. 67328

Author(s):

Nur Apriatun Nafisah ◽

R.C.Hidayat Soesilohadi

Keyword(s):

Community Structure ◽

Tropical Rainforest ◽

Diversity Index ◽

Natural Forest ◽

Natural Forests ◽

Community Based ◽

Central Java ◽

Wiener Diversity Index ◽

Index Value ◽

Total Species

Petungkriyono forest is a tropical rainforest with high biodiversity. The increasing tourism activities in Petungkriyono lead to land conversion. Dragonfly (order Odonata) is a good bioindicator for aquatic and terrestrial. This study aimed to compare the community structure of Odonata in natural forests and tourist sites. The method of collecting imago Odonata was done by direct searching, samples were captured using sweep netting. The results showed that the dragonflies found in all locations consisted of the same family, 2 families (Gomphidae and Libellulidae) from the suborder Anisoptera and 6 families (Calopterygidae, Chlorocyphidae, Coenagrionidae, Euphaidae Platycnemididae, and Platystictidae) from the suborder Zygoptera. The total species of dragonflies found in Sokokembang were 15 species with a total of 293 individuals, Tirta Muncar 13 species of 287 individuals, Karanggondang 17 species of 276 individuals, and Curug Lawe 14 species of 242 individuals. The highest relative abundance of individuals was in the natural forest of Sokokembang is Drepanosticta spatulifera (26.28%) and in Karanggondang Vestalis luctuosa (24.64%), while in the tourist forests of Tirta Muncar and Curug Lawe were Euphaea variegata (34.84% and 28.51 %). The structure of the Odonata community is based on the Shannon-Wiener diversity index in the natural forests of Sokokembang (2.18) and Karanggondang (2.21) at the tourist sites of Tirta Muncar (1.84) and Curug Lawe (2.11). The results showed that the structure of the Odonata community based on the level of the diversity index value, evenness index, and dominance index in natural forests and tourist sites in Petungkriyono forest was not significantly different.

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Comparison of density and basal area estimation of mountain natural forests based on distance-based sampling methods in Zhejiang, China

Ecological Informatics ◽

10.1016/j.ecoinf.2021.101530 ◽

2021 ◽

pp. 101530

Author(s):

Gongqiao Zhang ◽

Hui Peng ◽

Hongmin Zhou ◽

Xinliang Ji ◽

Shusheng Zhang

Keyword(s):

Sampling Methods ◽

Basal Area ◽

Natural Forests ◽

Area Estimation

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A Multivariate Hybrid Stochastic Differential Equation Model for Whole-Stand Dynamics

Mathematics ◽

10.3390/math8122230 ◽

2020 ◽

Vol 8 (12) ◽

pp. 2230

Author(s):

Petras Rupšys ◽

Martynas Narmontas ◽

Edmundas Petrauskas

Keyword(s):

Differential Equation ◽

Stochastic Differential Equation ◽

Diffusion Processes ◽

Basal Area ◽

Equation Model ◽

Forest Stand ◽

Growth And Yield ◽

Stand Dynamics ◽

Mixed Effect ◽

Pine Tree

The growth and yield modeling of a forest stand has progressed rapidly, starting from the generalized nonlinear regression models of uneven/even-aged stands, and continuing to stochastic differential equation (SDE) models. We focus on the adaptation of the SDEs for the modeling of forest stand dynamics, and relate the tree and stand size variables to the age dimension (time). Two different types of diffusion processes are incorporated into a hybrid model in which the shortcomings of each variable types can be overcome to some extent. This paper presents the hybrid multivariate SDE regarding stand basal area and volume models in a forest stand. We estimate the fixed- and mixed-effect parameters for the multivariate hybrid stochastic differential equation using a maximum likelihood procedure. The results are illustrated using a dataset of measurements from Mountain pine tree (Pinus mugo Turra).

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Competition Indexes to Evaluate Tree Growth in a Semi-Deciduous Seasonal Forest

Floresta e Ambiente ◽

10.1590/2179-8087.010716 ◽

2019 ◽

Vol 26 (4) ◽

Author(s):

Ilvan Medeiros Lustosa Junior ◽

Renato Vinícius Oliveira Castro ◽

Ricardo de Oliveira Gaspar ◽

Juliana Baldan Costa Neves Araújo ◽

Fabiana de Gois Aquino

Keyword(s):

Tree Growth ◽

Basal Area ◽

Natural Forests ◽

Competition Index ◽

Radius Of Influence ◽

Fixed Radius ◽

The Subject

ABSTRACT Most of the studies that analyze the behavior of tree competition approach even-aged plantations. Therefore, it is possible to notice a lack of this kind of information regarding natural forests with high biodiversity. The objective of this study was to evaluate the competition in a fragment of Semi-Deciduous Seasonal Forest, according to the ecologic group, light depending and non-depending groups for all species sampled in the fragment. The Distance Independent Competition Index and Semi-Distance Independent Competition Index were applied in this study. The basal area in larger trees index, without the radius of influence, was the most efficient to analyze how the competition affects the growth of the specimens in the studied fragment. It was stated that evaluating the competition per ecologic group is more efficient. The results confirm that the forest competition cannot be determined by considering only a fixed radius of influence that embraces the neighbors and the subject tree.

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Influence of Land-Use Type on Forest Bird Community Composition in Mount Kenya Forest

International Journal of Ecology ◽

10.1155/2019/8248270 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Samuel N. Mahiga ◽

Paul Webala ◽

Mugo J. Mware ◽

Paul K. Ndang’ang’a

Keyword(s):

Land Use ◽

Species Richness ◽

Bird Community ◽

Natural Forest ◽

Forest Biodiversity ◽

Natural Forests ◽

Plantation Forest ◽

Point Counts ◽

Plantation Forests ◽

Relative Species Richness

Few studies have explored how human land uses influence and support persistence of forest biodiversity in central Kenya. In the case of the Mount Kenya ecosystem, farmlands and plantation forests are significant land-use types. Using point counts, we assessed bird communities in natural forests, plantation forests, and farmlands in the Nanyuki Forest Block, Western Mount Kenya. Bird point counts were undertaken during two sampling periods (wet and dry season). Compared to farmlands and plantation forest, natural forest had the highest overall avian species richness and relative species richness of all except one forest-dependent foraging guild (granivores) and nonforest species, which occurred frequently only on farmlands. Plantation forest had the lowest relative richness of all avian habitat and foraging guilds. Conversely, specialist forest-dependent species mainly occurred in the structurally complex remnant natural forest. Our study underscores the importance of remnant natural forests for the persistence and conservation of forest biodiversity and risks posed by replacing them with plantation forests and farmlands.

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