A simple and effective approach to quantitatively characterize structural complexity

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

Journal of Sylva Indonesiana ◽

10.32734/jsi.v3i02.4291 ◽

2020 ◽

Vol 3 (02) ◽

pp. 87-96

Author(s):

Farida Herry Susanty

Keyword(s):

Basal Area ◽

Species Group ◽

Forest Stand ◽

Natural Forest ◽

Natural Forests ◽

Base Plane ◽

Stand Productivity ◽

Time Period ◽

Value Range ◽

Stand Conditions

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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Response of small mammals to alternative stand structures in the mixed-conifer forest of northeastern CaliforniaThis article is one of a selection of papers from the Special Forum on Ecological Studies in Interior Ponderosa Pine — First Findings from Blacks Mountain Interdisciplinary Research.

Canadian Journal of Forest Research ◽

10.1139/x07-239 ◽

2008 ◽

Vol 38 (5) ◽

pp. 943-955 ◽

Cited By ~ 6

Author(s):

Chris C. Maguire ◽

Douglas A. Maguire ◽

Tom E. Manning ◽

Sean M. Garber ◽

Martin W. Ritchie

Keyword(s):

Small Mammals ◽

Ponderosa Pine ◽

Structural Complexity ◽

Basal Area ◽

Stand Density ◽

Structural Diversity ◽

Conifer Forest ◽

Spermophilus Lateralis ◽

Mixed Conifer Forest ◽

Tamias Amoenus

A common, but largely untested, strategy for maintaining forest biodiversity is to enhance stand structural complexity. A silvicultural experiment was implemented from 1996 to 1998 at Blacks Mountain Experimental Forest, California, to test the efficacy of two levels of structural diversity (high versus low) and two levels of prescribed underburning (burn versus no burn) for maintaining or restoring biodiversity. Small mammals were trapped and tagged in experimental units for 2 noncontiguous weeks in fall 2003 and 2004. Total number of captures and number of captured individuals varied by year (P < 0.002). No treatment effects were detected for all species lumped together or for the three most frequent species analyzed separately ( Tamias amoenus J.A. Allen, 1890, Peromyscus maniculatus (Wagner, 1845), and Spermophilus lateralis (Say, 1823)), with the exception that T. amoenus was captured more often in burned units in 2004 (P = 0.004 for year × burn interaction). Mixed-effects regression models indicated that the number of captures and captured individuals of T. amoenus and P. maniculatus decreased with increasing residual basal area of overstory trees, but opposite results were obtained for S. lateralis. After accounting for residual stand density differences, T. amoenus was captured more frequently in units of low structural diversity and S. lateralis in units of high structural diversity.

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Langfristige Entwicklung von zwei Waldgesellschaften im Białowieża-Urwald

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2008.0080 ◽

2008 ◽

Vol 159 (4) ◽

pp. 80-90 ◽

Cited By ~ 3

Author(s):

Bogdan Brzeziecki ◽

Feliks Eugeniusz Bernadzki

Keyword(s):

Species Composition ◽

Tree Species ◽

Stand Structure ◽

Temporal Dynamics ◽

Structural Parameters ◽

Forest Communities ◽

Natural Forests ◽

Tree Species Composition ◽

Strong Trend ◽

Long Term Study

The results of a long-term study on the natural forest dynamics of two forest communities on one sample plot within the Białowieża National Park in Poland are presented. The two investigated forest communities consist of the Pino-Quercetum and the Tilio-Carpinetum type with the major tree species Pinus sylvestris, Picea abies, Betula sp., Quercus robur, Tilia cordata and Carpinus betulus. The results reveal strong temporal dynamics of both forest communities since 1936 in terms of tree species composition and of general stand structure. The four major tree species Scots pine, birch, English oak and Norway spruce, which were dominant until 1936, have gradually been replaced by lime and hornbeam. At the same time, the analysis of structural parameters indicates a strong trend towards a homogenization of the vertical stand structure. Possible causes for these dynamics may be changes in sylviculture, climate change and atmospheric deposition. Based on the altered tree species composition it can be concluded that a simple ≪copying≫ (mimicking) of the processes taking place in natural forests may not guarantee the conservation of the multifunctional character of the respective forests.

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The structural complexity index SCI is useful for quantifying structural diversity of Estonian hemiboreal forests

Forest Ecology and Management ◽

10.1016/j.foreco.2021.119093 ◽

2021 ◽

Vol 490 ◽

pp. 119093

Author(s):

Eneli Põldveer ◽

Aleksei Potapov ◽

Henn Korjus ◽

Andres Kiviste ◽

John A. Stanturf ◽

...

Keyword(s):

Structural Complexity ◽

Structural Diversity ◽

Complexity Index

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Quantifying Understory Complexity in Unmanaged Forests Using TLS and Identifying Some of Its Major Drivers

Remote Sensing ◽

10.3390/rs13081513 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1513

Author(s):

Dominik Seidel ◽

Peter Annighöfer ◽

Christian Ammer ◽

Martin Ehbrecht ◽

Katharina Willim ◽

...

Keyword(s):

Laser Scanning ◽

Structural Equation Models ◽

Light Availability ◽

Structural Complexity ◽

Basal Area ◽

Ecosystem Functions ◽

Canopy Openness ◽

Seasonal Precipitation ◽

Wide Range ◽

Precipitation And Temperature

The structural complexity of the understory layer of forests or shrub layer vegetation in open shrublands affects many ecosystem functions and services provided by these ecosystems. We investigated how the basal area of the overstory layer, annual and seasonal precipitation, annual mean temperature, as well as light availability affect the structural complexity of the understory layer along a gradient from closed forests to open shrubland with only scattered trees. Using terrestrial laser scanning data and the understory complexity index (UCI), we measured the structural complexity of sites across a wide range of precipitation and temperature, also covering a gradient in light availability and basal area. We found significant relationships between the UCI and tree basal area as well as canopy openness. Structural equation models (SEMs) confirmed significant direct effects of seasonal precipitation on the UCI without mediation through basal area or canopy openness. However, annual precipitation and temperature effects on the UCI are mediated through canopy openness and basal area, respectively. Understory complexity is, despite clear dependencies on the available light and overall stand density, significantly and directly driven by climatic parameters, particularly the amount of precipitation during the driest month.

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Restoration of floral diversity through plantations on abandoned agricultural land

Canadian Journal of Forest Research ◽

10.1139/x06-021 ◽

2006 ◽

Vol 36 (5) ◽

pp. 1218-1235 ◽

Cited By ~ 24

Author(s):

Steven G Newmaster ◽

F Wayne Bell ◽

Christopher R Roosenboom ◽

Heather A Cole ◽

William D Towill

Keyword(s):

Plant Diversity ◽

Tree Species ◽

Agricultural Land ◽

Structural Diversity ◽

Geographic Region ◽

Natural Forests ◽

Community Interactions ◽

Long Term Study ◽

Floral Diversity ◽

The Impact

Plantations have been claimed to be "monocultures", or "biological deserts". We investigated these claims in the context of a long-term study on plant diversity within plantations with different indigenous tree species, spacings, and soil types that were compared with 410 native stands. Soil type had no influence on plantation species diversity or abundance, and wider spacing resulted in higher richness, lower woody plant abundance, slightly higher cover of herbaceous plants, and large increases in cryptogam cover. We also found a canopy species × spacing interaction effect, where the impact of increased spacing on understory vegetation was more pronounced in spruce than in pine plantations. The dynamic community interactions among species of feathermoss appear to be in response to the physical impediment from varying amounts of needle rain from the different tree species. High light interception and needle fall were negatively correlated with understory plant diversity, as was lack of structural diversity. This study indicates that through afforestation efforts agricultural lands can be restored to productive forests that can harbour nearly one-half of the plant species found in equivalent natural forests within the same geographic region in as little as 50 years. We recommend applying afforestation using indigenous conifer species as a first step towards rehabilitating conifer forests that have been converted to agriculture and subsequently abandoned.

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Structural diversity of forest communities on Baihuashan Mountain, Beijing

Frontiers of Forestry in China ◽

10.1007/s11461-008-0034-7 ◽

2008 ◽

Vol 3 (2) ◽

pp. 213-218

Author(s):

Jingming Zheng ◽

Xiuhai Zhao ◽

Chunyu Zhang

Keyword(s):

Structural Diversity ◽

Forest Communities

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Opportunities for winter prescribed burning in mixed conifer plantations of the Sierra Nevada

Fire Ecology ◽

10.1186/s42408-021-00120-5 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Robert A. York ◽

Jacob Levine ◽

Kane Russell ◽

Joseph Restaino

Keyword(s):

Sierra Nevada ◽

Pinus Ponderosa ◽

Prescribed Burning ◽

Winter Season ◽

Basal Area ◽

Weather Conditions ◽

Shrub Cover ◽

Mixed Conifer ◽

Planted Forests ◽

Conifer Plantations

Abstract Background Young, planted forests are particularly vulnerable to wildfire. High severity effects in planted forests translate to the loss of previous reforestation investments and the loss of future ecosystem service gains. We conducted prescribed burns in three ~35-year-old mixed conifer plantations that had previously been masticated and thinned during February in order to demonstrate the effectiveness of winter burning, which is not common in the Sierra Nevada, California. Results On average, 59% of fine fuels were consumed and the fires reduced shrub cover by 94%. The average percent of crown volume that was damaged was 25%, with no mortality observed in overstory trees 1 year following the fires. A plot level analysis of the factors of fire effects did not find strong predictors of fuel consumption. Shrub cover was reduced dramatically, regardless of the specific structure that existed in plots. We found a positive relationship between crown damage and the two variables of Pinus ponderosa relative basal area and shrub cover. But these were not particularly strong predictors. An analysis of the weather conditions that have occurred at this site over the past 20 years indicated that there have consistently been opportunities to conduct winter burns. On average, 12 days per winter were feasible for burning using our criteria. Windows of time are short, typically 1 or 2 days, and may occur at any time during the winter season. Conclusions This study demonstrates that winter burning can be an important piece of broader strategies to reduce wildfire severity in the Sierra Nevada. Preparing forest structures so that they can be more feasible to burn and also preparing burn programs so that they can be nimble enough to burn opportunistically during short windows are key strategies. Both small landowners and large agencies may be able to explore winter burning opportunities to reduce wildfire severity.

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HEAT SECURITY AND THERMAL REGIME OF SOME TYPES OF NATURAL FOREST COMMUNITIES (AREA OF WIDE-DECIDUAL-CONIFEROUS FORESTS OF THE SOUTH URALS)

ÈKOBIOTEH ◽

10.31163/2618-964x-2020-3-3-429-434 ◽

2020 ◽

Vol 3 (3) ◽

pp. 429-434

Author(s):

Yu.P. Gorichev ◽

◽

A.N. Davydychev ◽

I.R. Yusupov ◽

A.Yu. Kulagin ◽

...

Keyword(s):

Thermal Regime ◽

Heat Supply ◽

Southern Urals ◽

Natural Forest ◽

Coniferous Forests ◽

South Urals ◽

Forest Communities ◽

The South ◽

The Southern Urals

The data of microclimatic observations carried out in the area of broad-leaved-coniferous forests of the Southern Urals are presented. The parameters of heat supply and thermal regime of some types of primary plantations are established.

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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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