scholarly journals Post-harvesting natural regeneration of Theobroma subincanum Mart. (Cupuí) (Malvaceae) inside and around logging gaps

Interação ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 413-428
Author(s):  
Nisângela Severino Lopes Costa ◽  
Fernando Cristovam da Silva Jardim ◽  
Raphael Lobato Prado Neves ◽  
Gustavo Schwartz ◽  
Luiz Fernandes Silva Dionisio
Keyword(s):  
Natural Regeneration ◽  
Recruitment Rate ◽  
Selective Logging ◽  
Medium Size ◽  
Light Conditions ◽  
Period 2 ◽  
Competition For Light ◽  
Cardinal Directions ◽  
Post Harvesting ◽  
Lower Luminosity

The natural regeneration dynamics of Theobroma subincanum Mart. (Malvaceae) around canopy gaps created by tree felling due to selective logging was assessed. For that, an experiment located in the Experimental Field of Embrapa Eastern Amazon in Moju municipality, PA, Brazil was carried out. Nine logging gaps were selected, and four strips of 10 m x 50 m were installed in each of these gaps following the cardinal directions. These plots were split in five 10 m x 10 m plots numbered from 1 to 5 from the gap’s border toward the forest. In plots 1, 3, and 5 and in the gap’s center 2 m x 2 m plots were installed to monitor individuals ≥ 10 cm in height and < 5 cm in DBH. In most of the variation factors analized, Theobroma subincanum presented higher recruitment rate in period 1 (1998-2000), since the competition for light were less intense. In period 2 (2000-2010), under a possible lower luminosity and higher competition, RR was lower for all factors analyzed. In relation to gap size, T. subincanum presented the best results in RR around medium size gaps. The distance of 20 m in relation to the gap center, with intermediary sunlight condititions, T. subincanum presented higher RR. The population of T. subincanum had better performance under intermediate light conditions.

scholarly journals Natural regeneration in logging gaps of different sizes in Subri River Forest Reserve (Ghana)

2022 ◽  
Author(s):  
Maame Esi Hammond ◽  
Radek Pokorný ◽  
Simon Abugre ◽  
Augustine Gyedu
Keyword(s):  
Tree Species ◽  
Natural Regeneration ◽  
Conservation Status ◽  
Selective Logging ◽  
Medium Size ◽  
Similar Species ◽  
Timber Species ◽  
Forest Reserve ◽  
Strict Adherence ◽  
Large Size

AbstractSubri River Forest Reserve (SR) is the most extensive forest area in Ghana with an accompanying rich floral species. Over the years, logging from both legally prescribed and illegal operations remain the predominant forest disturbance in SR. Gap creation following logging is crucial in determining tree species composition and diversity. Hence, the study evaluated the composition and diversity of naturally regenerated tree species in logging gaps of different sizes and, again examined the roles of these tree species in fulfilling the economic and ecological agenda of sustainable forest management after logging in SR. Twelve gaps were randomly selected: 4 each were grouped into small size (≤ 200 m2), medium size (201–300 m2), and large size (≥ 300 m2). Data were gathered from 1 m2 circular area at gap centres and repeatedly inside 1 m width strip along 20 m individual N-S-E-W transects. Species diversity differed significantly between gap sizes. Higher diversity indices were measured in large size gaps. Gap sizes shared similar species. There were significant differences among various height groupings of tree species across all three gap sizes. Pioneers preferred medium to large size gaps, while shade-tolerant tree species preferred small size gaps for their abundance. Vulnerable and Lower Risk Near Threatened tree species under Conservation Status and, Premium and Commercial tree species under Utilisation Status preferred small size gaps for their proliferation and conservation. Therefore, we recommend the single tree-based selective logging for ensuring creations of small to medium size (200–300 m2) gaps through adjustments to the logging permit process, revision of Allocation Quota Permit, strict adherence to the 40-year polycyclic selection system, along with more dedicated enforcement and monitoring. Changes along these protocols would tremendously facilitate natural regeneration of different suites of timber species resulting in the improvement of the overall biodiversity conservation associated with the forest, more sustainable forest harvests and more income to those who receive permits.

scholarly journals The influence of fencing on seedling establishment during reforestation of oak stands: a comparison of artificial and natural regeneration techniques including costs

2021 ◽  
Author(s):  
Magnus Löf ◽  
Julien Barrere ◽  
Mattias Engman ◽  
Linda K. Petersson ◽  
Adrian Villalobos
Keyword(s):  
Natural Regeneration ◽  
Recruitment Rate ◽  
Direct Seeding ◽  
Vegetation Control ◽  
Efficient Regeneration ◽  
Temperate Europe ◽  
Cost Efficient ◽  
Positive Effect ◽  
Establishment Rate ◽  
Block Experiment

AbstractIn temperate Europe, oak-dominated forests are widespread, supporting high biodiversity and providing important ecosystem services. Insufficient natural regeneration has, however, been a concern for over a century. The objective of this study was to gain insights into differences in regeneration success using artificial and natural regeneration techniques for reforestation of oak (Quercus robur L.) stands. We monitored seedlings following planting, direct seeding and natural regeneration over five years in a randomized block experiment in southern Sweden with fenced and non-fenced plots. Fencing had a strong positive effect on height growth, especially for planted seedlings that were taller than the other seedlings and more frequently browsed in non-fenced plots. In contrast, there was little effect of fencing on survival, establishment rate and recruitment rate of seedlings. Due to aboveground damage on seedlings from voles, protection of acorns did not improve establishment rate following direct seeding. Under current circumstances at the site with a sparse shelterwood of old oaks, we conclude that natural regeneration was the most cost-efficient regeneration method. It resulted in the most seedlings at the lowest cost. However, regeneration success was heavily influenced by interference from herbaceous vegetation. With a small additional investment in vegetation control, the results might have been improved for planting and direct seeding.

scholarly journals Yew (Taxus baccata L.) population dynamics in the Iberian Mediterranean Mountains: natural regeneration and expansion in East Central System (Spain)

2020 ◽  
Vol 29 (1) ◽  
pp. eSC03
Author(s):  
Rodrigo Balaguer-Romano ◽  
Helios Sainz-Ollero ◽  
Fernando Vasco-Encuentra
Keyword(s):  
Natural Regeneration ◽  
Age Groups ◽  
Woody Species ◽  
Recruitment Rate ◽  
Mountain Range ◽  
Taxus Baccata ◽  
Central System ◽  
Regeneration Rate ◽  
East Central ◽  
Mediterranean Mountains

Aim of study: To evaluate demographical dynamics of yew populations in the Iberian Mediterranean mountains in order to assess population trends and a hypothetical natural regeneration of the species.Area of study: Ayllón Mountain Range, Eastern end of Central Mountain Range, Spain.Material and methods: Afield survey was conducted on three yew groves, taking data of altitude, orientation, companion woody species, UTM coordinates, height, perimeter (at breast height, 120cm) and sex. Individuals were classified in four age groups, considering height and trunk perimeter: AgeGroup1, Seedling; AgeGroup2, Juvenile; AgeGroup3, Adult and AgeGroup4, Old. Finally Recruitment rate was calculated for each population.Main results: Surveyed yew populations include more than 1600 trees, showing elevated Recruitment rates, which indicates that there are more seedling and juvenile individuals (Group1 and Group2) than adult and old ones (Group3 and Group4).Research highlights: Surveyed yew populations show vigorous regeneration. These results lead us to reconsider the relictic character assigned to the species in the Iberian Mediterranean mountains.Key words: Ayllón; microclimatic; regeneration rate; relictic; survey.

Remise en production des bétulaies jaunes résineuses dégradées : étude du succès d'installation de la régénération

2007 ◽  
Vol 83 (5) ◽  
pp. 742-753 ◽  
Author(s):  
Pierre Gastaldello ◽  
Jean-Claude Ruel ◽  
Jean-Martin Lussier
Keyword(s):  
Natural Regeneration ◽  
Poor Quality ◽  
Betula Alleghaniensis ◽  
Light Conditions ◽  
Yellow Birch ◽  
Mixedwood Forests ◽  
The North ◽  
Open Canopy ◽  
Undisturbed Forest ◽  
Better Than

The abundance of poor quality stands in the North American hardwood and mixedwood forests poses important regeneration challenges. These stands have an open canopy with a well-developed shrub layer dominated by noncommercial species. The present study aims at testing the efficiency of a natural regeneration approach using a combination of brushing and spot scarification in the cleared strips. Four high-graded stands from the mixedwood zone in Quebec were selected and strips were cleared with a brush saw. Four microsite types created by the scarification were studied: 1-m and 2-m wide pockets, mounds and undisturbed forest floor. The amount of dispersed yellow birch seeds was adequate for two out of the three years of the study. Yellow birch establishment was in phase with seed years and was better on disturbed microsites. Best establishment was observed in seed spots and light conditions in these microsites after three years were better than on mounds or undisturbed ground. On the latter two, survival will likely be impaired by the poor light conditions. Seed spots remain receptive three years after scarification. Softwood regeneration was poor due to a lack of seed trees. The study has shown that seed tree abundance remains sufficient for natural regeneration even in these open stands. It also showed a very rapid regrowth of competing vegetation when root systems and seed banks were not removed by site preparation. Key words: yellow birch, Betula alleghaniensis, scarification, diameter-limit cutting, competition

scholarly journals Preliminary assessment of effect of disturbance on natural regeneration in gaps of different sizes

2020 ◽  
Vol 66 (No. 5) ◽  
pp. 185-196
Author(s):  
Maame Esi Hammond ◽  
Radek Pokorny
Keyword(s):  
Natural Regeneration ◽  
European Beech ◽  
Beech Forest ◽  
Gap Size ◽  
Light Conditions ◽  
Vegetation Zone ◽  
The Czech Republic ◽  
Growing Seasons ◽  
Direct Light ◽  
Before And After

The study focused on natural regeneration of European beech (Fagus sylvatica), Norway spruce (Picea abies) and European larch (Larix decidua) within very small and four times bigger size gaps following a disturbance at a mixed temperate forest in the Czech Republic. In spring 2013, experimental gap design starts, when 1 m2 circular sampling plots along transects were delineated within four selected naturally occurring canopy openings with size below 20 m2. In December 2013, these initial canopy openings were artificially enlarged by felling to 226 m2 for small and 904 m2 for big gaps. Regeneration was monitored in the next two consecutive growing seasons after disturbance. Light conditions were measured before and after disturbance. Results indicated that four times larger gaps increased twice levels of light conditions, and that diffuse light starts to equilibrate to direct light there. Large gaps were favouring larch regeneration. Beech regeneration was predominant, independently on gap size as the study area belongs naturally to Beech Forest Vegetation Zone, however, the decline of spruce regeneration was presumably linked to drought. Gap size explained variation of larch regeneration in gaps. Contrarily, gap size could not be associated with the prolific regeneration of beech and abysmal regeneration performances of spruce in gaps.

scholarly journals Which Selective Logging Intensity is Most Suitable for the Maintenance of Soil Properties and the Promotion of Natural Regeneration in Highly Continental Scots Pine Forests?–Results 19 Years after Harvest Operations in Mongolia

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 141 ◽  
Author(s):  
Gerelbaatar Sukhbaatar ◽  
Baatarbileg Nachin ◽  
Battulga Purevragchaa ◽  
Batsaikhan Ganbaatar ◽  
Khishigjargal Mookhor ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Total Nitrogen ◽  
Scots Pine ◽  
Natural Regeneration ◽  
Pine Forest ◽  
Selective Logging ◽  
Forest Steppe ◽  
Scots Pine Forest

Scots pine (Pinus sylvestris L.) forests are one of the main vegetation types in the Asian forest-steppe zone. However, over-harvesting currently threatens the natural regeneration and sustainability of these forests. In this study, we examine the long-term effects of different logging intensities on soil properties and natural regeneration in a natural Scots pine forest in the West Khentii Mountains (Mongolia), 19 years after selective logging. Our experimental design included five treatments: clear cut (CC), treatments with high (HI), medium (MI), low (LI) intensities, and a reference parcel with no logging impact at all (RE). We described and quantified the harvest events and applied ANOVA and LMM modeling to analyze and explain the long-term impacts of the logging intensities on soil properties and natural regeneration. We found that logging has a significant negative influence on the physical and chemical properties of the soil because it increases soil compaction and reduces soil nutrients. The most critical impacts of logging were on soil bulk density, total porosity, organic matter, and total nitrogen and phosphorus. The LMM modeling showed that organic matter (OgM), total nitrogen (TN), available K (AK) and pH values are especially impacted by logging. Our study revealed that the values for all of these variables show a linear decrease with increasing selective logging intensity and have a level of significance of p < 0.05. Another finding of this study is that selective logging with low and medium intensities can promote natural regeneration of Scots pine to numbers above those of the reference site (RE). High intensity logging and clear-cuts, however, limit the regeneration of Scots pine, reduce overall seedling numbers (p < 0.05), and create conditions that are suitable only for the regeneration of deciduous tree species. This underlines the risk of Scots pine forest degradation, either by replacement by broad-leaf trees or by conversion into non-forest ecosystems.

scholarly journals Natural regeneration of sessile oak under different light conditions

2011 ◽  
Vol 57 (No. 8) ◽  
pp. 359-368 ◽  
Author(s):  
I. Březina ◽  
L. Dobrovolný
Keyword(s):  
Light Intensity ◽  
Weed Control ◽  
Natural Regeneration ◽  
Small Area ◽  
Height Growth ◽  
Light Conditions ◽  
Site Factor ◽  
Sessile Oak ◽  
Regeneration Period ◽  
Positive Effect

Different variants of regeneration felling or different light conditions (total site factor 15&ndash;95%) and weed control were evaluated in relation to the 4-year development of individuals of regenerated sessile oak. The regeneration density is not dependent on light conditions. The highest mortality occurs on the open area of clear felling. For a certain time in youth, it is possible to consider oak as a shade-tolerating species. With the increasing light intensity the diameter and height growth of oak seedlings increases proportionally, being the highest at 100% light intensity. However, to support at least medium-fast growth, the species requires minimally 50% light intensity (smaller closed clear-felled areas). On the other hand, more extensive unprotected cleared areas appear to be quite unsuitable at the initial stages of regeneration. The positive effect of weed control on the success and growth of natural regeneration is questionable. We recommend developing the regenerated stand by means of a series of small-area (about &le; 0.3 ha) two-stage felling with a medium-long regeneration period (15&ndash;20 years). &nbsp;

scholarly journals ARAUSIS: Sistema de simulação para manejo sustentável de florestas de Araucária

FLORESTA ◽  
1999 ◽  
Vol 29 (12) ◽  
Author(s):  
CARLOS ROBERTO SANQUETTA
Keyword(s):  
Simulation Model ◽  
Natural Regeneration ◽  
Sustainable Management ◽  
Management Practices ◽  
Transition Probabilities ◽  
Selective Logging ◽  
Permanent Plots ◽  
Forest Fragments ◽  
Natural Forests ◽  
Separate Model

Este artigo apresenta um modelo de simulação para o manejo sustentável de Florestas Naturais de Araucária. Para validar o modelo foram utilizados dados advindos de três parcelas permanentes de um hectare, instaladas em 1995 e remedidas anualmente, situadas na Estação Experimental de São João do Triunfo, Centro-Sul do estado do Paraná. Informações sobre taxas de recrutamento, crescimento em diâmetro e mortalidade foram empregadas para o estudo, considerando a população de árvores com DAP acima de 10 cm. O modelo de simulação fundamentou-se na metodologia de matriz de transição, a qual considera um vetor de freqüências por classe de DAP inicial., probabilidade de transição de uma classe para outra e mortalidade para cada classe de diâmetro. Dez classes foram empregadas no estudo, considerando duas populações distintas: todas as espécies em conjunto (floresta) e a araucária em separado. Simulações feitas com o modelo para avaliar efeitos de práticas de manejo na floresta. Os resultados obtidos na simulação, apesar de preliminares, indicaram que as práticas de manejo permitidas pelos órgãos ambientais precisam ser revistas. Cortes seletivos de baixa magnitude em pequenos fragmentos florestais, como os que são geralmente praticados e permitidos por lei, não favorecem a regeneração natural do pinheiro, a principal espécie dentro da estrutura da floresta. O simulador ARAUSIS, imitando o que ocorre na natureza, indicou que é necessária a existência de perturbações mais severas e abertura de grandes clareiras na floresta para promover a regeneração natural do pinheiro. ARAUSIS: simulation system for sustainable management of araucaria forests Abstract This article presents a simulation model for the sustainable management of Araucaria Natural Forests. To validate the model, data coming from three permanent plots of one hectare each were used. The plots were established in 1995 in the Experimental Station at São João do Triunfo, Paraná State, and have been remeasured annually since then to provide figures on recruitment rates, tree diameter growth and mortality for individuals over 10 cm DBH. The simulation model was based on the transition matrix method, which considers a vector of initial frequencies by DBH class, transition probabilities of a class for other, and mortality, as well. Ten classes were used in this study, considering two different populations: all the species together (forest) and araucaria in separate. Model simulations were carried out to evaluate effects of logging practices in the forest. The results from simulations, despite of being preliminary ones, indicated that the management practices allowed by the environmental official institution in Paraná need to be reviewed. Selective logging of low magnitude in small forest fragments, as those that are generally practiced and allowed by the law, do not favor the natural regeneration of araucaria, the main species occurring in the forest. ARAUSIS simulator, imitating what happens in the reality, indicated that is necessary the existence of more severe disturbances and large openings in the forest to promote the natural regeneration of araucaria.

scholarly journals Effects of Gap Size and Cardinal Directions on Natural Regeneration, Growth Dynamics of Trees outside the Gaps and Soil Properties in European Beech Forests of Southern Italy

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1563
Author(s):  
Silvio Bagnato ◽  
Pasquale A. Marziliano ◽  
Maria Sidari ◽  
Carmelo Mallamaci ◽  
Federica Romeo ◽  
...  
Keyword(s):  
Soil Properties ◽  
Natural Regeneration ◽  
Growth Dynamics ◽  
European Beech ◽  
Tree Regeneration ◽  
Gap Size ◽  
Positive Effects ◽  
Beech Stand ◽  
Gap Opening ◽  
Cardinal Directions

The present study was focused on how cardinal directions inside gaps of different sizes (small, 200 m2; medium, 400 m2; and large, 600 m2) can affect soil characteristics and tree regeneration. Additionally, the effects of gap size on the growth dynamics of trees outside the gaps were evaluated. The study was carried out in a European beech stand located in Aspromonte National Park (Southern Apennines, Calabria, Italy). Microclimatic variables, physical, chemical, and biochemical soil properties, natural regeneration density, and growth trees outside the gaps density of natural regeneration were assessed. This study provided evidence for an important effect of cardinal points on micro-environmental parameter variability, nutrient cycle, physic-chemical soil properties, water availability, and biological processes such as trees growth and regeneration. The European beech natural regeneration was most abundant in the south part of the gaps. Thus, we can state that cardinal points affect the trees natural regeneration in a species-specific manner. The new microclimatic conditions due to the gap opening had positive effects on the tree growth located along the gap edge, especially in the trees sampled on the edges of the medium gaps. On the contrary, the trees located in the forest recorded a productivity coherent with the period prior the gap opening. In medium-sized gaps, the combination and interaction of microclimatic and soil parameters (humification and mineralization process and microbial activity) created the best conditions for beech natural regeneration and favored an increase in the productivity of the trees at the edge of the gaps.

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