scholarly journals Comparison of Natural Regeneration in Natural Grassland and Pine Plantations across an Elevational Gradient in the Páramo Ecosystem of Southern Ecuador

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 745 ◽  
Author(s):  
Dahik ◽  
Marín ◽  
Arias ◽  
Crespo ◽  
Weber ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Plant Cover ◽  
Basal Area ◽  
Woody Species ◽  
Elevational Gradient ◽  
Pine Plantations ◽  
Shade Tolerant Species ◽  
Elevational Range ◽  
Pinus Spp ◽  
Natural Grassland

During the 1980s, reforestation programs using exotic species (Pinus spp.) were established in the páramo ecosystem of Ecuador. The aims of this study were: (1) to compare the natural regeneration between pine plantations (Pi) and natural grassland (NG) across an elevational gradient and (2) to identify the attributes of Pi and soil properties that were influencing herbaceous and woody plant composition and their plant cover. In total, six independent Pinus patula (Schltdl. & Cham. plantations (two per each elevation) were selected and distributed in an elevational range (3200–3400, 3400–3600, 3600–3800 m a.s.l.). Adjacent to Pi, plots in NG were established for recording natural regeneration. Both, namely the attributes and the soil samples, were measured in Pi. The results showed that natural regeneration differs significantly between both types of vegetation. As expected, NG holds more plant diversity than Pi; the elevational range showed a clear tendency that there was more herbaceous richness when elevation range increases, while the opposite was found for woody species. Moreover, attributes of Pi influenced herbaceous and woody vegetation, when saturated hydraulic conductivity (Ksat) in the soil, basal area (BA) and canopy density (CD) increased, herbaceous species richness and its cover decreseased; and when Ksat and the acidity in the soil increased, woody plants richness and its cover decreased. The plantations have facilitated the establishment of shade tolerant species. More studies are needed to evaluate if removal with adequate management of pine plantations can improve the restoration and conservation of the native vegetation of the páramo ecosystem.

scholarly journals Impacts of pine plantations on carbon stocks of páramo sites in southern Ecuador

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Carlos Quiroz Dahik ◽  
Patricio Crespo ◽  
Bernd Stimm ◽  
Reinhard Mosandl ◽  
Jorge Cueva ◽  
...  
Keyword(s):  
Land Use ◽  
Elevational Gradient ◽  
Carbon Stocks ◽  
Pine Plantations ◽  
Site Quality ◽  
Accurate Estimation ◽  
Carbon Pools ◽  
Limiting Factor ◽  
The Impact ◽  
Natural Grassland

Abstract Background Since the 1990’s, afforestation programs in the páramo have been implemented to offset carbon emissions through carbon sequestration, mainly using pine plantations. However, several studies have indicated that after the establishment of pine plantations in grasslands, there is an alteration of carbon pools including a decrease of the soil organic carbon (SOC) pool. The aim of this study is to investigate the impact of the establishment of pine plantations on the carbon stocks in different altitudes of the páramo ecosystem of South Ecuador. Results At seven locations within an elevational gradient from 2780 to 3760 m a.s.l., we measured and compared carbon stocks of three types of land use: natural grassland, grazed páramo, and Pinus patula Schlltdl. & Cham. plantation sites. For a more accurate estimation of pine tree carbon, we developed our own allometric equations. There were significant (p < 0.05) differences between the amounts of carbon stored in the carbon pools aboveground and belowground for the three types of land use. In most of the locations, pine plantations revealed the highest amounts of aboveground and belowground carbon (55.4 and 6.9 tC/ha) followed by natural grassland (23.1 and 2.7 tC/ha) and grazed páramo sites (9.1 and 1.5 tC/ha). Concerning the SOC pools, most of the locations revealed significant lower values of plantations’ SOC in comparison to natural grassland and grazed páramo sites. Higher elevation was associated with lower amounts of pines’ biomass. Conclusions Even though plantations store high amounts of carbon, natural páramo grassland can also store substantial amounts above and belowground, without negatively affecting the soils and putting other páramo ecosystem services at risk. Consequently, plans for afforestation in the páramo should be assessed case by case, considering not only the limiting factor of elevation, but also the site quality especially affected by the type of previous land use.

scholarly journals Forest regeneration and seed rain in the conversion of a stand of Pinus sp. into native forest

Biotemas ◽  
2021 ◽  
Vol 34 (2) ◽  
pp. 1-18
Author(s):  
Geraldo Ceni Coelho ◽  
Rachel Palhares Alcantara ◽  
Maurício Zinn Klemann ◽  
Leandro Klemann
Keyword(s):  
Forest Restoration ◽  
Sustainable Use ◽  
Basal Area ◽  
Woody Species ◽  
Seed Rain ◽  
Native Forest ◽  
Management Plans ◽  
Spontaneous Regeneration ◽  
One Year ◽  
Pinus Spp

In Southern Brazil, the National Forests (NF) are protected areas of sustainable use; however, most of them present a significant cover with old plantations of Pinus spp. established to foster commercial forestry. Nowadays, the NF management plans propose the conversion of Pinus stands into native forests. Pinus spp. are worrisome invasive plants whose spontaneous recruitment is a challenge to forest restoration. This paper aims to analyze seed rain and woody community composition in a stand where Pinus trees were eliminated to drive spontaneous regeneration (REG) in an NF in the Southern Atlantic Forest. The seed rain was measured in the restoring area and inside an adjacent Pinus stand (PIN). The tree community structure was analyzed comparatively in REG, PIN, and in a Native Araucaria Forest (NAT). One year after Pinus cutting, the seed rain of woody species was 1,802 and 1,502 seeds m-2.year-1 in REG and PIN, respectively. REG’s seed rain had higher diversity than PIN and absence of Pinus seeds. REG and NAT presented higher diversity of tree species than PIN, although REG had the lowest basal area and tree density. Nevertheless, 188 Pinus seedlings.ha-1 were observed in REG, which indicates that complementary restoration actions are needed.

scholarly journals Evaluating Regeneration in Heterobasidion Root Disease Infested Stands in the Lake States

2019 ◽  
Vol 66 (2) ◽  
pp. 141-144
Author(s):  
Michael C Demchik ◽  
Monique L Sakalidis ◽  
Michael Hillstrom ◽  
Kyoko Scanlon ◽  
Trevor A Adams ◽  
...  
Keyword(s):  
Invasive Species ◽  
Tree Species ◽  
Natural Regeneration ◽  
Basal Area ◽  
Root Disease ◽  
Red Pine ◽  
Pine Plantations ◽  
Lake States ◽  
Overstory Trees

Abstract Heterobasidion root disease (HRD) infection is becoming increasingly common in red pine plantations of the Lake States. Although stump treatment can reduce rates of overland transmission, infested stands continue to experience expansion of mortality pockets. Natural regeneration into HRD mortality pockets can assist with revegetation. The objective of this study was to determine what tree species naturally regenerate in red pine plantations impacted by HRD in Wisconsin and Michigan. We visited 49 pockets (in 31 stands) in Wisconsin and Michigan that had existing confirmed HRD infections during the fall of 2017. We surveyed the regeneration in the pocket and measured the species and basal area of overstory trees 10 m from the expanding edge of the pocket. Overall, pockets were regenerating with desirable species, some of which are susceptible to HRD. Additionally, woody invasive species were present in 39 percent of the pockets. We expect these pockets to generally fill with desirable species of regeneration, although long-term successful regeneration by susceptible species such as pines may be limited.

scholarly journals Woody Species Composition, Vegetation Structure, and Regeneration Status of Majang Forest Biosphere Reserves in Southwestern Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Semegnew Tadese ◽  
Teshome Soromessa ◽  
Tesefaye Bekele ◽  
Getaneh Gebeyehu
Keyword(s):  
Plant Species ◽  
Vegetation Structure ◽  
Natural Regeneration ◽  
Woody Plant ◽  
Basal Area ◽  
Woody Species ◽  
Site Factors ◽  
Biosphere Reserves ◽  
Regeneration Status ◽  
Study Sites

The aim of this study was to analyse the species composition, structures, and regeneration of woody plant species and the impacts of site factors on the natural regeneration of tree species in four study sites of MFBR. The vegetation data were collected systematically in 140 plots with the size of 400 m2 for trees; 25 m2 for seedlings, saplings, shrubs, and lianas; and 1 m2 for herbs. Individual tree and shrub DBH ≥ 5 cm were measured and counted. The diameter at breast height (DBH), frequency, basal area, importance value index (IVI), and density were used for vegetation structure description and regeneration. A total of 158 plant species belonging to 115 genera, 56 families, and 80 species (51%) trees, 26 (16%) shrubs, 19 (12%) herbs, and 33 (21%) lianas were identified and recorded. The most dominant families were Euphorbiaceae, Rubiaceae, and Moraceae, each represented by 13 species (7.4%), 12 species (6.8%), and 10 species (5.7%), respectively. The tree densities varied from 1232 to 1478 stem ha−1, sapling density 176.8 to 708.7 stem ha−1, and seedling density 534.7 to 1657.5 stem ha−1, with an average basal area of 63.6 m2 in the study sites. Dracaena afromontana was the most frequent woody species in the MFBR occurring in 90% followed by Celtis zenkeri (65%) and Pouteria altissima (62.5%). The regeneration status of all the woody plant species was categorised as “not regenerate” (9.6%), “poor” (30.7%), “fair” (59.5%), and “good” (10.8%) in all sites. The correlation result between natural regeneration and site factors revealed both positive and negative relationships. However, the main threat to the biosphere reserve is illegal logging for different purposes. Therefore, awareness creation on sustainable forest management, utilisation, conservation of priority species, and livelihood diversification to the local community and encouraging community and private woodlot plantation in the transitional zone of biosphere reserves are recommended.

scholarly journals The composition and diversity of natural regeneration of tree species in gaps under different intensities of forest disturbance

2021 ◽  
Author(s):  
Maame Esi Hammond ◽  
Radek Pokorný ◽  
Daniel Okae-Anti ◽  
Augustine Gyedu ◽  
Irene Otwuwa Obeng
Keyword(s):  
Tree Species ◽  
Natural Regeneration ◽  
Forest Disturbance ◽  
Forest Site ◽  
Gap Formation ◽  
Tree Species Composition ◽  
Forest Sites ◽  
Significant Difference ◽  
Shade Tolerant Species ◽  
Disturbed Forest

AbstractThe positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration < 350 cm height were gathered. The results show that the intensity of disturbance was disproportional to gap size. Species diversity differed significantly between undisturbed and disturbed sites and, also between intermittently disturbed and disturbed sites for Simpson’s (1-D), Equitability (J), and Berger–Parker (B–P) indices. However, there was no significant difference among forest sites for Shannon diversity (H) and Margalef richness (MI) indices. Tree species composition on the sites differed. Regeneration density on the disturbed site was significantly higher than on the two other sites. Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers. Pioneer species giving way to shade tolerant species is a natural process, thus make them worst variant in gap regeneration.

scholarly journals Big trees drive forest structure patterns across a lowland Amazon regrowth gradient

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tassiana Maylla Fontoura Caron ◽  
Victor Juan Ulises Rodriguez Chuma ◽  
Alexander Arévalo Sandi ◽  
Darren Norris
Keyword(s):  
Forest Structure ◽  
Natural Regeneration ◽  
Basal Area ◽  
Significant Decline ◽  
Forest Regrowth ◽  
Large Trees ◽  
Amazonian Forests ◽  
Mammal Diversity ◽  
Structure Patterns ◽  
Plot Type

AbstractDegraded Amazonian forests can take decades to recover and the ecological results of natural regeneration are still uncertain. Here we use field data collected across 15 lowland Amazon smallholder properties to examine the relationships between forest structure, mammal diversity, regrowth type, regrowth age, topography and hydrology. Forest structure was quantified together with mammal diversity in 30 paired regrowth-control plots. Forest regrowth stage was classified into three groups: late second-regrowth, early second-regrowth and abandoned pasture. Basal area in regrowth plots remained less than half that recorded in control plots even after 20–25 years. Although basal area did increase in sequence from pasture, early to late-regrowth plots, there was a significant decline in basal area of late-regrowth control plots associated with a decline in the proportion of large trees. Variation in different forest structure responses was explained by contrasting variables, with the proportion of small trees (DBH < 20 cm) most strongly explained by topography (altitude and slope) whereas the proportion of large trees (DBH > 60 cm) was explained by plot type (control vs. regrowth) and regrowth class. These findings support calls for increased efforts to actively conserve large trees to avoid retrogressive succession around edges of degraded Amazon forests.

Modelling the susceptibility of pine stands to bark stripping by Chacma baboons (Papio ursinus) in the Mpumalanga Province of South Africa

2017 ◽  
Vol 44 (4) ◽  
pp. 298 ◽  
Author(s):  
Ilaria Germishuizen ◽  
Kabir Peerbhay ◽  
Riyad Ismail
Keyword(s):  
South Africa ◽  
Random Forests ◽  
Risk Evaluation ◽  
Site Index ◽  
Pine Plantations ◽  
Bark Stripping ◽  
Papio Ursinus ◽  
Mpumalanga Province ◽  
Chacma Baboons ◽  
Pinus Spp

Context Commercial pine (Pinus spp.) plantations in southern Africa have been subjected to bark stripping by Chacma baboons (Papio ursinus) for many decades, resulting in severe financial losses to producers. The drivers of this behaviour are not fully understood and have been partially attributed to resource distribution and availability. Aims The study sought to develop a spatially explicit ecological-risk model for bark stripping by baboons to understand the environmental factors associated with the presence of damage in the pine plantations of the Mpumalanga province of South Africa. Methods The model was developed in Random Forests, a machine learning algorithm. Baboon damage information was collected through systematic surveys of forest plantations conducted annually. Environmental predictors included aspects of climate, topography and compartment-specific attributes. The model was applied to the pine plantations of the study area for risk evaluation. Key results The Random Forests classifier was successful in predicting damage occurrence (F1 score=0.84, area under curve (AUC)=0.96). Variable predictors that contributed most to the model classification accuracy were related to pine-stand characteristics, with the age of trees being the most important predictor, followed by species, site index and altitude. Variables pertaining to the environment surrounding a pine stand did not contribute substantially to the model performance. Key conclusions (1) The study suggests that bark stripping is influenced by compartment attributes; (2) predicted risk of bark stripping is higher in stands above the age of 5 years planted on high-productivity forestry sites, where site index (SI) is above 25; (3) presence of damage is not related to the proximity to natural areas; (4) further studies are required to investigate ecological and behavioural patterns associated with bark stripping. Implications The model provides a tool for understanding the potential extent of the risk of bark stripping by baboons within this region and it can be applied to other forestry areas in South Africa for risk evaluation. It contributes towards the assessment of natural hazards potentially affecting pine plantations and supports the development of risk-management strategies by forest managers. The model highlights opportunities for cultural interventions that may be tested for damage control.

Insect Herbivory on the Plant Rhinanthus minor over its Elevational Range in the Canadian Rockies

2018 ◽  
Author(s):  
Lindsey Falk
Keyword(s):  
Insect Herbivory ◽  
Elevational Gradient ◽  
Scientific Models ◽  
Biotic Factors ◽  
Plant Interactions ◽  
Plant Populations ◽  
Species Ranges ◽  
Pesticide Treatment ◽  
Rhinanthus Minor ◽  
Elevational Range

All species of plants and animals occur over a finite area of the Earth’s surface. This is referred to as the species range, and many species ranges have shifted or are predicted to shift with climate change. Scientific models have predicted how these shifts are expected to change and what proportion of the implicated species will go extinct in the process. Most models assume that climatic variables such as temperature and rainfall are solely responsible for these range shifts. However, we know that the success of a species is strongly influenced by both their positive and negative interactions with other species, such as competition, mutualism, predation and herbivory. But how these biotic factors affect species ranges is poorly understood. I am using a field experiment on a species in its native habitat to better understand these interactions.  My study took place in the Canadian Rocky Mountains on populations of the plant Yellow Rattle (Rhinanthus minor). I studied two transects, each with plant populations at low, mid and high elevations. Insect herbivory on plant populations was observed, as well as manipulated, via a pesticide treatment to reduce insect herbivory, and a clipping treatment to simulate natural insect herbivory. Understanding herbivory and herbivore-plant interactions over an elevational gradient may help give us a clearer idea of the complex relationship between the climatic and biotic factors that affect plant species ranges.

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.

Woody plant restoration and natural regeneration in wet meadow at Coomonderry Swamp on the south coast of New South Wales

2000 ◽  
Vol 51 (1) ◽  
pp. 81 ◽  
Author(s):  
N. H. de Jong
Keyword(s):  
Natural Regeneration ◽  
New South ◽  
Woody Species ◽  
Cost Effective ◽  
Wet Meadow ◽  
Casuarina Glauca ◽  
South Wales ◽  
Plant Restoration ◽  
Inhibited Acid ◽  
Sulfate Soils

This study investigated planting techniques and natural regeneration of indigenous woody species within degraded wet meadow wetland at Coomonderry Swamp. Planting tubestock directly into existing vegetation was practical and cost-effective. Clearing of plots allowed infiltration of weeds, early growth of tubestock was inhibited, acid sulfate soils were exposed, and open inundated plots were choked by algae. After four years, Melaleuca ericifolia and Melaleuca linariifolia showed good survivorship at upper and lower elevations. Eucalyptus robusta and Casuarina glauca were more successful at upper elevations, and Leptospermum juniperinum did not succeed at either elevation. These results corresponded to patterns of regeneration and to distributions within undisturbed stands. Despite the evidence of natural regeneration, direct seeding was not successful at the experimental site. Given that poor dispersal was indicated at Coomonderry Swamp, it is unlikely that isolated wetlands in the region could rely solely on seed dispersal for woody revegetation. Even where regeneration can occur naturally, some planting or culling might be required if the desired outcome is a species mix comparable to that observed on undisturbed margins.

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