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Growth and productivity modeling of seven Eucalyptus species in Souiniet's arboretum in the northwestern of Tunisia
2021
Mhamdi, Sameh | Elaieb, Mohamed Tahar | Souayah, Naoufel | Khouja, Mariem | Khouja, Mariem | Aloui, Ali | Candelier, Kévin
This study consists of the development of tree growth models to deduce stands productivity and determine the highest productive species in the conditions of the concerned plantation. Seven Eucalyptus, introduced in the arboretum of Souiniet (north-west of Tunisia, wet Mediterranean bioclimate) in a Cork Oak natural forest, were studied. Stem analysis and non-linear growth modeling regression equations were used to predict wood productivities. Gompertz and Chapman–Richards growth function appeared as being great numerical models to estimate the Eucalyptus tree diameter and height evolutions, respectively. Moreover, an adapted Chapman–Richards model allowed predicting the volume of trees in an efficient manner. The values of mean annual volume productivity of the Eucalyptus spp.studied, allow us to classify them in order of increasing annual productivity, as follows: E. sideroxylon, E. cinerea, E. maidenii, E. macrorhyncha, E. tereticornis, E. viminalis and E. bicostata. The first three Eucalyptus spp. appeared as the best-adapted and most suitable Eucalyptus trees for new plantations in this area. These species had the highest mean annual increments, ranged from 5 to 10 m3.ha−1.year−1 with 15 to 20 years of rotation. E. bicostata is the most promising, with annual average production exceeding 10 m3.ha−1.year−1 after 25 years, and reaching 20 m3.ha−1.year−1 at 40 years old. These modeling approaches provide additional knowledge on the productivity of the different Eucalyptus species, thus enabling forestry operators to simulate the development of forest stands in order to optimize timber production and harvesting.
Afficher plus [+] Moins [-]Effects of fire on forest communities and sclerophyllous scrubs in Central Chile as a basis for the formulation of restoration guidelines
2021
Castillo Soto, Miguel | Garfias Salinas, Roberto | Plaza Valencia, Álvaro
The effects of fire on forest and Mediterranean scrubs in four regions of Chile were studied. The main objective was to determine different levels of damage in watersheds with forest and native sclerophyllous scrubs belonging to the most valuable plant formations in Central Chile. The methodology consisted of the characterization of sampling areas that were qualitatively and quantitatively compared with the characterization of forests and shrublands without recent affectations of fires. Four regions of Chile were evaluated, where fires are concentrated in areas with sclerophyllous native vegetation. In each region, two sampling areas were selected to study the effects of fire. Three classifications were made based on structure, species composition, and response to fire. These were: deciduous scrub consisting of A. caven (tree), R. moschata (bush), and A. barbata (herbs); sclerophyllous evergreen scrub consisting of L. caustic-C. alba-and a mixed scrub of P. boldus (tree)-R. trinervia (scrub) and A. barbata. A dendrogram was produced on the relative abundances and the Bray & Curtis Similarity Index of the species. In addition, the results indicated an initial stage of damage to the soil structure, erosion processes, and water transport due to hydrophobicity at different levels of fire intensity, but recovery was observed a few weeks after the fire. Recovery was more apparent in the soil structure and cover of the scrub vegetation and later the tree species. These results provide useful background for the preparation of restoration, reforestation programs, and actions for the conservation of plant species vulnerable to the impact of wildfires. | "Fondo de Investigacion del Bosque Nativo" CONAF Project 008/2016 ANID-PFCHA/Doctorado Nacional 2020-21201582
Afficher plus [+] Moins [-]Proposals of rehabilitation and management actions for the protection of sclerophyllous forests affected by forest fires
2022
Castillo Soto, Miguel | Plaza Valencia, Álvaro
The damage and effects of fire on the native vegetation of Central Chile have been increasing in recent years due to drought conditions and the state of abandonment of the Mediterranean forests. The objective of this research was to study the damage and effects of fire in four regions of Central Chile, in order to establish adequate post-fire restoration proposals. The method consisted of the analysis of eight data sampling areas on native plant species affected by fire and sectors for statistical comparison (not burned). Consequently, it was possible to establish physical restoration measures and recovery proposals based on planting native species of the place affected by the fire. In conclusion, it can be indicated that Mediterranean landscapes need measures to accelerate the process of ecological restoration, due to the scarce recovery of vegetation due to the increase in the recurrence and intensity of forest fires. | Chilean Native Forest Research Fund | Versión publicada - versión final del editor
Afficher plus [+] Moins [-]Shifts That May Appear in Climate Classifications in Bursa Due to Global Climate Change
2024
Burak Arıcak | Uğur Cantürk | İsmail Koç | Ramazan Erdem | Hakan Şevik
Global climate change (GCC) is defined as a process that is considered the most crucial problem of the current century and will affect all living things and ecosystems in the world. In order to specify the potential impacts of this phenomenon, which does not seem possible to stop, it is necessary first to predict the change in climate types. Therefore, the current study aimed to define the shift of climate classifications (according to De Martonne, Erinç, and Emberger climate category) in 2040, 2060, 2080, and 2100 for Bursa, one of the largest cities in Türkiye, according to the SSPs 245 and SSPs585 scenarios, and compare it with its current situation. As a result, it was determined that the climate types in Bursa province would change significantly and primarily manifest as a shift into arid climate types. It is recommended to take precautions on a sectoral basis to avoid the devastating effects of GCC.
Afficher plus [+] Moins [-]Significance of Model Forest Stakeholders in the Management of Sustainable Forest Resources: The Case of Yalova Model Forest, Turkey
2024
Sultan Bekiroğlu | Mehmet Özdemir | Ercan Özyürek | Günay Çakır
Success of model forests, which are organized to support sustainable management of forests in collaboration with environmental, social, and economic forces on forest-based large territories, depends on the development of civil society index dimensions de"ned as “stakeholder participation,” “organizational structure,” “environment,” “values,” and “impact.” In this study, which was carried out within the scope of Yalova Model Forest, situation analysis strengths, weaknesses, opportunities, and threats analysis was used as a method. Literature and o'cial documents, expert opinions on “stakeholder engagement,” and data obtained through a 30-question survey were used as material. In this study, “historical development,” “legal regulations,” “activities” of Yalova Model Forest and weaknesses, strengths, opportunities, threats of civil society index and strategies pertaining to them were determined. Strengths, weaknesses, opportunities, and threats analysis was conducted by forming four separate focus groups for four dimensions of the Yalova Model Forest civil society index. According to the results of this study, the stakeholder participation dimension was concluded to be exceedingly inadequate. This is evidenced by advocate stakeholders’ insu'cient participation rates in activities, absence of adverse stakeholders in this reconciliation platform, and the fact that 99% of dormant–indi(erent stakeholders are unaware of this organization’s existence. Therefore, stakeholder participation dimension should be strengthened and the strategic plans that will be implemented should be prepared with the participation of stakeholders. Otherwise, Yalova Model Forest’s existence, as a civil society organization, will be jeopardized. However, active advocate stakeholders’ enthusiasm about resolving problems is reassuring for the future of Yalova Model Forest.
Afficher plus [+] Moins [-]Plant Diversity Affected by Litter and Soil Properties in Steppe-Forest Transition Zone
2024
Figen Çakır | Meriç Çakır
Especially steppe-forest ecotones, formed naturally or human-induced, are under threat due to overuse, inappropriate land use, and wrong interventions. These transition zones have long been a focus of interest for ecologists, and more research is needed, especially on the relationship between plant diversity and edaphic factors. The research area is located in the northern part of Çankırı province in Türkiye. The study used the line transect approach to evaluate the link between plant species diversity, litter, and soil parameters in the steppe-to-forest transition zone. The transects are about 12 kilometers long and create a line from the steppe to the forest. According to RDA findings, plant species diversity in the transition zone was significantly correlated with litter concentrations of Ca, K, P, and Mg. Plant biodiversity in the steppe zone correlated with soil Ca, CaCO3, Na, and pH levels. Our findings shed light on the relationship between plant diversity and edaphic (soil) properties in the steppe, forest, and transition zones. Elevated calcium levels in the steppe and transition zones indicate a higher appropriateness for calcicole plants (those that grow in calcium-rich habitats). This insight provides useful information for using native plant species in restoration and rehabilitation activities aimed at steppe and transition zone ecosystems.
Afficher plus [+] Moins [-]Climate Change and Anthropogenic Pressures on Forested Wetlands and Wetland Ecosystems in Cameroon: Sustainability and Policy Implications
2024
Nyong Princely Awazi | Amy Quandt | Titus Fondo Ambebe
Climate change is adversely impacting the agricultural sector through increasingly drier conditions, pushing farmers into wetlands. This has major implications on forested wetlands and wetland ecosystems. This study was carried out to assess how climate change is inducing the expansion of crop cultivation into forested wetlands and the implications on wetlands and wetland ecosystems in Cameroon. Findings revealed that the main extreme weather events driving the expansion of crop cultivation into forested wetlands are extreme sunshine, bush fires, scanty and erratic rainfall, prolong dry spells, high temperatures, and recurrent storms. Market garden crops and food/cash crops are the main types of crops cultivated by farmers in forested wetlands faced with weather extremes. Market garden crop cultivation increases the propensity of extension into forested wetlands compared to food/cash crops. Major implications of crop cultivation in forested wetlands are biodiversity loss, depletion of fresh water, and pollution. Favourable policies are needed to stem the tide of forested wetland degradation.
Afficher plus [+] Moins [-]Assessment of the Degradation of Teknaf Wildlife Sanctuary, Bangladesh: Use of Remote Sensing and Geographic Information System Techniques
2024
Md. Danesh Miah | Md. Akhter Hossain | Yaqub Ali
The Teknaf Wildlife Sanctuary (TWS), situated in the southeastern part of Bangladesh, is a crucial forest biodiversity hotspot in Bangladesh currently having tremendous pressure due to various socioeconomic factors. The key objective of the study is to find out the degradation of the forest cover by land use and land cover (LULC) classification of TWS from 1991 to 2021 using Google Earth Engine (GEE) application programming interface (API)-based supervised classification approaches. The study used satellite and key informant interviews (KIIs) data to detect the forest landscape’s degradation and find the potential solution to combat the degradation. It also used ArcGIS spatial analysis tools for LULC change detection and mapping. The investigation found that the dense forest vegetation in the TWS decreased by 1389 ha from 1991 (4665 ha) to 2021 (3277 ha), which is 12% of the study area. Similarly, the agricultural land, covering 3.34% of TWS, decreased by 388 ha from 1991 to 2021. The human settlement, light forests, and built-up areas showed an increase of 8% (930 ha), 6% (694 ha), and 1.3% (148 ha), respectively, in the last three decades. Although the increment of the built-up area is small, it poses severe threats to the biodiversity and flow of ecosystem services from TWS. The KIIs indicated that the Rohingya influx, overexploitation by high population density, lack of mass awareness, illegal felling, expansion of human settlements, and fuelwood supply to the brick fields, factories, government and non-government organization’s offices and warehouses are abiotic drivers of forest degradation. At the same time, cyclones, reduced rainfall, and increased temperature were the natural causes. The study suggested measures to combat the degradation of the forest landscape, enabling policymakers to plan measures to retard further degradation of the TWS and conserve the threatened and rare species for reinstalling the ecosystem services.
Afficher plus [+] Moins [-]Transformation of Jhum (Shifting Cultivation) to Forest Plantation: Effect on Soil Properties in the Hill Tracts of Bangladesh
2024
Al-Arafath Hossain Arman | Rabeya Khatun | Kazi Mohammad Masum
Natural and anthropogenic changes in the composition of tropical forests are expected to alter soil properties. Thus, an understanding of the effects on changes in crop/plant composition on soil properties is needed to choose better land-use options. So, the primary goal of this study was to examine the impacts of land-use change (from shifting cultivation to teak and rubber plantation) on some physico-chemical features (available P, K, N, pH, moisture content (MC), bulk density, organic matter (OM)) of soil. Soil physico-chemical properties were compared to a shifting cultivation land with a 14-yearold teak plantation and a 16-year-old rubber plantation that had previously been used for shifting cultivation. Results showed that soil properties change with the changes of crop/plant composition, such as phosphorus (P), K, and OM was significantly high in teak and rubber plantation than the shifting cultivation area both in surface (0–10 cm) and sub-surface (10–20 cm) soil layers. Teak (3.5689 mg/kg) and rubber (3.5478 mg/kg) plantations exhibited significantly higher mean P content (p < .01) compared to shifting cultivation (3.4678 mg/kg). Shifting cultivation had the maximum K levels (0.2233 meq/100 g), while teak (0.2833 meq/100 g) and rubber (0.2733 meq/100 g) plantations showed significantly higher values (p < .05). Moisture content was 1.13% higher in teak and 1.2% higher in rubber plantations than in shifting cultivation. Furthermore, OM content was significantly higher in teak and rubber plantations (5.2744%, 5.2567%) compared to shifting cultivation (4.5067%). On the other hand, total nitrogen (N) and pH levels showed no significant difference among the landuse types. Finally, the study showed that conversion to teak and rubber plantation could lead to positive change in the soil properties. Hence it suggested that this can be undertaken/chosen as a better land cover option for shifting cultivated land in Chittagong Hill Tracts (CHTs) from soil conservation point of view.
Afficher plus [+] Moins [-]Evaluation of the Efficiency of WARSEM Model and the Effect of Fill Slope Information on Changing the Model Results
2024
Alireza Ghomi Motazeh | Ramin Naghdi | Edris Taghvaye Salimi | Abdullah Emin Akay
As far as numerous researchers are concerned, the main source of sediment in forests is roads and their related elements. Due to the importance of this issue, research has been conducted extensively in this regard. Therefore, the main purpose of this research was to evaluate the efficiency of the WARSEM model in the study area. To achieve this goal, in addition to determining the appropriate correction factor to calibrate the model, evaluating the effect of fill slope factors on the accuracy of the results of WARSEM model in the study area was desirable as well. The study area was a part of the Hyrcanian forests in the Northwest Iran. After recording fixed information along the road, fieldwork was done for a whole year because it was decided to utilize natural rainfall showers in the study process. The field observations indicated that the amount of sediment in the study area was high; nevertheless, the WARSEM has about a 19% overestimate in the study area. Thus, the calibration index for the study area was supposed to be 0.81, based on bringing the R2, NS, and RMSE closer to acceptable values. Also, the results showed that the amount of fill slope sediment does not cause a significant change in the overall results. Therefore, the opinion of the model designers is also valid in the study area. Moreover, the results indicated that road gradient and delivery factor are more effective than other factors in changing the result of the model.
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