Search Results (65)

Deforestation and land-use changes lead to significant soil degradation and erosion, particularly in Amazonian ecosystems, due to the region’s climate and geology. This study characterizes soil quality using physical, chemical, and biological parameters across different land uses. It uses a soil quality index (SQI) based on a minimum data set (MDS), from 19 evaluated parameters. The land uses evaluated were cacao monoculture (CMC), agroforestry systems associated with fruit and timber species (FAFS and TAFS, respectively), and a secondary forest. The SQI was composed of six variables, bulk density (BD), soil organic matter (SOM), urease activity (UR), pH, dehydrogenase activity (DH), and leaf litter, which are considered relevant indicators that allow for an adequate evaluation of soil quality. According to the SQI assessment, FAFS has a moderate-quality rating (0.40), followed by secondary forest (0.35), TAFS (0.33), and CMC (0.30), the last three categorized as low-quality. The methods used are replicable and efficient for evaluating changes in soil properties based on different land uses and management systems in landscapes similar to those of the Ecuadorian Amazon. Also worth mentioning is the potential of agroforestry as a sustainable land-use strategy that can enhance above- and below-ground biodiversity and nutrient cycling. Therefore, implementing agroforestry practices can contribute to long-term soil conservation and the resilience of tropical ecosystems. Full article

Masting, or the synchronous and intermittent production of seeds, can have profound consequences for Tropical Montane Cloud Forest (TMCF) tree populations and the trophic webs that depend on their mass flowering and seeds. Over the past 80 years, the importance of Fagus mexicana Martínez (Mexican beech) masting has become apparent in terms of conservation and management, promoting regeneration, and conserving endangered tree species, as well as the conscientious development of edible beechnuts as a non-timber forest product. The establishment of the relict-endemic Mexican beech is unknown, and several microenvironmental factors could influence natural regeneration. Thus, this study was conducted in two well-preserved Mexican beech forests to assess the influence of light incidence and soil moisture on the natural germination and seedling establishment of beeches. During two masting years (2017 and 2024), we assessed in situ beechnut germination and establishment. We tested the effect of the microenvironment of the oldest beeches on beechnut germination and seedling establishment. Our study highlights the complexity of the microenvironment of old beeches influencing the early stages of establishment and provides insights into possible conservation actions aimed at mitigating the impact of environmental change and humans. Full article

Bamboo forest ecosystems are an important component of the Earth’s terrestrial ecosystems and play an important role in addressing the global timber crisis as well as climate change. Bamboo is a typical shallow-rooted, fast-growing clonal plant species whose developed rhizome system and high canopy closure play an important role in soil and water conservation. The function of soil and water conservation services of bamboo forests can intuitively reflect the regional regulation of precipitation, the redistribution function of precipitation, and the function of soil fixation, which is one of the crucial ecological service functions in regional ecosystems. Bamboo forests are divided into monopodial bamboo forests, sympodial bamboo forests, and mixed bamboo forests, which are mainly distributed in tropical and subtropical mountainous areas. The region’s variable climate, abundant precipitation, and high potential risk of soil erosion, in conjunction with the frequent operation of bamboo forests and frequent occurrence of extreme weather events, have the potential to adversely affect the ecosystem function of bamboo forests. Presently, bamboo forests are primarily managed through the cultivation of bamboo, with the objective of enhancing productivity. Extensive research has been conducted on the long-term maintenance of bamboo forest productivity. However, there is a paucity of research on the mechanisms of management measures for ecosystem stability and the development of adaptive management technology systems suitable for soil and water conservation, carbon sequestration and sink enhancement, and biodiversity conservation. This paper is predicated on the biological characteristics of bamboo and, thus, aims to compile the extant research progress on the following subjects: the role of rainfall redistribution in bamboo forest canopies, the role of deadfall interception, and the mechanism of soil fixation mechanics of the root system. It also synthesizes the current status of research on the impact of traditional management measures on the soil and water conservation function of bamboo forests. Finally, it discusses the problems of current research and the direction of future development. Full article

The tropical tree species Symplocos cochinchinensis plays a crucial role in ecological restoration and serves as a resource for traditional medicine, dyeing, and timber production. Assessing its distribution patterns and adaptive responses to global climate change is essential for maintaining ecosystems and developing conservation strategies. This study elucidates the spatial distribution patterns and projects potential geographic shifts of the widely distributed tropical species S. cochinchinensis under climate change scenarios. A compilation of data from global and local herbaria and databases yielded 5050 occurrence records, covering the majority of its native range in the tropics and subtropics. We modeled the species’ potential habitats using the maximum entropy (MaxEnt) principle for current, 2050, and 2070 climate scenarios under high-emission SSP585. Our analysis reveals that sampling bias substantially influences the observed distribution patterns of S. cochinchinensis. Predictions indicate a decrease in barely suitable habitats and an increase in areas deemed highly suitable, suggesting climate change stress and an ecological niche shift towards areas with favorable microclimates with “Precipitation of Wettest Month” (Bio 13) and “Mean Temperature of Wettest Quarter” (Bio 8). Our findings reveal S. cochinchinensis’s adaptive resilience, offering valuable insights for developing strategies and conservation management in Southeast Asia, as well as a reference for the response of other common tropical species to climate change. Full article

Human-caused habitat conversion, degradation, and climate change threaten global biodiversity, particularly in tropical forests where vascular epiphytes—non-parasitic plants growing on other plants—may be especially vulnerable. Epiphytes play vital ecological roles, in nutrient cycling and by providing habitat, but are disproportionately affected by land-use changes due to their reliance on host trees and specific microclimatic conditions. While tree species in secondary forests recover relatively quickly, epiphyte recolonization is slower, especially in humid montane regions, where species richness may decline by up to 96% compared to primary or old-growth forests. A review of nearly 300 pertinent studies has revealed a geographic bias toward the Neotropics, with limited research from tropical Asia, Africa, and temperate regions. The studies can be grouped into four main areas: 1. trade, use and conservation, 2. ecological effects of climate and land-use change, 3. diversity in human-modified habitats, and 4. responses to disturbance. In agricultural and timber plantations, particularly those using exotic species like pine and eucalyptus, epiphyte diversity is significantly reduced. In contrast, most native tree species and shade-grown agroforestry systems support higher species richness. Traditional polycultures with dense canopy cover maintain up to 88% of epiphyte diversity, while intensive management practices, such as epiphyte removal in coffee and cacao plantations, cause substantial biodiversity losses. Conservation strategies should prioritize preserving old-growth forests, maintaining forest fragments, and minimizing intensive land management. Active restoration, including the translocation of fallen epiphytes and planting vegetation nuclei, is more effective than passive approaches. Future research should include long-term monitoring to understand epiphyte dynamics and assess the broader impacts of epiphyte loss on biodiversity and ecosystem functioning. Full article

The effect of timber cutting and related management on species composition and diversity in tropical forests has been reported in earlier studies, but the potentially different effects on understory and canopy tree species remains unclear. Our study aim was to assess the variation in species composition and diversity of understory and canopy species along a timber removal (“logging”) gradient. We assessed the species composition, alpha and beta diversity, and compared species composition of canopy trees in plots with different management histories in Budongo. Our findings revealed logging contributed 18.1% to the beta diversity of species composition as measured by distance-based redundancy analysis (dbRDA) and species composition decreased with logging intensity (R² = −0.415). Unlogged forest had higher species diversity for both understory and canopy tree species compared with logged forests. Species composition of logged/unlogged forests were significantly different from those of the forest succession types. Our study adds new information on the effect of logging on the species composition of understory and canopy trees in lowland tropical forests. We found logged forests do not recover species composition within seven decades, diversity within, and what previously distinct successional types were, have become, and remain, mixed in nature. Full article

Ensuring the sustainability of forests is among the priority measures to be taken against the decline in biodiversity, which is among the world’s increasingly common concerns. This study investigated whether sustainable forest management processes are considering wildlife conservation objectives. Ten forest management processes were categorized and then analyzed for whether wildlife conservation is adequately considered. The wildlife data were grouped into four categories, with the most common being the protection of biodiversity and wildlife trade. The satisfaction level obtained according to the scoring method used was determined as the criterion of success in wildlife conservation. According to the scoring method applied, the overall success was found to be 50%. It was determined that a standard should be developed regarding the economic value of wildlife fauna and flora species and that this issue should be included in sustainable forest management strategies. Only 20 of 116 total sustainable forest management criteria considered wildlife. The African Timber Organization process, which has the most member countries, was identified as the process with the lowest number of wildlife criteria, at 2%, while the International Tropical Timber Organization process was found to have the most wildlife protection criteria at 20%. The conservation success rates for the two processes of which Türkiye is a member were also found to be quite low. It is concluded that there is a need to strengthen the place of wildlife, one of the most important living components for forests, in SFM processes both for Türkiye and internationally. The results obtained were evaluated both in terms of international criteria and practices in Türkiye. It is also recommended that future international meetings include wildlife health and diversity as a separate criterion when determining sustainable methods. Full article

The scarcity of hardwoods from tropical forests makes the search for alternative species necessary for commercialization. This study aimed to establish groups of timber species from the Amazon Forest with potential for logging purposes through the assessment of their physical-mechanical properties, aiming to identify alternative species that can meet the market demands. We utilized data from the Forest Products Laboratory (LPF) (containing information on basic density and other wood mechanical properties) and the Timberflow platform, as well. We applied a multivariate cluster analysis technique with the aim of grouping species based on the technological characteristics of their wood and evaluating similarity among them to obtain homogeneous groups in terms of economic potential and utilization. The results indicated four homogeneous groups: Cluster 1 (40.72% of species, basic density-db: 690 kg m⁻³), Cluster 2 (13.92%, db: 260 and 520 kg m⁻³), Cluster 3 (27.32%, db: 550 and 830 kg m⁻³), and Cluster 4 (18.04%, db: 830 kg m⁻³). Most of the 20 listed species are classified as more commercially viable (70%), with high wood density. Species identified as alternatives include Dialium guianense and Zollernia paraensis for Dipteryx odorata, Terminalia argentea for Dinizia excelsa, Terminalia amazonia and Buchenavia grandis for Goupia glabra, and Protium altissimum and Maclura tinctoria for Hymenaea courbaril. The analysis highlighted the overexploitation of a restricted group of species and the need to find alternatives to ensure the sustainability of forest management. This study contributed to identifying species that can serve as alternatives to commercial ones, promoting a more balanced and sustainable forest management. Full article

Seedling growth is one of the most important stages for the establishment of natural and artificial regeneration. For the first time, the initial growth and biomass allocation of seedlings germinated from cryostored seeds of Parkia nitida were analyzed. P. nitida is an economically and ecologically important timber tree species distributed in Central and South America. Cryostored seeds germinated quickly after priming by scarifying a part of the seedcoat with emery paper, reaching a germination percentage of 94%. Thirteen weeks after germination, the seedlings grew to a height of 16.5 to 60.0 cm. The results of our study, under different day/night alternating culture temperatures, showed that culture temperature had a direct correlation with seedling growth, total biomass allocation, and biomass partitioning. The greatest growth (height, diameter, and number of node sections) and greatest biomass allocation (leaf, stem, and root weight) were recorded under alternating temperatures of 30/25 °C, and these decreased with decreasing culture temperatures to 25/20 °C and 20/15 °C. Shoot:Root (S:R) ratios also decreased with decreasing culture temperatures, but a statistically significant difference (p < 0.05) was only observed between 20/15 °C and 30/25 °C. However, significant differences were not observed in Photosynthetic:Non-photosynthetic organ ratios among the different alternating culture temperatures. This study provides fundamental information for the production of good-quality seedlings of the fast-growing tropical trees of the legume family. Full article

Leucaena is a versatile legume shrub/tree used as tropical livestock forage and in timber industries, but it is considered a high environmental weed risk due to its prolific seed production and broad environmental adaptation. Interspecific crossings between Leucaena species have been used to create non-flowering or sterile triploids that can display reduced weediness and other desirable traits for broad use in forest and agricultural settings. However, assessing the success of the hybridisation process before evaluating the sterility of putative hybrids in the target environment is advisable. Here, RNA sequencing was used to develop breeding markers for hybrid parental identification in Leucaena. RNA-seq was carried out on 20 diploid and one tetraploid Leucaena taxa, and transcriptome-wide unique genetic variants were identified relative to a L. trichandra draft genome. Over 16 million single-nucleotide polymorphisms (SNPs) and 0.8 million insertions and deletions (indels) were mapped. These sequence variations can differentiate all species of Leucaena from one another, and a core set of about 75,000 variants can be genetically mapped and transformed into genotyping arrays/chips for the conduction of population genetics, diversity assessment, and genome-wide association studies in Leucaena. For genetic fingerprinting, more than 1500 variants with even allele frequencies (0.4–0.6) among all species were filtered out for marker development and testing in planta. Notably, SNPs were preferable for future testing as they were more accurate and displayed higher transferability within the genus than indels. Hybridity testing of ca. 3300 putative progenies using SNP markers was also more reliable and highly consistent with the field observations. The developed markers pave the way for rapid, accurate, and cost-effective diversity assessments, variety identification and breeding selection in Leucaena. Full article

Tropical forest management has a potential role in forest conservation if it is sustainable. This study of a forest under management in Bolivian Amazonia strongly suggests that the management project is not sustainable and that no potential changes in management would be likely to make it so. In a 216.41 ha harvested area, 278 commercial trees from 10 families, 15 genera, and 15 species were measured. The density of commercial species with diameter at breast height (DBH) ≥ 50 cm was 1.28 trees ha⁻¹, and the harvestable commercial volume was 12.40 m³ ha⁻¹. Due to market restrictions, the actual amounts harvested were much lower: 96 trees were harvested with commercial boles totaling 2.7 m³ ha⁻¹. Of the total impact on biomass and carbon (above- and belowground), the logs removed from the area represented only 13.4%, while 86.6% was from losses in the forest as follows: 14.5% from the stumps, crowns, and roots of harvested trees (DBH ≥ 50 cm) plus 72.1% from the trees (DBH ≥ 10 cm) in the forest lost to roads, log landings, and skid tracks and the gap openings caused by felling the harvested trees. The estimated expenses exceeded the gross revenue of the management company (USD 519.15 ha⁻¹), a fact confirmed by the company’s subsequent bankruptcy. The project’s low harvest intensity reduces the environmental impact per hectare but increases the impact per cubic meter of wood harvested because producing a given volume of wood requires disturbing a larger area and because more kilometers of access roads and skid tracks have to be installed to extract a given volume of wood. Because many costs are fixed regardless of harvest intensity, small harvest volume can render such projects financially unfeasible, increasing the likelihood that they will be abandoned and not provide long-term “sustainable” forest protection. However, this does not mean that higher harvest intensity results in sustainability, as other constraints apply to high-intensity projects. We conclude that conservation alternatives to maintain the forest would be more beneficial than management for timber. Full article

Currently, there are several studies related to climate change, carbon sequestration, and floristic composition in different scenarios and land uses. In this context, the objective of this research is: (a) to characterize biodiversity based on ecological indicators and diversity indices and (b) to evaluate carbon sequestration in different components of chakra-type agroforestry systems and secondary tropical humid forests of the Ecuadorian Amazon. For this, temporary sampling plots of 1600 m² are established on the properties to be investigated. The study found that the structural characteristics and floristic composition vary according to the forest arrangement and the management system. Secondary forests are the most diverse, according to the Shannon (3.49), Simpson (0.96), and Margaleft (9.34) diversity indices, in addition to having the largest carbon stores with 233 (Mg C ha⁻¹), followed by agroforestry systems in association with timber trees (TAFS) and fruit trees (FAFS) with 97.8 and 95.1 (Mg C ha⁻¹) respectively, and cocoa monoculture (CMC) with 90.4 (Mg C ha⁻¹). These results demonstrate the importance of conserving the remnants of tropical forests that still remain, due to the diversity of species, ecosystem services, and the total carbon they contain, as well as the agroforestry systems (AFS), systems analogous to forests, which are gradually becoming important management systems, especially if they are associated with potential species to sequester carbon, such as those documented in this and several other studies that seek solutions to global climate change. Full article

Forest preservation and management are paramount for sustainable mitigation of climate change, timber production, and the economy. However, the potential of trees and forests to provide these benefits to the ecosystem is hampered by natural phenomena such as windthrow and anthropogenic activities. The aim of the current research was to undertake a critical thematic review (from 1983 to 2023) informed by a bibliometric analysis of existing literature on tree stability. The results revealed an increase in tree stability research between 2019 and 2022, with the USA, France, and Italy leading in research output, while Scotland and England notably demonstrated high research influence despite fewer publications. A keyword analysis showed that tree stability can be divided into four themes: tree species, architecture, anchorage, and environmental factors. Prominent studies on tree stability have focused on root anchorage. However, more recently, there has been a growing emphasis on urban forestry and disease-induced tree damage, underscoring a shift towards climate change and diversity research. It was concluded that considerable knowledge gaps still exist; that greater geographic diversification of research is needed and should include tropical and sub-tropical regions; that research relating to a wider range of soil types (and textures) should be conducted; and that a greater emphasis on large-scale physical modelling is required. Data and knowledge produced from these areas will improve our collective understanding of tree stability and therefore help decision makers and practitioners manage forestry resources in a more sustainable way into the future. Full article

Research highlights: Tropical forest restoration can be supported by the production of timber species in their understory. While they may appear at odds, they can be reconciled to promote environmental conservation and services. The lack of information on the management of tropical species causes a technical constraint for timber production in the understory of restoration sites, especially given the light restrictions. This issue could be amended with the development of methods to easily manage and estimate light availability, targeting management practices that balance restoration success and productivity. Materials and Methods: We conducted this study in an area within the Atlantic Forest, Brazil, where we tested the efficiency of chemical thinning to increase light availability in the understory of a five-year-old restoration planting, aiming to increase the growth rates of desirable timber species. Moreover, we tested the viability of using hemispherical photography taken with a smartphone to assess light incidence to assist restoration management practices. We calculated the percentage of photosynthetically active radiation (PAR) using a ceptometer in four different thinning intensities and compared them to the smartphone measures using correlation analysis. Results: Chemical thinning increased light incidence in the understory, with potential impacts on timber species productivity. Light management through PAR and canopy opening were highly correlated overall, especially after three months of management and 60% of thinning intensity. Conclusions: These findings demonstrate the potential for chemical thinning as a management practice to enhance light availability in the understory of tropical forest restoration sites. Additionally, our study highlights the value of using affordable and accessible tools like smartphones and fisheye clips for the indirect assessment of light conditions to promote natural regeneration and guide forest management and timber production in tropical forest restoration. Full article

In Neotropical regions, plantations and remnant forest populations of native trees coexist in a highly fragmented matrix and may be affected by isolation and reduction in population size, leading to genetic structure, inbreeding, and genetic bottlenecks that reduce the population’s genetic diversity. Tabebuia rosea variability in the Mayan Forest was studied by genotyping 30 trees from three plantations and three remnant natural populations using simple sequence repeats (SSRs) and inter-simple sequence repeats (ISSRs). H_o-SSR estimates were lower than H_e; the mean inbreeding coefficient was 0.07 and did not differ among populations, but was eight times higher in plantations than in remnant populations. Using ISSR data, the individuals were assigned to k = 5 and k = 4 clusters under admixture without and with geographic information used as priors in Bayesian analysis assignments. Genetic differentiation estimated with the Bayesian estimator II (0.0275 ± 0.0052) was significantly different from 0, but F_ST was not (0.0985 ± 0.1826), while paired F_ST among populations ranged from 0.05 up to 0.16. Only one remnant population displayed evidence of a genetic bottleneck. T. rosea displays a genetic structure in which the isolated remnant forest populations show moderate inbreeding levels. Full article