Forest Tree Species Research Articles

Phytohormones involved in vascular cambium activity in woods: current progress and future challenges

Vascular cambium is the continuation of meristem activity at the top of plants, which promotes lateral growth of plants. The vascular cambium evolved as an adaptation for secondary growth, initially in early seed plants, and became more refined in the evolution of gymnosperms and angiosperms. In angiosperms, it is crucial for plant growth and wood formation. The vascular cambium is regulated by a complex interplay of phytohormones, which are chemical messengers that coordinate various aspects of plant growth and development. This paper synthesizes the current knowledge on the regulatory effects of primary plant hormones and peptide signals on the development of the cambium in forest trees, and it outlines the current research status and future directions in this field. Understanding these regulatory mechanisms holds significant potential for enhancing our ability to manage and cultivate forest tree species in changing environmental conditions.

Unlocking the habitat suitability of wild olive to improve its industrial potential: A comprehensive distribution modeling study

Wild olive (Olea europaea L.) is a highly significant forest tree species, both in Türkiye and globally. Its oil and other extracts from the fruits and leaves are vital to various industries, including culinary, cosmetics, pharmaceuticals, and healthcare, making it a valuable non-timber forest product. However, its natural distribution is restricted to Mediterranean climates, emphasizing the need for conservation efforts to support its growth and expansion. Potential distribution modelling is one of the best studies to be done to protect a species and ensure its survival. In this study, the MaxEnt method, which relies exclusively on presence data, was used to generate a potential distribution map for wild olive. The environmental variables to be included in the modeling method were determined using the Analytic Hierarchy Process (AHP), one of the multi-criteria decision-making methods. From an initial set of 29 variables, AHP selected the top 11 for the final model. The resulting model demonstrated high accuracy, with an AUC value of 0.922, successfully identifying and mapping the potential distribution areas for wild olive across Türkiye.

3D-CNN with Multi-Scale Fusion for Tree Crown Segmentation and Species Classification

Natural secondary forests play a crucial role in global ecological security, climate change mitigation, and biodiversity conservation. However, accurately delineating individual tree crowns and identifying tree species in dense natural secondary forests remains a challenge. This study combines deep learning with traditional image segmentation methods to improve individual tree crown detection and species classification. The approach utilizes hyperspectral, unmanned aerial vehicle laser scanning data, and ground survey data from Maoershan Forest Farm in Heilongjiang Province, China. The study consists of two main processes: (1) combining semantic segmentation algorithms (U-Net and Deeplab V3 Plus) with watershed transform (WTS) for tree crown detection (U-WTS and D-WTS algorithms); (2) resampling the original images to different pixel densities (16 × 16, 32 × 32, and 64 × 64 pixels) and inputting them into five 3D-CNN models (ResNet10, ResNet18, ResNet34, ResNet50, VGG16). For tree species classification, the MSFB combined with the CNN models were used. The results show that the U-WTS algorithm achieved a recall of 0.809, precision of 0.885, and an F-score of 0.845. ResNet18 with a pixel density of 64 × 64 pixels achieved the highest overall accuracy (OA) of 0.916, an improvement of 0.049 over the original images. After incorporating MSFB, the OA improved by approximately 0.04 across all models, with only a 6% increase in model parameters. Notably, the floating-point operations (FLOPs) of ResNet18 + MSFB were only one-eighth of those of ResNet18 with 64 × 64 pixels, while achieving similar accuracy (OA: 0.912 vs. 0.916). This framework offers a scalable solution for large-scale tree species distribution mapping and forest resource inventories.

Different dry-wet pulses favor different functional strategies: A test using tropical dry forest tree species

In many terrestrial habitats, plants experience temporal heterogeneity in water availability both at the intra and inter annual scales, creating dry-wet pulse scenarios. This variability imposes two concomitant challenges for plants: surviving droughts and efficiently utilizing water when it becomes available, whose responses are closely interconnected. To date, most studies have focused on the response to drought following static designs that do not consider consequences of repeated transitions from one state to the other. In principle, different dry-wet pulse scenarios among years may differentially affect species performance, plant strategies, and promote coexistence through temporal niche separation. We predicted that short frequent droughts would disfavor drought-avoidant species, as rapid leaf loss and production could disrupt their carbon balance, whereas tolerant species, which maintain carbon gain during droughts, should thrive in such conditions. Prolonged droughts might harm tolerant species by causing severe cavitation. We assessed the survival and growth responses of seedlings from 19 tropical dry forest tree species to simulated natural dry-wet pulse scenarios, examining their relationships with the continuum of species’ functional strategies under field conditions, and used greenhouse experiments to accompany the field experiment. As expected, different dry-wet pulse scenarios favored different plant functional strategies. Contrary to predictions, the most tolerant outperformed the most avoiders under all drought scenarios, while rapid water-exploiters thrived under non-drought conditions. The superiority of tolerant over avoider species was reverted in the greenhouse, suggesting that in addition to physiology, the fate of species may depend on extrinsic factors as natural enemies. The interplay between the marked variability of dry-wet pulse scenarios across the years and the diversity of water use strategies may contribute to species coexistence in the tropical dry forests. This research is relevant in predicting changes in dominant tree species under future climate scenarios characterized by increased temporal variation in water availability.

A bHLH Transcription Factor Confers Salinity Stress Tolerance in Betula platyphylla.

Basic helix-loop-helix (bHLH) proteins comprise a large family of transcription factors that are involved in plant growth and development, as well as responses to various types of environmental stress. Betula platyphylla (birch) is a pioneer tree species in secondary forest that plays a key role in maintaining ecosystem stability and forest regeneration, but few bHLHs involved in abiotic stress responses have been unveiled in birch. In this study, nine BpbHLH TFs related to stress responses in the birch genome were identified. Quantitative real-time polymerase chain reaction (RT-PCR) analysis indicated that the expression of these TFs can be induced by salt stress, and the expression of BpbHLH1 was higher than that of other BpbHLH genes. Particle bombardment analysis revealed that BpbHLH1 was localized to the nucleus. Yeast transformation found that BpbHLH1 has transcriptional activation activity. We generated BpbHLH1-overexpressing and silencing transgenic birch plants and subjected them to salt stress analysis. BpbHLH1 can enhance the salt tolerance of birch plants by increasing the reactive oxygen species scavenging ability and inhibiting cell death. Yeast one-hybrid, ß-glucuronidase, and chromatin immunoprecipitation assays revealed that BpbHLH1 can regulate the expression of target genes involved in stress resistance by binding to the E-box-1, E-box-2 and G-box elements in their promoters. The results of this study enhanced our understanding of the salt tolerance conferred by BpbHLH TFs in B. platyphylla and identified useful genes for the breeding of novel birch germplasm.

Enrichment efficiencies of heavy metals in foliar litter of 72 evergreen and deciduous tree species in subtropical forests

Enrichment efficiencies of heavy metals in foliar litter of 72 evergreen and deciduous tree species in subtropical forests

Climate suitability for the moisture-sensitive conifer species may not be universally declining in a warming world

Amid ongoing and escalating climate change, understanding changes in habitat suitability for forest tree species is crucial for anticipating risks to their growth and ecosystem services. Despite advancements in this area, challenges remain, particularly in addressing spatial and temporal discrepancies in suitability change. This study evaluated habitat suitability changes for Qinghai spruce, a moisture-sensitive conifer species, during the warming period from 1960 to 2020, by integrating species distribution modeling with dendrochronological methods. Maxent model outputs revealed a distinct dipole pattern in habitat suitability changes: an increase in the west (56.2%) and a decrease in the east (43.8%). This dipole pattern was corroborated by the spatial pattern of forest population dynamics, highlighting much higher adult-tree mortality frequency, rate, and density decline in regions with decreased suitability, while showing minimal values in most (3 out of 4) regions with increased suitability. Climate factors and their changes explained 80.9% of the variance in suitability changes. Precipitation change, with a significant positive relationship to suitability changes, contributed the most (54.5%) to this explained variance, followed by post-warming temperature, which contributed 34.3% with a significant negative relationship. Thresholds of +20mm for precipitation change and 0°C for post-warming temperature distinguished regions with a high probability of increased suitability from those with a high probability of decreased suitability. This study provides nuanced insights into the responses of moisture-sensitive conifer species to climate change, helping inform and enhance conservation strategies for Qinghai spruce.

Group-selection system as alternative management of Scots pine (Pinus sylvestris L.) forests facing climate change

AbstractThe Scots pine (Pinus sylvestris L.) is economically and ecologically the most important forest tree species in Poland with its aerial share estimated at 59% and share in growing stock at 68%. Pine forests have been managed according to even-aged silviculture for decades, resulting in a simplified structure and increased vulnerability to climatic stress. Structurally simple forests also show low resilience and adaptability to the observed global changes. The growing awareness of the risks associated with global change is drawing particular attention to the need for alternative management of pine forests that meets the expectations of the public and foresters themselves. In 1992, an experiment with uneven-aged silviculture for pine forest was established in the Gubin Forest District (western Poland). Based on data collected from 49 permanent circular plots (size of 500 m2 each) covering approximately 30 ha of Scots pine forest, the effect of such silviculture on stand structure was analyzed. Dbh, total tree height, tree status, and tree coordinates (x, y) were measured on each plot. Measurements and observations were taken twice, in 1992 and 2019. Structural indices describing different aspects (size structure, vertical structure, spatial structure) were calculated. The dynamics of the stand structure were then analyzed over 27 years, during which the forest was managed under alternative management strategies. The results showed that group-selection cuttings promote strong differentiation of stand structure. The positive effect of such silviculture can be observed in each aspect of the stand structure. Together with other research findings, the results confirm the effectiveness of this alternative silviculture to diversify simplified pine forests to be better adapted to novel environmental conditions.

Experimental assessment of warming effects on the architecture and growth of the subalpine species Nothofagus pumilio

Abstract Global warming can pose a significant threat to forest tree species, particularly those inhabiting subalpine forests in temperate regions. Plasticity and adaptation are essential for the persistence of these forests. Nothofagus pumilio, the dominant tree species at the high-altitude limits of Patagonian temperate forests, is well adapted to cold conditions. To assess its potential responses to global warming, we established a genetic multi-environment field trial across three altitudes, 1200 (the current optimal for N. pumilio in North Patagonia), 800, and 400 m a.s.l., using plants from three provenances. Our hypothesis was that warmer conditions would reduce plant survival and promote the early expression of developmental attributes associated with advanced ontogenetic stages. After three growing seasons from trial planting, we measured survival, growth, and architectural traits. Plant survival and radial growth were lower at warmer, suboptimal sites. Warmer conditions induced the early expression of traits associated with advanced ontogenetic stages, particularly in two provenances, highlighting significant genotype-by-environment interactions. Additionally, plants at intermediate altitudes exhibited reduced height and a less hierarchical trunk structure, suggesting that juvenile growth and architecture in N. pumilio may be affected not only linearly with rising temperatures, but by interactions with stochastic factors, such as episodic frosts, which could operate on warming-induced effects decoupling plants from normal seasonality.

Influence of Soil Texture on Carbon Stocks in Deciduous and Coniferous Forest Biomass in the Forest-Steppe Zone of Oka–Don Plain

Forests play a crucial role in climate change mitigation by acting as a carbon sink. Understanding the influence of soil properties on carbon stocks in forests is essential for developing effective forest management strategies. The aim of the study was to assess the impact of soil texture on carbon stocks in the biomass of deciduous and coniferous tree stands of a forest-steppe ecotone. Soil samples were collected from 55 soil pits, and forest inventory data were obtained from eight permanent sample plots. The results showed that the distribution of mechanical particles in soils, particularly the stocks of silt and clay, significantly influenced the accumulation of carbon in tree stands. The stock of silt and clay was shown to increase with an increase in the diversity of tree species in forests and carbon stocks in forest stands. While soil organic carbon stocks did not exhibit a clear relationship with tree stand carbon stocks, a strong positive correlation (r = 0.802, p < 0.05) was found between the stocks of fine particles in the 2 m root-inhabited soil layer and the carbon stocks in tree biomass. The study provides a classification of forest types based on soil texture, which can facilitate differentiated forest management strategies for enhancing the carbon sequestration potential of forest ecosystems in the forest-steppe zone.

CONE YIELD AND GROWTH CHARACTERISTICS IN A PLANTATION OF CUPRESSUS SEMPERVIRENS

Mediterranean cypress (Cupressus sempervirens L.) is an important secondary forest tree species in Turkish forestry because of its high adaptation ability and resistance to different ecological condition. However, limited studies were carried out in cypress. In this study, cone numbers, tree height, diameters at breast height and at base were surveyed from 75 individuals chosen randomly at eighteen years’ plantation in the species. Interaction between number of cones and growth characteristics was estimated together with fertility variation and linkage parameters (i.e. population size) to contribute management and practices of seed collection and gene conservation areas, and other forestry practices of the species. Mean cone number was 86/tree ranged from 36 to 174. Individual trees had large differences for the growth traits, while means of tree height, diameters of breast height and base were 6.1 m, 9.9 cm, and 12.6 cm, respectively. Fertility variation was 1.15 (87% of total trees, CV%=38.9), which close to typical population. Positive and significant (p≤0.05) relations were found between growth characteristics and cone production in Cupressus sempervirens. Tree height was better predictor in cone production than diameters.

Interspecific association patterns of woody species in an evergreen broadleaved forest of Con Dao National Park, Vietnam

The interspecific associations among tree species in natural forest stands help to reveal mechanisms for maintaining species diversity and provide theoretical foundations for vegetation restoration and regeneration. This study focused on woody species within a 4-ha study plot established in an evergreen broadleaved forest in Con Dao National Park, Vietnam. We analyzed the interspecific associations among sixty-four recorded woody species in the study plot based on their presence and absence in subplots at two sampling scales: 10 m × 10 m and 20 m × 20 m. The results indicated that most of the 3,969 pairs of the sixty-four species exhibited independent associations, confirming an individualistic hypothesis proposed by Gleason. Furthermore, species interactions of common species were stronger than those of rare ones, indicating that species abundance influenced interspecific associations, and this result acknowledges the presence of random processes in driving species coexistence. A comparison of observed communities and random communities based on null models revealed that deterministic processes play a dominant role in governing species co-occurrence within the tree communities in the study area. Our study provides insights into the complex dynamics of species interactions within forest ecosystems, contributing to our understanding of biodiversity maintenance and offering valuable guidance for conservation and restoration efforts.

Innovative reconstruction and evaluation of forest refinement datasets by combining multi-source data: A case study of Guangdong Province

The acquisition and monitoring of forest cover data are crucial for ecological protection, resource management, and climate change research. However, relying on a single data source provides limited data accuracy and does not adequately capture the forest structure and functional attributes. We combined six commonly land cover datasets and forest age, canopy height, above-ground biomass, and tree species distribution datasets to reconstruct 30 m spatially accurate forest refinement dataset (FRD) for Guangdong Province. In addition, the distribution characteristics of forest structure and function were evaluated using forest morphological spatial pattern analysis. The results show that the overall accuracy of FRD of the Guangdong Province in 2020 reached 86.07 %. Forest types in the Guangdong Province were mainly dominated by evergreen needle-leaf forests. Tsuga chinensis, Red cedar, and Pinus sylvestris were more commonly planted. Older and taller trees were found in northern and eastern Guangdong. In addition, forest above-ground biomass (AGB) was larger in the coastal areas of northern and western Guangdong. The core and perforation had the oldest age and the highest tree height, and the islet had the lowest for all forest structure and function indicators. Based on multi-source datasets, this study contributes to a better understanding of the attributes characterizing the structure and function of forests. The refined dataset and research framework will effectively enhance forest management efficiency and policy making, as well as provide case references for research on climate change response, forest conservation and biodiversity assessment.

The influence of tree species on small scale spatial soil properties and microbial activities in a mixed bamboo and broad-leaved forest

Soil enzyme activity and microbial biomass play a critical role in myriad ecological processes. Bamboo and broad-leaved mixed forests have received widespread attention as important forestry models for ecological restoration and sustainable development; however, our understanding the influences of broad-leaved tree species in mixed bamboo forests on soil properties and microbial activity remains unclear. Here we sampled twenty-seven spatially interspersed stands of bamboo-Castanopsis chinensis Hance mixed forest (CCB), bamboo-Alniphyllum fortune (Hemsl.) Makino mixed forest (AFB), and bamboo-Choerospondias axillaris mixed forest (CAB), with different mixing ratios (0–10 %, 10–20 %, 20–40 % canopy proportions) in subtropical China, to examine the effects of tree species and mixed ratio on soil nutrients, microbial biomass, and enzyme activity. We found that the different forests exhibited variations in soil nutrient levels. CAB forests exhibit notably higher mean C, N, and P contents than AFB and CCB, particularly at a 10–20 % mixing ratio where SOC concentration reached 46.50 g/kg. CAB forests demonstrated significantly higher activities of invertase (mean 701.83U/g), urease (8393.44U/g), and catalase (501.73U/g) compared to AFB and CCB forests, with peak enzyme activities observed at a 10–20 % mixing ratio. Soil microbial biomass C and N were notably greater in CAB and CCB forests than in AFB forests. CAB forests also exhibited the highest soil microbial biomass P (mean 48.68 mg/kg), which rose consistently with an increased mixing ratio. Multiple factor analysis revealed that the enzyme activities were significantly correlated with the annual growth of fine roots in the forest and were positively correlated with resident C, total N, total P, C: N, and C: P. Overall, the results provide insights into the importance of tree species and crown size in bamboo and broadleaved tree mixed forest in soil features and the microbial activity while providing management guidance for the selection of mixed tree species for sustainable management of bamboo forest soil microenvironment.

Above and belowground functional trait response to biochar addition in seedlings of six tropical dry forest tree species

Above and belowground functional trait response to biochar addition in seedlings of six tropical dry forest tree species

Stable isotope analysis indicates partial mycoheterotrophy in arbuscular mycorrhizal woody seedlings in tropical forests

Abstract Chlorophyllous plants exhibiting partial mycoheterotrophy obtain carbon through mycorrhizal interactions in addition to photosynthesis. In arbuscular mycorrhizal (AM) plants, the Paris‐morphotype (i.e. hyphal coils) is considered essential for mycoheterotrophic carbon gains. Numerous tree species in tropical lowland forests form this morphotype, and under light‐ and nutrient‐limitation, additional carbon gain would be beneficial. However, if seedlings of woody species in the understory of tropical lowland forests exhibit partial mycoheterotrophy remains unexplored. Here we (a) examined the AM morphotype (Paris‐ or Arum‐type) in seedlings of 41 tropical woody species, and (b) to determine if any of the target Paris‐type species are partially mycoheterotrophic, we compared their multi‐element stable isotope natural abundance (13C, 2H, 18O, 15N) with neighbouring autotrophic non‐Paris‐type reference seedlings. About 50% of the investigated species (and 80% of the genera) exhibited the Paris‐type, expanding the number of tropical plant genera with Paris‐type AM. Enrichment in 13C, but not in 18O in target compared with neighbouring reference plants indicated partial mycoheterotrophy in seedlings of 6 of the 21 investigated Paris‐type AM species. Our results indicate for the first time that carbon gain through mycoheterotrophy occurs in seedlings of AM tropical tree species. In tropical forests, partial mycoheterotrophy during seedling establishment may confer so far unrecognised ecological advantages influencing seedling recruitment and ecosystem dynamics. Read the free Plain Language Summary for this article on the Journal blog.

Effects of tree species composition in plantation forest on soil aggregate stability and organic carbon pools in northeastern China

Forest tree species composition influences soil aggregate stability (SAS) and labile organic carbon (LOC) components, which may affect soil organic carbon (SOC) sequestration. Despite the general belief that mixed forests enhance SOC storage, evidence suggests that certain monocultures may outperform mixed forests. Therefore, information on the specific impact of tree species mixing on SOC through SAS and LOC remains limited. This study aimed to investigate the effects of tree species composition on SAS and LOC in 49-year-old monoculture (Larix gmelinii (Lg), Pinus koraiensis (Pk)) and mixed conifer-broadleaf (Larix gmelinii - Fraxinus mandshurica (LF), and Pinus koraiensis - Populus ussuriensis (PP)) stands, and its impact on SOC sequestration. We measured SAS indices (including mean weight diameter (MWD), geometric mean diameter (GMD), and > 0.25 mm water stable aggregate proportion (WSA)), SOC storage, and LOC components (easily oxidized organic carbon (EOC), microbial biomass carbon (MBC), and dissolved organic carbon (DOC)) in 0–40 cm soil horizons during the growing season (June, August, and October). Our results showed that tree species composition significantly influenced SAS and SOC components, with the highest SAS found in the 0–20 cm soil horizon in Pk and PP forests (p < 0.05) (Jun.: MWD Pk: 0.98, GMD Pk: 1.88, WSA Pk: 1.79, MWD PP: 0.98, GMD PP: 1.90, WSA PP: 1.81; Aug.: MWD Pk: 0.99, GMD Pk: 1.85, WSA Pk: 1.77, MWD PP: 0.99, GMD PP: 1.89, WSA PP: 1.81; Oct.: MWD Pk: 0.98, GMD Pk: 1.86, WSA Pk: 1.76, MWD PP: 0.97, GMD PP: 1.83, WSA PP: 1.73) and the highest SOC components in the LF stand (p < 0.05) (soil horizon 0–20 cm: Jun.: SOC: 110.23 g/kg, EOC: 92.81 g/kg, MBC: 1418.39 mg/kg, DOC: 1090.01 mg/kg; Aug.: SOC: 108.46 g/kg, EOC: 79.57 g/kg, MBC: 1369.91 mg/kg, DOC: 1316.11 mg/kg; Oct.: SOC: 109.78 g/kg, EOC: 44.37 g/kg, MBC: 1782.6 mg/kg, DOC: 671.05 mg/kg). Correlation analysis revealed significant relationships between SOC and LOC components (p < 0.05, r EOC = 0.43, r MBC = 0.46, r DOC = 0.17) but not associated with SAS (p > 0.05, r MWD = −0.07, r GMD = −0.07). Tree species composition in plantation stands significantly affects SAS and SOC pools. In conclusion, the positive effect of mixed coniferous and broad-leaved forests on SAS and SOC pools is also contingent upon the tree species identity. The results suggest that targeted selection of tree species could better enhance SAS and SOC pools in plantation than a mere increase in species richness.

Effects of Biochar and Nitrogen Fertilizer Application Ratio on Leaf Physiology and Soil Characteristics of Bambusa tuldoides ‘Swolleninternode’

As one of the main bamboo species in coastal sandy land protection forests, Bambusa tuldoides ‘Swolleninternode’ can effectively improve the structure of forest tree species, increase the diversity of tree species and enhance the protection efficiency. However, research on the cultivation and utilization of B. tuldoides is still relatively scarce. Therefore, in this study, B. tuldoides was used as the research object. By applying biochar and nitrogen fertilizer, the effects of different biochar and nitrogen fertilizer ratios on the physiology and soil characteristics of bamboo were analyzed, and the optimal ratio scheme was identified. The results showed that the ratio of the T5 (A2B2C3) treatment had the best effect on the total chlorophyll, non-structural carbohydrate and nutrient contents of B. tuldoides leaves, and the contents under treatments was generally higher than under the control, CK. The activities of soil invertase, nitrate reductase and nitrite reductase were significantly increased under biochar treatment, and the effects of the T5 treatment were the best. The results of principal component analysis showed that the absolute values of the coefficient of leaf potassium, phosphorus content and soil total nitrogen were larger and more important, and the comprehensive evaluation of the T5 treatment was the highest.

A practical framework for applied forestry assisted migration

Recent and projected changes in climate over this century pose an unprecedented threat to the health, diversity, and productivity of forest ecosystems. Forests have migrated and adapted to long-term changes in climate over thousands to millions of years; however, natural migration rates and adaptive responses of tree populations cannot match the rapid pace of current climate change. Consequently, more climate-informed approaches to reforestation are needed as current reforestation strategies using local seed sources may no longer be adequate to meet forest management objectives. Assisted migration is a climate change adaptation technique that can help maintain the ecosystem services and economic value that forests provide. Forestry assisted migration (FAM) focusses on the movement of populations of widespread, commercially, or ecologically important forest tree species within or just beyond their current ranges as a way to maintain forest productivity and health in the face of climate change. Although the forestry community recognizes FAM as a reforestation tool, guidance for planning and implementation of FAM is lacking and a framework that provides this guidance can prove useful to land managers with limited time and resources available who want to undertake FAM. We developed a practical framework (the FAM Framework) to provide a structured approach to ensure the most important considerations and best available science are utilized by land managers wanting to implement FAM on their land base. The FAM Framework incorporates multiple factors for the application of FAM in four sequential phases: assessment and analysis, climate-based plant material selection, seed procurement and deployment, and documentation and monitoring. The FAM Framework was tested by developing an assisted migration plan for the Superior National Forest, Minnesota (MN), and lessons learned from the development of this specific plan were used to revise and improve the FAM Framework for suitability across all lands. While originally designed to meet the needs of National Forest System land managers, it is relevant and applicable across the spectrum of land ownership because it incorporates consideration of critical elements in planning and implementing FAM on any landscape while facilitating adaptive management for active learning and future implementation.

Long‐Term Impacts of Selective Logging in a Tropical Rainforest in the East Region of Cameroon

ABSTRACTAlthough selective logging has become the primary cause of degradation in many African countries, little is known about its long‐term effects. This study investigated the long‐term effects of selective logging on forest tree species diversity and dynamics in the East Region of Cameroon. Six permanent monitoring plots of 1 ha each in unlogged and logged forests were established in 2005 and a recensus in 2011. Each 1 ha plot was divided into 25, 20 × 20 m quadrats. Each 20 × 20 m quadrat was further divided into 16, 5 × 5 m subquadrats, where the diameter at breast height (DBH) of all trees ≥ 2 cm was measured. There was a decrease in plant species density and richness in all forest types. Sloetiopsis usambarensis was the most important species in the unlogged forests and forests logged 21 years ago. The most important family was Putrangivaceae, Euphorbiaceae and Violaceae in the unlogged forests and forests logged 11 and 21 years ago, respectively. The frequency distribution of stem size classes indicated a reversed J‐shape of tropical forests. The above ground biomass (AGB) recovered more than 50% in all forests, and the unlogged forest had the highest AGB (961.8 Mg/ha). Larger stems indicated a forest at a stage of recovery from disturbance. Silvicultural management should be considered.