Forest Species Research Articles

Antibacterial activity of the biogenic volatile organic compounds from three species of bamboo

Plant biogenic volatile organic compounds (BVOCs) possess ecological functions in antimicrobial benefits and air purification. The objectives of the study were to determine the differences in antimicrobial capacity of bamboo forests at different sampling sites. Three common bamboo species—Phyllostachys edulis, Bambusa emeiensis, and Phyllostachys violascens—were selected to determinate the antimicrobial activity of bamboo forests as well as under ex vivo conditions. Natural sedimentation method was used to determine the microbe counts in bamboo forests, and the microbe counts in grassland in the same area was measured as control treatment. The results showed that except for the P. violascens in Ya’an, the airborne microbial content of the sampling sites in bamboo forests was significantly lower relative to that of grassland in the same area, and inhibition rate reached 74.14% in the P. violascens forest in Dujiangyan. P. edulis forest and P. violascens forest in Ya'an had significantly lower inhibition rates than the other sampling sites, and there was no significant difference in the inhibition rates among the rest of the bamboo forest. The bacterial inhibition rate of bamboo leaves under ex vivo conditions varied with bamboo species and bacterial strains, with higher antibacterial activity against Gram-negative bacteria overall. Escherichia coli was sensitive to B. emeiensis leaves, while Staphylococcus aureus and Bacillus subtilis were sensitive to P. violascens leaves. Moreover, Candida albicans, S. cremoris, and Shigella Castellani were sensitive to P. edulis leaves. An analysis of the BVOCs composition from P. edulis collected in Changning by SPME-GC/MS revealed that the relative content of ocimene was obviously higher than other components. This study showed that P. edulis BVOCs have strong inhibitory ability to the tested microorganisms, and its main constituent, ocimene, has health benefit. P. edulis has the potential to become a forest recreation bamboo species.

Natural Feed Options for Sumatran Elephants at the Seblat Elephant Training Center North Bengkulu Regency, Indonesia

The health and welfare of Sumatran elephants at the Seblat Elephant Training Center (SETC), North Bengkulu Regency, depend on many environmental factors in their habitat, one of which is the availability of a variety of plant species (diet) in the Seblat Nature Tourism Park (SNTP) forest area. Research on this matter was conducted in May-June 2022 within the SNTP forest area, where the Seblat SETC facility is located. This study aimed to evaluate the dietary preferences of Sumatran elephants at SETC towards natural plant species in the SNTP forest. The "Focal Animal Sampling" method was used to measure the duration of feeding activity of each elephant on specific plant species while they were foraging in the forest. The elephants' preferences for plant species were analyzed quantitatively, while the types of plants consumed by the elephants were described qualitatively. The research found that 15 families with 33 species were identified as the natural food plants for the SETC elephants in Bengkulu. The Poaceae family was most preferred by the elephants with the highest preference value (35.07%), followed by Fabaceae (31.73%), Malvaceae (9.87%), and Cyperaceae (7.83%), while the least preferred were Costaceae, and Myrtaceae (0.33% respectively), Convolvulaceae (0.41%), and Selaginellaceae (0.73%). Based on sex, adult male elephants preferred Fabaceae plants such as Mimosa pudica (35.99%), Desmodium triflorum (11.66%), Mimosa invisa (7.36%), Cynodon dactylon (6.54%) over other families. Conversely, adult female elephants preferred Poaceae such as Leersia virginica Willd., Cyrtococcum patens (L.) A., Centhotheca lappacea Desvaux., Digitaria sanguinalis (L.) Scop., and Imperata cylindrica L. patients. These predictors, however, need further work to validate reliability.

Linalool and 1,8-Cineole as Constitutive Disease-Resistant Factors of Norway Spruce Against Necrotrophic Pathogen Heterobasidion Parviporum.

Norway spruce is an important coniferous species in boreal forests. Root and stem rot diseases caused by the necrotrophic pathogen Heterobasidion parviporum threaten the wood production of Norway spruce which necessitates the search for durable control and management strategies. Breeding for resistant traits is considered a viable long-term strategy. However, identification of potential resistant traits and markers remains a major challenge. In this study, short-term disease resistance screening was conducted using 218 Norway spruce clones from 17 families. Disease resistance was evaluated based on the size of necrosis lesion length following infection with the pathogen. A subset of needles/branches from clones with small (partial resistant) or large (susceptible) lesions were used for terpene analysis and transcriptomic profiling. The results revealed that the content of monoterpene linalool and 1,8-cineole and their respective encoded genes were significantly more abundant and highly expressed in the partial resistant group. Furthermore, linalool and 1,8-cineole were demonstrated to have inhibitory effect on the growth of the pathogen H. parviporum, with morphological distortion of the hyphae. RNAseq analysis revealed that transcript of pathogen genes involved in the regulation of carbohydrate metabolism and stress responses were significantly decreased in presence of the terpenes. The results suggest the relevance of monoterpenes together with jasmonic acid precursor and some genes involved in phenylpropanoid biosynthesis, as constitutive tolerance factors for Norway spruce tolerance against necrotrophic pathogen. The high level of necrosis related cell death gene expression might be factors critical for host susceptibility and disease development.

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.

Characteristics of soil organic carbon fractions and influencing factors in different understory mosses in karst urban parks.

The impact of different vegetation types on soil organic carbon (SOC) is a key focus in global warming research. Bryophytes, commonly found in karst urban forests, significantly contribute to carbon accumulation in surface soil. However, the changes in soil organic carbon fractions under moss and the influencing factors remain unclear. To address this knowledge gap, the study examined the organic carbon content, soil physicochemical properties, and associated environmental factors in both moss-covered soil and bare soil under six different forest species within an urban park. The results showed that the SOC contents under moss cover in evergreen coniferous forest (127.28g/kg), bamboo forest (144.70g/kg), deciduous broad-leaved forest (87.63g/kg), and evergreen shrub (109.28g/kg) were significantly higher compared to bare soil. Moss cover also had a significant impact on soil readily oxidizable carbon (ROC), particulate organic carbon (POC), mineral-associated organic carbon (MOC), and heavy fraction organic carbon (HFOC) (P < 0.01). The soil under moss had a higher content of stable organic carbon fraction, which is conducive to the stability of the soil organic carbon pool. The interaction between moss cover and stand type had the most significant effect on soil organic carbon, especially in bamboo forests. Canopy density, moss biomass, and soil moisture were the main environmental factors affecting the content of soil organic carbon and its fractions, while soil organic carbon content was mainly affected by soil nitrogen and phosphorus. This study establishes a theoretical framework for investigating the carbon cycle in karst urban underforest ecosystems, offering a scientific basis for the management and preservation of urban green space ecosystems. Future studies should include bryophytes in the assessment of dynamic factors affecting the soil carbon pool under forest cover and further explore the function and ecological significance of bryophytes in understory ecosystems.

Correlation between Woody Species and Environmental Variables in a Tropical Forest in Central Laos

The tropical forest biome serves as a significant focal point for conservation endeavors. However, understanding the variations in woody plant composition and the underlying driving factors remains limited. The vegetation gradient within Phou Khao Khouay (PKK) National Park in central Laos presents an intriguing environmental model for investigating these patterns. This study, conducted within PKK National Park, aims to classify woody plant communities of three different forest types: mixed deciduous forest (MDF), dry evergreen forest (DEF), and mixed coniferous forest (MCF), utilizing both the phytosociology approach and multivariate analysis. Data from 32 permanent plots (each measuring 50 m × 50 m) were analyzed, revealing 5,477 tree individuals with a diameter at breast height (DBH) ≥ 5 cm, representing 194 woody species from 64 families and 133 genera. The results indicate significant diversity at the family and genus levels, identifying four distinct plant communities and 44 indicator species based on Tichy and Chytry's phi coefficient method. Stability characterizes the MCF forest type, while the stands of DEF and MDF exhibit differentiation into three communities each. Notably, high heterogeneity in species composition and environmental conditions is evident, with elevation and soil nutrient levels (specifically total phosphorus and total potassium) emerging as primary influencers on species coexistence. The study also highlights correlations between woody plant species composition and topographic and soil variables. These findings underscore the importance of identifying microhabitats conducive to growing and conserving woody plant species within PKK National Park for future research and conservation efforts.

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.

Tree traits are a stronger predictor of bee traits and species richness than taxonomic diversity

Abstract Functional traits help to understand biological diversity and the mechanism by which ecological communities are structured and how they respond to the environment. For example, the high tree species diversity within tropical forests can be grouped into a few functional attributes, wood density, size and dependence on animal pollination or seed dispersal. However, little is known about how these traits influence animal taxonomic and functional diversity in the forests. We carried out a vegetation census on six plots (20 × 100 m) within the National Forest of Carajás (Amazon biome) to identify forest canopy species and their functional traits. Within the same plot, we also applied three bee sampling methods (entomological nets, honey traps and scent traps). By characterizing the functional traits of trees and bees, we were able to predict bee functional diversity better than with taxonomic diversity alone via combinations of tree traits like size, wood density, dependence on pollinators and extinction risk. We found that larger trees with low wood density were negatively associated with small, eusocial tree cavity nesting bees. The richness and abundance of trees with high extinction risk was positively associated with the richness of medium‐sized solitary bees. The dominance in the community of pollinator‐dependent trees (average diameter in the basal area) was negatively associated with the richness of above‐ground and cavity nesting bees. Our findings suggest that the composition of the tree community limits the availability of nesting resources for specific groups of bees. Moreover, the presence of trees with higher extinction risk (conservation value) was associated with a greater variety of bee traits and was the only metric associated with overall bee richness. As expected, functional traits shed light on the mechanism that might drive high diversity within tropical forests. In addition, there appears to be complementarity in terms of conservation value and carbon stock potential, as areas that habour tree species with higher extinction risk and higher wood density are also those with overall greater bee and functional diversity. Finally, our study can contribute to the restoration of plant—pollinator community by providing an understanding of the vegetation community that contributes to biodiversity maintenance. Read the free Plain Language Summary for this article on the Journal blog.

Essential steps for establishing a large‐scale passive acoustic monitoring for an elusive forest bird species: the Eurasian Woodcock (Scolopax rusticola)

In light of global biodiversity loss, comprehensive monitoring of species and biodiversity is fundamental for effective conservation management. Technology‐driven approaches, particularly in the field of bioacoustics, have gained importance, with autonomous recording units (ARUs) such as the AudioMoth being a notable example. However, a systematic application of this technology in large‐scale passive acoustic monitoring (PAM) schemes is challenging because of a lack of species‐specific calibration techniques and information on survey design. Using Eurasian Woodcock Scolopax rusticola as our focal species, we present application‐oriented guidelines for testing and implementing a terrestrial, single‐species PAM scheme. In this process, we assessed the species‐specific detection space of AudioMoths, considering the influence of recording setup and location. ARUs had similar detection rates as a human observer when set up in locations with low vegetation. A further comparative analysis of bioacoustic and traditional roding surveys confirmed the comparability of the two methods. The last step comprised an evaluation of BirdNET as a means of automated species detection. Although BirdNET reliably detected Woodcock occurrence, our results underline the need for rigorous testing of computer‐aided data analysis as well as recording hardware before establishing PAM. We demonstrate that low‐cost open source ARUs and open access analysis tools can yield results on a par with traditional survey methods, and we provide specific recommendations for PAM for Eurasian Woodcock.

Population trends of the Cape Parrot Poicephalus robustus in the Amatholes, Eastern Cape: trialling ground-based flock photography for demographic and health assessment

Globally, 60% of species in the order Psittaciformes are experiencing population declines. Understanding demographic and health trends in populations is vital for the prioritisation of limited conservation resources. The Cape Parrot Poicephalus robustus is a South African endemic forest species that is endangered by habitat degradation and Psittacine Beak and Feather Disease (PBFD). In the Amathole region of the Eastern Cape province, Cape Parrots gather in large numbers every autumn to feed at a particular orchard of Pecan trees Carya illinoinensis. This annual event is an opportunity for researchers to assess trends in a population that does not otherwise typically form large flocks. We used a novel, non-invasive method of flock photography analysis between 2017 and 2022 to assess the demographics and PBFD symptoms of the population. A mean of 439 ± SD 127 Cape Parrots visited the orchard on the peak day each year, with 1.2 males per female and 3 adults per juvenile overall. Proportions of juveniles fluctuated between extremes of 70% in 2019 and < 4% in 2020. PBFD symptoms increased markedly in the food-scarce year of 2019, with a gradual recovery seen in the years following. Roosting numbers were also tracked monthly from 2018 to 2022 to indicate local population fluctuations in the study area around Hogsback. An average of 112 ± SD 31 Cape Parrots roosted there, with roost counts notably higher from January to June, bolstered by newly-fledged juveniles prior to their dispersal. This study demonstrates the use of flock photographs as an effective, non-invasive tool to assess the demographics and health of an avian population.

Etiology of Pine Ghost Canker in Southern California Urban Forests.

Pine ghost canker is a recently described disease affecting multiple pine species in urban forests of Southern California. Symptoms include wedged cankers with irregular margins and cryptic discoloration on cross-sections of branches, which can lead to severe dieback and potentially tree death. In this study, we identified and characterized five Neofusicoccum species (N. luteum, N. mediterraneum, N. parvum, N. stellenboschianum, and N. vitifusiforme) as the primary etiological agents of pine ghost canker. These pathogens were consistently isolated from multiple symptomatic pine samples (n = 41) and identified by morphology and phylogenetic analyses using four DNA barcodes (rDNA ITS, tef1, tub2, and rpb2). Pathogenicity was confirmed on healthy branches of 15-year-old Monterey pines, where the five Neofusicoccum species, caused vascular lesions that were not significantly different in length. Secondary fungi (Diaporthe, Diplodia, Neopestalotiopsis, and Pestalotiopsis spp.) were also recovered from symptomatic tissues but did not cause vascular lesions in pathogenicity tests. The optimal temperature for mycelial growth of N. luteum and N. parvum was 30 °C, whereas for N. mediterraneum, N. stellenboschianum and N. vitifusiforme, it was 25 °C. All five species were able to resume growth at room temperature (20 °C) after showing no growth during a 7-day exposure to 5 °C and 40 °C. This study constitutes the first report of N. luteum, N. stellenboschianum, and N. vitifusiforme causing pine ghost canker in California. Environmental factors such as warmer temperatures, irrigation, and pest infestations are discussed as drivers of disease expression in pine trees. Management practices are also proposed.

Survey-based inference of continental African elephant decline

Long-term quantification of temporal species trends is fundamental to the assignment of conservation status, which in turn is critical for planning and targeting management interventions. However, monitoring effort and methodologies can change over the assessment period, resulting in heterogeneous data that are difficult to interpret. Here, we develop a hierarchical, random effects Bayesian model to estimate site-level trends in density of African elephants from geographically disparate survey data. The approach treats the density trend per site as a random effect and estimates a parametric distribution of these trends for each partitioning of the data. Data were available from 475 sites, in 37 countries, between 1964 and 2016 (a total of 1,325 surveys). We implemented the model separately and in combination for the African forest (Loxodonta cyclotis) and savannah (Loxodonta africana) elephant species, as well as by region. Inference from these distributions indicates a mean site-level decline for each species over the study period, with the average forest elephant decline estimated to be more than 90% compared to 70% for the savannah elephant. In combination, there has been a mean 77% decline across all sites; but in all models, substantial heterogeneity in trends was found, with stable to increasing trends more common in southern Africa. This work provides the most comprehensive assessment undertaken on the two African elephant species, illustrating the variability in their status across populations.

Relationship Between Age and Condensed Tannin Content in the Bark of Two Forest Species Grown in Northeast Brazil

Objective: This research aimed to evaluate the influence of tree age on the condensed tannins content in the bark of two forest species. Theoretical Framework: Tannins are phenolic compounds present in various parts of plants and have consolidated applications in the market. This way, silvicultural studies of different species with the potential to produce are relevant. Method: Barks of Azadirachta indica at 5, 6, and 7 years and Mimosa caesalpiniaefolia at 6, 7, and 9 years were collected from an experimental plantation located in a forest area in Rio Grande do Norte, Brazil. The barks were then air-dried and ground to obtain a material subjected to extraction. Total solids content, Stiasny index, and condensed tannin content were determined from the hot-water extracts. Results and Discussion: The condensed tannins content in A. indica bark did not vary as tree age increased, while for M. caesalpiniaefolia, the most productive age was determined to be six years old. Research Implications: The experimental approach showed that A. indica presented stable tannin content in the bark regardless of age, allowing continuous and flexible management to produce these extractives. In contrast, M. caesalpiniifolia presented condensed tannins, with their reactivity decreasing with age, indicating that younger trees are more suitable for high-quality extractions and commercial production. Originality/Value: Tannins content in Azadirachta indica bark remains stable over time, facilitating continuous management and Mimosa caesalpiniifolia bark, the concentration of tannins is higher in younger trees.

Selection of Superior Clones of Cedrela odorata L. at Early Age in an Asexual Seed Orchard for Genetic Improvement

The selection of plant age in forest species is crucial in a genetic improvement program, as time is a key factor in decision-making. This study aimed to evaluate the variation in clonal growth of Cedrela odorata L. to identify clones with superior performance at an early age. The orchard was established in September 2014, utilizing a completely randomized block design with a planting distance of 4 x 4 m. The experiment comprised 70 clones (ortets), each with 35 replicates (ramets), totaling 2,450 ramets. Selection was based on four key traits: total height (th), clear stem height (csh), normal diameter (nd), and crown diameter (cd). These variables were used to calculate the percentage gain or loss in performance for each clone relative to the population mean. A principal component analysis, analysis of variance (ANOVA), Tukey test (p≤0.05), and cluster analysis were performed to assess the data. The results identified 16 out of the 70 clones as having superior traits. The superior clones included 53-CoSFcoChan07, 2-CoGua344, 15-CoB191, 19-CoKal126, 22-CoKal142, 41-CoTux558, 35-CoTez642, 56-CoTez539, 45-CoTez549, 49-CoTez540, 50-CoTez540, 59-CoTux555, 62-CoCar5, 30-CoBac02, 48-CoTez544, and 10-CoKal16. The average traits of these superior clones were 8.0±0.4 m for total height, 2.6±0.1 m for clear stem height, 0.13±0.0 m for normal diameter, and 4.1±0.2 m for crown diameter, representing a 15% increase over the population mean.

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.

The effect of ontogeny, competition, site, and climate on background mortality for trees of nine species in Canadian boreal forest.

Background tree mortality can be defined as the death of trees that naturally occurs as stands develop, in the absence of major or sudden stand disturbances. The phenomenon is often linked to ontogeny and competition and generally affects individual trees, unlike catastrophic mortality, which affects most trees in the stand. To forecast stand characteristics and to estimate how stand development could change in response to changing climate, it is necessary to quantify background mortality and to identify the most important factors involved. Using data from 10,045 permanent sample plots, we modeled background tree mortality for the 9 most abundant tree species of the eastern Canadian boreal forest. We used explanatory variables related to stand and tree ontogeny, competition, site characteristics and climate to calibrate the models. We found that an increase in age, competition and the presence of partial cut increased the mortality risk. However, the effect of DBH and site-related variables varied among species. We also found that higher temperatures, less precipitation, and higher aridity index values increased background tree mortality. According to mortality simulations under different future climate scenarios, background tree mortality could increase in the next decades for 6 of the 9 tree species studied.

In splendid isolation: a new cloud forest species expands the distribution of Myrceugenia (Myrtaceae) into Las Yungas and adds a new genus to the flora of Bolivia

Myrceugenia is a temperate or subtropical genus of c. 50 species with a disjunct distribution across South America. The ‘western’ species occur in central Chile and north-western Argentina with one species in the Juan Fernández Islands. The ‘eastern’ species occur in Uruguay, southern Brazil, and marginal regions of Argentina and Paraguay, reaching montane eastern Brazil (two isolated taxa in Central Brazil). It is hypothesized that Myrceugenia once grew across the temperate forests of southern South America, but that oceanic transgressions and the elevation of the Andes during the Miocene divided its populations as the forests retracted from the centre of the continent. The Las Yungas floristic province is a strip of cool, temperate forest that runs along the eastern slopes of the Andes from Venezuela to northern Argentina; Myrceugenia was not known to occur there. We report the discovery of a new species of Myrceugenia in southern Las Yungas (Bosque Tucumano Boliviano). It is distinct from all other species of the genus by the combination of solitary flowers, sub-ancipitate hypanthium, bilocular locules, and 12-13 clustered ovules. The phylogeny of Myrceugenia shows geographic structuring with three basal western clades and one derived eastern clade. The isolated taxa of Myrceugenia from Central Brazil were sisters, respectively, to the rest of the eastern clade and to one of its two subclades, suggesting that isolated taxa are relictual. The discovery of this species has made Myrceugenia the only genus of Myrtaceae to grow in the three cool, humid forests of southern South America.

Landscape degradation drives metal bioaccumulation in bats from Atlantic Forest cacao region, Brazil.

Agricultural landscapes worldwide are heavily sprayed with agrochemicals to increase crop productivity. These agrochemicals release bio-accumulative pollutants such as heavy metals that often persist in the environment with harmful impacts on biota. In a prime endangered Atlantic Forest biome, in Bahia, Brazil, agroforestry of cacao (Theobroma cacao) provides a livelihood for small farmers and suitable habitats for forest species. However, landscape transformation to pasture and monoculture expose vulnerable communities to scarcely evaluated pollutants with unknown effects on the health of humans and animals. We assessed the bioaccumulation of manganese (Mn), lead (Pb), and copper (Cu) by analyzing hair samples of 326 bats representing 28 species across 15 cacao agroforestry and 2 forest remnants. Bats from regions heavily disturbed by pastures and monocultures showed higher levels of Pb (41.20µg/g) and Mn (0.44µg/g) compared to those from areas where forest or cacao agroforestry dominates the landscape. Local grassland covers increased Pb bioaccumulation, while forest cover reduced it. Cacao agroforestry appeared to increase Cu exposure, likely due to fungicide use. This study pioneers the evaluation of heavy metal accumulation in bats inhabiting cacao agroforestry and Atlantic Forest remnants, highlighting the need for sustainable agricultural practices to protect wildlife and ecosystem health.

MAPPING WOOD DENSITY VARIATION USING QGIS: AN INNOVATIVE APPROACH FOR CHARACTERIZATION OF OCHROMA PYRAMIDALE, ACACIA MANGIUM, EUCALYPTUS GRANDIS, AND PINUS SP.

This study explores the innovative application of QGIS for mapping radial wood density variation across the entire cross-section of selected native and non-native forest species, aiming to enhance wood characterization. Using samples from Ochroma pyramidale, Acacia mangium, Eucalyptus grandis, and Pinus sp., we applied X-ray densitometry to obtain high-resolution images, which were then analyzed with QGIS to create detailed density maps. These maps provided a clear visualization of radial density variation, offering insights into the internal structure of the wood. The integration of QGIS with X-ray densitometry proved to be an effective tool for assessing wood density variation, supporting more precise and sustainable forest management practices.

Understory vegetation diversity and composition in intensively managed plantations compared to extensively managed forests

The benefits of plantations for wood production are well known, but it is unclear whether they have a clear negative effect on biodiversity, compared to natural forests. It is also unclear how overstory species identity (i.e., exotic, compared to native) would interact with the simple plantation effects on understory vegetation biodiversity. Here, we assessed bryophyte, lichen, and vascular plant diversity and composition in mono-specific and mixed plantations of exotic and native hybrid poplars (Populus spp.) and exotic and native spruces (Picea spp.). We compared these plantations to reference forests with similar overstory types (coniferous, deciduous, mixed) to those of the plantations in the southern boreal forest of Quebec. We also assessed whether the overstory species identity in plantations influenced understory vegetation biodiversity compared to reference forests. Our results show that plantations were not biological deserts, since mixed plantations contained similar bryophyte and vascular plant diversity as reference mixed native forests. The presence of native spruces and exotic poplars in mixed plantations increased bryophyte and vascular plant diversity respectively. This suggests that the influence of plantations on understory species diversity, compared to reference forests, was linked to the overstory species identity. Plantations were associated with ruderal plant species, while reference forests were composed of forest species. Bryophyte composition was similar in plantations and reference forests, while lichen species were only present in plantations. Our findings highlight that plantations, especially mixtures of white spruce and exotic poplar, are a promising option for planting strategies to enhance biodiversity.