The application of colorimetric parameters for wood quality control, species discrimination, and property evaluation has been described, but no studies have been published comparing the results obtained by colorimetry and spectrophotometry for the analysis of wood. The objective of this study was to establish spectral parameters for 13 native species from an Araucaria forest stand in Southern Brazil using colorimetric and spectrophotometric methods, and to compare the two methods for species discrimination. For each species, three individuals were collected, from which a disc was removed at breast height and divided into six specimens from pith to bark for analysis. Four parameters were determined for each specimen, two on the transversal surface and two on the radial surface, by each method. The results revealed a variation in the parameters L*, a*, and b*, and PCA results varied with the surface and species evaluated. Measurements of the radial surface, in general, yielded a lower species differentiation using the two methods. When considering the potential use of a technique for species identification in the field, it is necessary to rely on prior data obtained using the same method. In conclusion, colorimetry proved to rapidly discriminate native species in Araucaria forest areas.

Revegetation in landslide-affected areas is challenging due to the extensive terrain and poor soil quality. Applying bacteria with plant growth-promoting (PGP) traits offers a promising approach to support plant growth in these disturbed regions. This study aimed to investigate seed enhancement methods by selecting bacterial strains and developing seed pellet mixtures to facilitate revegetation processes. Specifically, we focused on enhancing the germination rate and growth of Acacia confusa through seed pretreatment and inoculation with native bacteria in the growing substrate for pot cultivation and seed pellets. Fifty-four native bacterial strains were isolated from the rhizosphere and endo-rhizosphere of A. confusa growing in the Dadu plateau, Taiwan. Isolates were tested for their ability to stimulate or inhibit the growth of A. confusa seeds on Petri dishes. Sixteen isolates with germination parameters significantly differing from the control were selected for pot tests. 16S rDNA gene sequencing showed that most strains belonged to the genus Bacillus and exhibited one or more PGP traits. Seedling growth parameters were significantly improved by inoculating the substrate with isolates A2TP3 (Bacillus proteolyticus) and A2SP5 (Lysinibacillus sphaericus), which exhibited strong abilities to enhance shoot growth and were therefore selected for evaluation in seed pellet production. Seed germination after inoculation in seed pellets varied with the mixture used. This study demonstrated that bacterial inoculation is a promising bio-inoculant for A. confusa on specific substrates; however, further experiments on seed pelleting mixtures are still needed.

The increasing demand for forest restoration necessitates new strategies and assessments of nutrient returns to support functional restoration. This study aims to evaluate the production, nutrient cycling, and litter decomposition in different restoration models using both different seedling densities and varying proportions of pioneer and non-pioneer species. The experiment was established in 2012, with litter collection occurring in the sixth and seventh years; the leaf fraction was used for chemical analysis. To assess decomposition, litterbags were installed and collected monthly for six months, and climatic data were recorded during this period. The annual litter production in the sixth and seventh years was 7255 and 7953 kg ha-1, respectively. The decomposition process was unaffected by the treatments but was influenced by the microclimate, with minimum temperature showing the strongest correlation. Litter input and nutrient release (kg ha-1) varied significantly only with plant spacing, with the highest releases observed at 1 × 0.3 m spacing. The P, K, and S contents were not affected by either successional groups or plant spacing, while only calcium content varied significantly with the proportion of successional groups. Plant density was linked to higher litter and nutrient production in the system. The highest plant density was more effective at promoting short-term nutrient cycling at the beginning of the restoration process.

Bird habitat use can be influenced by the structural complexity of exotic plantations. Management practices such as pruning and thinning can promote understory development, increasing structural complexity and enhancing ecosystem integrity. Given the rapid expansion of fast-growing tree species, understanding bird responses to different forestry practices is crucial for sustainable management. In northeastern Argentina, we assessed bird habitat use, including trophic guild composition, behavioral patterns, and strata use across native forests and exotic Pinus and Eucalyptus plantations managed to promote or limit understory development. Using non-metric multidimensional scaling (NMDS), hierarchical cluster analysis, and PERMANOVA, we evaluated differences in bird assemblages among these forest types. Our results indicate that plantations with developed understory exhibit habitat use patterns more similar to native forests; however, certain ecologically important species, such as large fruit dispersers, were absent. Among plantation types, Pinus plantations with understory development were the most comparable to native forests in strata use and behavior categories. Birds in both native forests and plantations with developed understory used all available strata and were abundant in the shrub layer, including insectivorous and insectivorous-frugivorous species, whereas plantations lacking understory were functionally similar, exhibiting reduced diversity in trophic guilds. Although Eucalyptus plantations showed greater functional differences from native forests than Pinus plantations, the variation within Eucalyptus plantations based on management practices was particularly striking. We found that although plantations with developed understory cannot fully replicate the ecological functions of native forests, they can mitigate habitat simplification impacts by supporting similar but less abundant trophic guilds with comparable strata use and behaviors. As the demand for exotic plantations increases, effective management practices will become essential for maintaining biodiversity and promoting sustainable land use. Practices such as regular thinning and the establishment of mixed-species plantations can help better replicate the functional roles of native forests, thereby maintaining biodiversity and promoting sustainable land use.

Tropical rainforests experience seasonal variations in water availability, with dry periods resulting in severe soil water scarcity that critically affects seedling performance. A functional trait-based approach, focusing on morphological characteristics, provides a practical means of identifying drought-tolerant tropical woody species for restoration initiatives. This study aimed to evaluate the effects of drought stress on the early establishment of seven tropical woody seedling species and to identify the traits that contribute to seedling performance under these conditions. A greenhouse experiment was conducted to assess seedling responses to varying drought levels, measuring seedling performance (survival rate, relative growth rate, and wilting state) along with traits related to resource acquisition and allocation. The 12-week experiment revealed that drought significantly reduced soil moisture and seedling performance, with species-specific responses. Principal component analysis reveals a shift in trait importance under drought, suggesting altered resource allocation strategies. The root-to-shoot ratio and leaf mass per area emerged as critical indicators of seedling survival during drought, with larger seed and higher leaf dry matter content initially promoting growth but diminishing in effectiveness under severe drought conditions. Larger seeds exhibited greater drought tolerance, as evidenced by lower wilting rates. Although a functional trait-based approach offers valuable information, our results indicate that it may not be fully predictive of seedling performance under all drought scenarios. These findings underscore the importance of selecting species based on their sensitivity to drought stress for specific restoration strategies.

Selection programs on Populus species are primarily aimed at developing fast-growing genotypes. This study aimed to examine the anatomical features of stem xylem and vessel traits in Populus clones, providing valuable parameters to guide future selection and breeding efforts. To achieve this objective, cross-sections of one-year-old shoots of two-year-old trees were analyzed using light microscopy. Measurements of xylem parameters were performed using automated image analysis, and theoretical hydraulic conductance (Kh), vulnerability index (Vi), and vessel grouping index were calculated. Based on our findings, we propose that stem anatomical characteristics related to xylem and vessel traits can serve as valuable tools for selecting poplar clones with enhanced productivity, water-transport efficiency, drought resistance, or cavitation resistance. A significant correlation was found between shoot anatomical properties and Kh and Vi. From an anatomical perspective, breeding efforts aimed at increased growth should prioritize developing clones with a higher xylem proportion (xylem/phloem ratio), larger-lumen vessels, a greater proportion of solitary vessels, and a lower percentage of grouped vessels. Conversely, breeding for drought-tolerant clones and those with enhanced resistance to cavitation should prioritize clones with more small-lumen vessels, a higher percentage of grouped vessels, more vessel groups, and vessel groups with more vessels. The anatomical approach described here is an efficient and accessible method for assessing the growth potential, cavitation tolerance, and drought resistance of poplar trees.

Assessing how bird richness across ecological guilds of mountain-breeding birds responds to changes in forest attributes may inform the development of sustainable management strategies. In this study, we surveyed forest structure and bird communities across 148 sampling units in France and Italy to identify threshold values for stand variables that influence bird species richness. The sampling covered an altitudinal range from 805 to 1555 m a.s.l. and was mainly dominated by mountain beech and Alpine coniferous forests. We modelled species richness of overall bird communities and individual ecological guilds in response to structural and compositional attributes and topographic variables using generalized modelling. Bird species richness was negatively associated with stand-level total tree density. However, higher silver fir density was associated with greater species richness across most bird guilds, which preferred mixed woods and heterogeneous stand structure. An increase in deadwood volume had a significant positive effect on all guilds, confirming the importance of old-growth forest features for forest birds. Threshold values indicating a shift in species richness of bird guilds were identified only for some stand structural attributes (i.e., total basal area and deadwood volume). Our results suggest that the conservation of biodiversity in forest bird communities may benefit from management strategies that maintain mixed, relatively open canopies and promote deadwood retention to ensure the availability of associated habitats. Our approach lays the groundwork for further research, applying this methodology to additional variables and biodiversity metrics.

Forests dominated by black alder (Alnus glutinosa) potentially support habitats with high biological diversity, including rare and endangered species with specific demands for the habitat. However, the knowledge on the response of set-aside black alder forests to adjacent stand management is still insufficient for planning sustainable forest management and requires additional studies on the dynamics of complex organism groups. We conducted repeated inventories of ground vegetation, epiphytic lichens, polypores, and mollusks in the periphery and interior of 10 set-aside black alder-dominated forest stands in Latvia over seven years after adjacent forest management, to determine the response of these organism groups. Our results showed that the diversity of the studied organism groups either remained unchanged or increased from 2004 to 2011. The volume of dead wood increased significantly in all studied plots and correlated positively with polypore abundance and species diversity. We observed an increase in mollusk species number in the stand interior, but not in the periphery plots. No significant spatial differences in forest stand parameters or species diversity were found between stand interior and periphery plots in either the first or the second survey. The obtained results suggested that the 60-meter periphery zone was able to maintain species richness and diversity similar to the interior, highlighting the importance of black alder-dominated forests in supporting species diversity across the studied organism groups.

The potential of Sclerocarya birrea subspecies as native trees to improve agricultural productivity and combat global warming through carbon storage has not been fully explored, despite their extensive distribution across global drylands. The objective of this study was to determine the potential of litterfall from Sclerocarya birrea subspecies to improve soil organic carbon (OC) and fertility, and carbon storage in drylands. Leaf and fruit litterfall samples, comprising 18 samples for each subspecies, from nine trees of subspecies birrea, caffra, and multifoliata were collected in Tanzania. Soil samples were collected under and away from the canopies of the selected trees. The soil pH and the concentrations of organic carbon (OC) and nutrients (total Nitrogen - TN, P, K, Ca, Mg, Na, Cu, Zn, Fe, Mn, S) in the soil, fruit, and leaf litterfall were determined using standard laboratory methods of analysis. The results showed that leaf OC in S. birrea subspecies ranged from 41.16% to 43.49%, and TN from 1.01% to 1.19%. The C:N ratio ranged from 34.58% to 41.66% in leaf, and from 52.73% to 75.12% in fruit litterfall. Phosphorus was significantly higher in fruit (0.17-0.20%) than in leaf (0.02-0.04%) for all subspecies. Ca and Mg were higher in leaf litterfall (0.54-0.89% Ca and 0.19-0.27% Mg), than in fruit litterfall (0.08-0.11% Ca and 0.10% Mg). Cu, Fe, and Mn concentrations were significantly higher in fruit, ranging from 11.71 to 31.42 mg kg-1, 214.13 to 400.59 mg kg-1, and 31.42 to 54.77 mg kg-1, respectively, than in leaf with 3.32 to 4.39 mg kg-1, 64.10 to 107.70 mg kg-1, and 16.08 to 18.97 mg kg-1, respectively. Contrastingly, Zn in leaf ranged from 412.97 in multifoliata to 499.78 mg kg-1 in caffra, which was 33 to 46 times higher than in fruit litterfall. Soils under the canopies of subsp. birrea, caffra, and multifoliata had significantly higher OC and K, Na, and S (p < 0.05), and numerically higher concentrations of most nutrients than soils away from the canopies. We concluded that leaf and fruit litterfall of the Sclerocarya birrea subspecies can improve soil fertility and carbon storage in drylands if managed properly.

Forest structural complexity arises from several attributes whose combined effects make it difficult to disentangle their single contributions. Such contributions may vary substantially across different ecosystems and management types, requiring the development of fast and effective forest structural evaluation indices for simplified, highly managed systems, such as poplar plantations in riparian areas. With this aim, the suitability of the Index of Biodiversity Potential (IBP) to catch the stand structural variations was tested in three different types of poplar forests (cultivated, semi-natural and natural) along the Po river (Northen Italy) in contrast with quantitative structural parameters (e.g., deadwood biomass, diameter diversity) and synthetic structural complexity indices (Index of Structural Heterogeneity - SHI, Forest Structure Index - FSI). The IBP consistently assessed stand structure complexity using structural parameters and synthetic indices. The Gini coefficient for diameter was generally low among sites, but the IBP identified slight variations in vertical structure enabling differentiation between cultivated and non-cultivated stands. The SHI showed the strongest correlation with IBP, likely due to its context-related features and its ability to describe structural differences within a relatively homogeneous forest stand. Although data on the presence of large woody elements in IBP allow distinctions among stand types, the lack of their quantification may lead to an overestimation of their actual role in forest biogeochemical cycles. In conclusion, the IBP, with some site-specific refinements, could represent a suitable and rapid method for implementing management plans to enhance woodland stand complexity in riparian areas.