Forest Function Research Articles

Interactions between leaf traits and environmental factors help explain the growth of evergreen and deciduous species in a subtropical forest

It is well known that evergreen and deciduous species possess different functional traits and utilize different strategies in growth and adaptation to environments. However, little work has been done to elucidate whether leaf habits mediate the effect of trait-environment interactions on plant performance. In this study, our subjective was to illuminate whether relative growth rate of deciduous and evergreen species is influenced by multiple trait-environment interactions. We conducted measurements on eight leaf traits of 1230 individuals belonging to 25 species in a subtropical evergreen and deciduous broad-leaved mixed forest. Additionally, we collected data on topographic factors, edaphic variables and competition index. Subsequently, we employed generalized linear mixed model to analyze plant relative growth rate, considering high-order trait-environment interactions for both evergreen and deciduous species. We also visualized the effects of these interactions on growth patterns. Our results showed that leaf habits were divided by trait PC1 (41.8%) which was related to leaf lifespan and resource acquisition. Evergreen species tended to have greater interspecific variation compared to deciduous species. Notably, the inclusion of trait-environment interactions significantly improved growth predictions for both leaf habits, although explanatory power of deciduous models was always higher than that of evergreen species. Furthermore, we observed variability in the effects of trait-environment interactions on plant performance varied between leaf habits, leading to different optimal models for each leaf habit, even when they shared similar trait-environment context. These results indicated that difference of life history strategies between leaf habits could be reflected by trait-environment interactions. We emphasized the importance of leaf habits in explaining forest productivity and functions, and future research should focus on the effects of leaf habits on other demographic metrics to understand species coexistence in mixed forests.

Species and structural diversity of trees at the structural type level

BackgroundSpecies and structural diversity are important for understanding the formation of forest communities, key ecological processes, and improving forest ecological functions and services, but their spatial characteristics have received little attention. Based on the spatial relationships among neighbouring trees, we proposed to divide trees within a structural unit into 15 structural types, and used the univariate distributions of the uniform angle index (W), mingling (M), and dominance (U), along with four common species diversity indices, to analyse the diversity of structural types in natural forests near the Tropic of Cancer.ResultsOnly a portion of clumped class maintained aggregation, most exhibited a random pattern. Species mixture increased exponentially across distribution classes, and abundance and richness exhibited an initial increase followed by a slight decrease. The distribution patterns of mixture classes varied from highly clustered to random, and M distributions gradually shifted from an inverted J-shaped curve to a J-shaped curve. Abundance and richness exhibited an exponential distribution, whereas the Shannon–Wiener index increased linearly. The W distribution of differentiation classes approximated a normal distribution, whereas M distributions exhibited a J shape. The U distribution of each structure type was approximately 0.2.ConclusionsThese results reveal the species and structural diversity characteristics of trees at the structural type level and expand our knowledge of forest biodiversity. The new method proposed here should significantly contribute to biodiversity monitoring efforts in terrestrial ecosystems, and suggests that higher standards for the simulation and reconstruction of stand structure, as well as thinning in near-natural forests, is warranted.

The Impact of Natural Disturbances on the Central European Timber Market—An Analytical Study

Central European countries are strategic wood exporters in the European and international wood trade. In the context of wood exporters, Czechia, Germany, Poland, Slovenia, and Austria are the important countries providing the development and stability of the forestry and wood sector. The share of these countries’ exports in total EU exports represents more than 52% of the volume of wood exported over 5 years. After the Netherlands, the five mentioned countries recorded the highest increase in roundwood production of all EU and EFTA countries in the years 2000–2022 (from 46% (AT)–126% (CZ)), and the European average is 26%. The last decade has been characterised by a significant destabilisation of the Central European timber market as a result of natural disturbances linked to climate change, which also threatens the long-term competitiveness and preservation of this sector in the economic systems of national economies. The article provides an analytical insight into the historical development of natural calamities and their macroeconomic consequences in Central European countries. The data forecast an unfavourable development of the timber market in Europe caused by the ongoing calamity situation, the pricing policy of the timber trade, the oversaturation of the market with lower-quality calamity timber, insufficient processing capacities for primary processing of wood and its use in secondary processing, and, last but not least, the limited stock of timber in the coming years in selected Central European countries (due to an extreme increase in harvesting plans within the last 5 years, with consequences that will be felt in the coming decade). For the continued economic function of forests and the availability of wood supply for future generations, the current evolution of calamities in forest ecosystems is critical, and long-term strategic measures based on empirical data are necessary. The information presented in this paper can serve as a tool for the objectification of strategic decisions in the development of forestry policies in selected countries.

Assessing the Performance of Handheld Laser Scanning for Individual Tree Mapping in an Urban Area

Precise individual tree or sample-based inventories derived from 3D point cloud data of mobile laser scanning can improve our comprehensive understanding of the structure, function, resilience, biodiversity, and ecosystem services of urban forests. This study assessed the performance of a handheld laser scanning system (HLS) for the extraction of tree position, diameter at breast height (DBH), and tree height (H) in an urban area. A total of 2083 trees of 13 species from 34 plots were analyzed. The results showed that the registration of tree positions using ground control points (GCPs) demonstrated high accuracy, with errors consistently below 0.4 m, except for a few instances. The extraction accuracy of DBH for all trees and individual species remained consistently high, with a total root mean square error (RMSE) of 2.06 cm (6.89%) and a bias of 0.62 cm (2.07%). Notably, broad-leaved trees outperformed coniferous trees, with RMSE and bias values of 1.86 cm (6%) and 0.76 cm (2.46%), respectively, compared to 2.54 cm (9.46%) and 0.23 cm (0.84%), respectively. The accuracy of H extraction varied significantly among different species, with R2 values ranging from 0.65 to 0.92. Generally, both DBH and H were underestimated compared to ground measurements. Linear mixed-effects models (LMEs) were applied to evaluate factors affecting the performance of HLS with the plot as a random factor. LME analysis revealed that plant type and terrain significantly influenced the accuracy of DBH and H derived from HLS data, while other fixed factors such as plot area, tree density, and trajectory length showed no significance. With a large sample size, we concluded that the HLS demonstrated sufficient accuracy in extracting individual tree parameters in urban forests.

Land degradation and development in India: Status quo, challenges and opportunities

AbstractThis article reviews and synthesizes the articles published in a virtual special issue (VSI) “Land Degradation and Development in India: Status quo, challenges, and opportunities.” A total of 31 studies (28 research papers and three reviews) are published in this VSI covering various agroclimatic zones of India. These articles provide insights on how different natural and anthropogenic disturbances affect the diversity, and functioning of forests, grasslands, agriculture, agroforestry, and physicochemical and biological composition of the soil. Twelve of these articles also investigate the effectiveness of different restoration methods to restore various degraded ecosystems through agroforestry, afforestation and reforestation, organic amendments, and agroecological interventions. The historical journey of forest restoration, behavioral pattern of local communities for conservation and restoration, and policy framework for restoration in India are discussed in three independent articles. Overall, there is convergence in learnings from these papers for structural and non‐structural land degradation, soil salinization, and agroforestry but results from papers on plantations and organic inputs into farming highlight the need for more research.

Hydrological effects of the conversion of tropical montane forest to agricultural land in the central Andes of Peru

AbstractAgricultural expansion is one of the main causes of deforestation of tropical montane forests in the central Andes of Peru. The hydrological impacts of converting forests to cropland are well known; however, an issue that is not entirely clear is related to the hydrological effects that can result from the conversion of montane forests to agroforestry systems and the recovery of the hydrological functions of montane forests after a disturbance. In this study, we compare the hydrological processes of different land covers previously modified by agricultural expansion, in order to determine the impact of the conversion of tropical montane forest to agricultural land on the ecosystem service of water provision and regulation. To achieve this, we establish study plots in four land cover types located in the central Andes of Peru (mature montane forest (BMC), natural regenerating secondary forest (BMR), coffee agroforestry systems (AF), and cropland (C)), for the purpose of measuring the vegetation structure and soil properties in them, and subsequently carry out a soil water balance in each plot to calculate the actual evapotranspiration, surface runoff, and groundwater recharge. The results revealed the following percentages (based on precipitation) for the hydrological components in the four land cover types: annual actual evapotranspiration—BMR (41.2%), AF (40.4%), BMC (40.0%), and C (38.0%); annual surface runoff—C (16.1%), BMC (8.3%), BMR (5.2%), and AF (4.6%); and annual groundwater recharge—AF (43.0%), BMR (41.6%), C (34.0%), and BMC (31.7%). Furthermore, the study also examined the relationship between vegetation structure and the hydrological components across the four land cover types. The findings indicated that the reduction of thicker and taller trees could increase surface runoff generation, whereas the presence of thinner and shorter trees could facilitate groundwater recharge. These results shed light on the complex interactions between land cover types, vegetation structure, and hydrological processes, emphasizing the importance of considering these factors in water resource management and land use planning.

Dominant herbaceous plants contribute to the spatial heterogeneity of beech and riparian forest soils by influencing fungal and bacterial diversity

Understanding of factors that shape diversity patterns in forest ecosystems is a main challenge in forest ecology and management practices. Although herbaceous plants are known to contribute to the maintenance of the structure and function of temperate forests, their impact on fungal and bacterial communities in soils is largely unknown. Therefore, we conducted a comparative study of soil fungal and bacterial diversity in two Central European deciduous forests, focusing on plots with dominant herbaceous species of contrasting morphology, phenology, reproduction, and ecology, including Allium ursinum and Dentaria enneaphyllos in a beech forest, as well as Aegopodium podagraria and Ficaria verna in a riparian forest. Plots with a mixture of herbaceous species and without plant cover were also studied. In both forests, fungal communities showed the strongest association with spatial location, part of which was explained by between-site variability in soil chemistry and was also influenced by herbaceous vegetation. The community composition of saprotrophic fungi depended on the presence and type of herbaceous vegetation in both forests. In addition, herbaceous plants affected the composition of arbuscular mycorrhizal fungi community in the beech forest, while in the riparian forest they affected endophytes and plant pathogens. For bacteria, soil chemistry played the most important role. Our results showed that dominant herbaceous vegetation is one of the drivers shaping microbial community composition, contributing to spatial heterogeneity of forest sites. Given that herbaceous species, especially those forming monospecific patches, affect the soil biotic properties in temperate forests, they should be included in forest management practices.

Spatiotemporal variation in the negative effect of neighbourhood crowding on stem growth

Abstract Neighbourhood interactions drive tree growth and forest ecosystem functioning. The strength of interactions depends on the climate. However, it remains unclear how plant–plant interactions are modified by environmental conditions operating both spatially and temporally, which is crucial for predicting forest dynamics under climate change and for effective forest management. In this study, we used annual growth data for 4139 stems from 2010 to 2021 across 50 permanent forest plots located at six sites in eastern China. We quantified the effect of neighbourhood crowding on the annual basal area increment. We explored how interactions among neighbouring trees vary with water availability and temperature gradients in the spatial (across sites) and temporal (across time within sites) dimensions. Our findings revealed a negative impact of neighbourhood crowding on stem basal area growth, which is size‐ and trait‐dependent at some sites. The negative effects of light competition tended to be more intense at warmer sites, supporting the stress‐gradient hypothesis (SGH) in a spatial dimension. However, the patterns of crowding effects along interannual climate anomalies are inconsistent across sites, making it difficult to predict crowding effects under the SGH framework in a temporal dimension. Synthesis: Our study demonstrated that tree interactions depend on the climate context. The climate dependence of interactions may be inconsistent between the spatial and temporal dimensions. Light competition across sites supported the SGH in the spatial dimension but not in the temporal dimension. These results further highlight the complexity of biotic interactions and the need for caution when extrapolating findings from the spatial to the temporal dimension.

Methods for economic assessment of forest resource degradation: A systematic review

Forest degradation is one of the challenges facing the planet today. Several methods have been used to measure forest degradation, including spatiotemporal model analysis, satellite analysis, remote sensing, time series data, geospatial techniques, and most recently aerial drone imagery. However, few studies have used economic valuation methods to assess forest degradation. Therefore, this research aimed to identify the methods used the economic assessment of forest degradation. This systematic review was carried out using PRISMA guidelines. Research articles on the economic valuation of forest resource loss, published from 2015 to 2022, were electronically collected from three databases. Three independent reviewers, with the third acting as referee, inventoried articles, extracted data, and assessed the risk of bias in the articles included in the study. A total of 10,095 articles were identified, including one article from the grey literature. Only five articles met the eligibility criteria. A qualitative content analysis was performed on the extracted data. The selected articles used various methods. However, only a few articles used the contingent valuation method, even though this is indicated for estimating the highest economic value of forests. Based on forest functions, the articles evaluated erosion due to the absence of trees, wood loss, recreation areas and externalities due to forest loss, air quality, water regulation, food supply, and wildlife. The main limitation of this review was the small number of studies included, which may have affected the findings. The study protocol is registered in PROSPERO under the number CRD42021223242

Post-harvest regeneration is driven by ecological factors rather than wood procurement intensity in eastern Canadian forests

Abstract Biomass from surplus forest growth that is not harvested for wood supply of conventional industries can be an important source of feedstock for bioenergy. Its procurement can be integrated with little effort into current harvest operations. However, the increasing harvesting intensity to meet greater demand for biomass procurement can impact forest ecosystem functions because of its direct and indirect effects on woody debris and the regeneration of next-rotation stands. In this context, we aimed to determine the relationships between wood procurement intensity, woody debris inputs, and regeneration success over 2 years after harvesting. We tested four treatments of increasing wood procurement intensity using a randomized block design within six experimental sites along a gradient of varying forest characteristics of boreal and temperate forests. We assessed stand characteristics in terms of standing trees, woody debris, and regeneration pre- and post-harvest. We used mixed effects models to evaluate (i) the effects of wood procurement intensity and pre-harvest stand characteristics on the volume and cover of woody debris and (ii) the specific influence of woody debris on the presence of suitable planting microsites post-harvest. Furthermore, we used principal component regressions to explore the relationships between harvesting intensity and the presence of natural regeneration and competing vegetation as a function of pre- and post-harvest stand characteristics (iii). Our results showed that increasing wood procurement intensity reduced the volume of post-harvest woody debris while having a limited effect on regeneration. Increasing harvesting intensity had a negligible effect on suitable planting microsites in hardwood-dominated stands but it increased their presence in conifer-dominated stands. Natural regeneration and competing vegetation were mainly related to stand characteristics, and only broadleaf regeneration was sensitive to harvest intensity. We conclude that the relationships between wood procurement intensity and regeneration are complex and rely mainly on stand characteristics rather than wood procurement needs.

Stability Analysis of a Delayed Paranthrene tabaniformis (Rott.) Control Model for Poplar Forests in China

Forest pests and diseases can diminish forest biodiversity, damage forest ecosystem functions, and have an impact on water conservation. Therefore, it is necessary to analyze the interaction mechanism between plants and pests. In this paper, the prevention and control of a specific pest—namely the larva of Paranthrene tabaniformis (Rott.) (hereinafter referred to as larva)—are studied. Based on the invasion mechanism of the larva in poplar, we establish a delayed differential equation and analyze the existence and stability of equilibria. Next, we assess the existence of a Hopf bifurcation to determine the range of parameters that ensures that the equilibria are stable. Then, we select a set of parameters to verify the results of the stability analysis. Finally, we provide biological explanations and effective theoretical control methods for poplar pests and diseases.

How Organic Mulching Influences the Soil Bacterial Community Structure and Function in Urban Forests.

Urban forest soil is often disturbed by frequent human activity. Organic mulching is effective for improving soil quality; however, the effects of organic mulching on soil bacterial communities in urban forests are still largely unexplored. This study evaluated how organic mulching changed the urban forest soil bacterial community through an incubation experiment. Four treatments were applied: (1) no organic mulch (CK); (2) wood chips alone (5 g, Mw); (3) wood compost alone (5 g, Mc); and (4) wood chips + wood compost (This mulch was divided into two layers, i.e., the upper layer of wood chips (2.5 g) and the lower layer wood compost (2.5 g, Mw+c).) We found significant differences in the soil physicochemical properties under organic mulching after incubation. Overall, organic mulching can alter soil bacterial community structure. Soil alkali-hydrolyzable nitrogen, soil organic carbon, soil total nitrogen, and carbon-nitrogen ratio were the main factors affecting soil microbial community structures. Soil bacterial groups under organic mulching treatments mainly acted on the C and N cycling of functional pathways in soil. This study suggests that organic mulching could maintain the development of soil bacteria, which establishes a theoretical foundation for enhancing the microbiological environment of urban forest soils.

Response of tree growth to nutrient addition is size dependent in a subtropical forest

Understanding how nutrient addition affects the tree growth is critical for assessing forest ecosystem function and processes, especially in the context of increased nitrogen (N) and phosphorus (P) deposition. Subtropical forests are often considered N-rich and P-poor ecosystems, but few existing studies follow the traditional “P limitation” paradigm, possibly due to differences in nutrient requirements among trees of different size classes. We conducted a three-year fertilization experiment with four treatments (Control, N-treatment, P-treatment, and NP-treatment). We measured soil nutrient availability, leaf stoichiometry, and relative growth rate (RGR) of trees across three size classes (small, medium and large) in 64 plots. We found that N and NP-treatments increased the RGR of large trees. P-treatment increased the RGR of small trees. RGR was mainly affected by N addition, the total effect of P addition was only 10 % of that of N addition. The effect of nutrient addition on RGR was mainly regulated by leaf stoichiometry. This study reveals that nutrient limitation is size dependent, indicating that continuous unbalanced N and P deposition will inhibit the growth of small trees and increase the instability of subtropical forest stand structure, but may improve the carbon sink function of large trees.

Geospatial approaches for formulating multisystem silviculture in the tropical forests

The Indonesian Ministry of Environment and Forestry (MoEF) issued regulations that allow the use of multiple silvicultural systems throughout a single period of a forest management work plan, known as multisystem silviculture (MSS), to increase the productivity and economic value of forests. However, certain technical issues still need to be resolved before an MSS can be successfully implemented on-site, particularly in terms of scheming the silvicultural system and selecting the appropriate site. This study developed silvicultural systems based on the modelling of geospatial data on current land cover, forest function, slope, and erosion risk. In this study, forest harvesting techniques (prohibited, selective, and clear-cutting) and regeneration approaches (natural, enrichment, and line planting) were formulated by overlaying four thematic maps and applying modelling rules. For specific locations, overlay thematic modelling maps of forest harvesting and regeneration techniques have been verbalized as MSS, such as selective cutting with enrichment planting, selective cutting with line planting, clear-cutting with intensive planting, and many other systems. The results of this geospatial modelling will assist forest managers in creating forest management plans with MSS within particular forest objectives. Additionally, this study supports policymakers in rising technical procedures for implementing multisystem silviculture.

Trophic interactions in soil micro-food webs drive ecosystem multifunctionality along tree species richness.

Rapid biodiversity losses under global climate change threaten forest ecosystem functions. However, our understanding of the patterns and drivers of multiple ecosystem functions across biodiversity gradients remains equivocal. To address this important knowledge gap, we measured simultaneous responses of multiple ecosystem functions (nutrient cycling, soil carbon stocks, organic matter decomposition, plant productivity) to a tree species richness gradient of 1, 4, 8, 16, and 32 species in a young subtropical forest. We found that tree species richness had negligible effects on nutrient cycling, organic matter decomposition, and plant productivity, but soil carbon stocks and ecosystem multifunctionality significantly increased with tree species richness. Linear mixed-effect models showed that soil organisms, particularly arbuscular mycorrhizal fungi (AMF) and soil nematodes, elicited the greatest relative effects on ecosystem multifunctionality. Structural equation models revealed indirect effects of tree species richness on ecosystem multifunctionality mediated by trophic interactions in soil micro-food webs. Specifically, we found a significant negative effect of gram-positive bacteria on soil nematode abundance (a top-down effect), and a significant positive effect of AMF biomass on soil nematode abundance (a bottom-up effect). Overall, our study emphasizes the significance of a multitrophic perspective in elucidating biodiversity-multifunctionality relationships and highlights the conservation of functioning soil micro-food webs to maintain multiple ecosystem functions.

Sensitivity of long-term productivity estimations in mixed forests to uncertain parameters related to fine roots

Forest growth models are increasingly being used in forestry and ecology research as predictive tools to help developing practical guidelines and to improve understanding of the drivers of forest ecosystem functioning. Models are usually calibrated using parameters directly obtained or estimated from empirical field observation, and hence are subject to uncertainty. Thus, output accuracy depends on input parameters precision and on how influential is each parameter on model behaviour. Hence, it is important to analyse parameter-related uncertainty and its effects on model outputs. This can be done by performing sensitivity analyses, which allow to explore the influence of one or several calibration parameters on model outputs. As studies on tree root parameters are particularly scarce, the aim of the present work was to evaluate the influence of parameters related to fine roots on estimations of long-term forest growth patterns in pure and mixed forests, using FORECAST (a hybrid forest growth model) as a virtual lab. The fine root parameters assessed were biomass, turnover rate, and nitrogen content. The analysis was performed by simulating monospecific stands of two contrasting species (Pinus sylvestris L. and Fagus sylvatica L.), and mixed stands formed by both species. In all cases, FORECAST showed good capability to contain uncertainty propagation during the first and middle stages of stand development (<40 years). After that moment, model output uncertainty steadily increased, but it reached different maximum uncertainty levels depending on stand type. Simulations of the less nutrient demanding P. sylvestris manifested very little sensitivity when growing in monospecific stands. However, F. sylvatica monospecific stands showed intermediate sensitivity, but significant species interactions occurred in mixed stands that determined the biggest impact detected of uncertainty related to fine root parameters over model outputs. All things considered, FORECAST displayed an interesting capability to capture some of the interspecific interactions that are key in mixed forests functioning. Our results suggest an acceptable model performance under uncertain parameterization but also caution against expecting accurate quantitative estimations of forest growth, especially when considering long-term scenarios in complex mixed stands.

Toward a coordinated understanding of hydro-biogeochemical root functions in tropical forests for application in vegetation models.

Tropical forest root characteristics and resource acquisition strategies are underrepresented in vegetation and global models, hampering the prediction of forest-climate feedbacks for these carbon-rich ecosystems. Lowland tropical forests often have globally unique combinations of high taxonomic and functional biodiversity, rainfall seasonality, and strongly weathered infertile soils, giving rise to distinct patterns in root traits and functions compared with higher latitude ecosystems. We provide a roadmap for integrating recent advances in our understanding of tropical forest belowground function into vegetation models, focusing on water and nutrient acquisition. We offer comparisons of recent advances in empirical and model understanding of root characteristics that represent important functional processes in tropical forests. We focus on: (1) fine-root strategies for soil resource exploration, (2) coupling and trade-offs in fine-root water vs nutrient acquisition, and (3) aboveground-belowground linkages in plant resource acquisition and use. We suggest avenues for representing these extremely diverse plant communities in computationally manageable and ecologically meaningful groups in models for linked aboveground-belowground hydro-nutrient functions. Tropical forests are undergoing warming, shifting rainfall regimes, and exacerbation of soil nutrient scarcity caused by elevated atmospheric CO2. The accurate model representation of tropical forest functions is crucial for understanding the interactions of this biome with the climate.

Evaluating Dendrolimus superans (Lepidoptera: Lasiocampidae) Occurrence and Density Modeling with Habitat Conditions

Dendrolimus superans, a prominent forest pest in northeast China, exerts detrimental effects on tree growth and development, disrupts the ecological functioning of forests, and even alters the trajectory of succession. The objective of this study was to investigate the influence of habitat conditions on the occurrence probability and density of overwintering D. superans, aiming to provide scientific insights for the effective prevention of and control measures against this pest infestation. The investigation encompassed 142 plots (20 m × 20 m) in various forest types within the primary distribution area of D. superans in the Great Xing’ an Mountains, focusing on factors such as topography, forest vegetation, and larval density. Binary logistic regression was employed to establish models for predicting the occurrence probability of D. superans, while generalized linear models (GLMs) and categorical regression (CATREG) were utilized to develop models for estimating its population size. Subsequently, an evaluation was conducted to assess the performance of these models. The occurrence probability model showed high accuracy (AUC = 0.826) in predicting infestation. The slope aspect and herb cover were the key factors affecting the occurrence of D. superans. The occurrence probability was the lowest on shady slopes and the highest on sunny slopes. The occurrence probability of D. superans increased with the increase in herb cover. The model of quantification showed that the density of D. superans was the least on shady slopes and the highest on sunny slopes. As the slope gradient increased, the density decreased. D. superans occurred most frequently on ridges. Similarly, with the increase in canopy cover or the decrease in diameter at breast height (DBH) and stand density, the density of D. superans increased. The influence of the topography factors surpassed that of the forest vegetation factors in shaping the population dynamics of D. superans, despite both being significant contributors. The study revealed that D. superans is prone to occur on sunny slopes, flat slopes, and ridges, which should be the focus of prevention and control in forest management practices, such as replanting, thinning, and regular weeding, to help restrain the growth of the population of this pest.

Local tourists’ perception towards mangrove forest conservation and regeneration in the Guang-guang Mangrove Park and Nursery, Davao Oriental, Philippines

Mangroves are crucial for preserving and safeguarding coastal communities and the ecosystem along the shore. This study focused on determining the perception of local tourists towards the importance and current efforts and initiatives for mangrove forest conservation and regeneration in Guang-Guang, Dahican, City of Mati, Davao Oriental, Philippines. Using in-depth interviews with ten local tourists, major themes relating to and difficulties facing conservation and regeneration programs, as well as the ecosystem services and functions of mangrove forests, were investigated. The local tourists perceived that mangroves operate as storm barriers, prevent coastal erosion, and serve as essential habitats for aquatic organisms. However, anthropogenic activities like the establishment of shrimp ponds, plastic pollution, land reclamation, and illegal logging were documented to threaten the mangrove forests. The study also highlighted the government's efforts to implement regeneration programs and engage local communities and stakeholders in tree planting and coastal clean-up activities. The significance of mangrove forest conservation and regeneration was underscored, considering their roles in providing habitats, protecting coastlines, promoting biodiversity, and supporting livelihoods. The implications of the study emphasized the need to raise public awareness, improve environmental education, involve communities in decision-making, and implement regenerative conservation initiatives.

Diversity patterns along ecological succession in tropical dry forests: a multi‐taxonomic approach

Evaluating the diversity of multiple taxa is fundamental to understand community assembly and to assess the integrity and functionality of tropical secondary forests. In this study, we analyzed the natural regeneration of tropical dry forests (TDFs) in three regions of Brazil using Hill–Simpson diversity, abundance and β‐diversity of trees and five groups of insects (herbivores, fruit‐feeding butterflies, ants, culicid mosquitoes and dung beetles). Sampling was conducted in 39 0.1 ha plots using a chronosequence approach (13 plots in early, intermediate and old‐growth forests). We evaluated the contribution of three different levels to γ‐diversity: α (within plots), β1 (among plots) and β2 (among successional stages), and further determined the relative importance of turnover (species replacement) and nestedness (differences in species number among sites) to β2. Our results showed that, unexpectedly, the Hill–Simpson diversity was consistently higher in early than old‐growth stages for all regions, but varied more widely in the intermediate stages. For each group separately, the same trend was observed for butterflies, ants, dung beetles and herbivores and did not differ among stages for mosquitoes. Successional differences in abundance were only detected for trees (increasing along the gradient) and for mosquitoes (decreasing). According to our expectations, the additive partitioning analysis showed that β2‐diversity contributed more to γ‐diversity than β1‐diversity, when all taxa were considered together and for most of them separately (except for butterflies and dung beetles). Most of the β2‐diversity was due to species turnover, but this contribution varied among groups and regions, with the highest turnover for herbivores and the lowest for dung beetles. Our results suggest that the Hill–Simpson diversity and changes in species composition (as given by β2‐diversity) are better indicators of forest natural regeneration than raw species richness, corroborating previous studies with plants and animals.