Forest Plantations Research Articles

Direct observations of evapotranspiration from three contrasting vegetation types on a coastal low-lying sub-tropical sand island

Coastal low-lying sand islands confront an imminent threat owing to global warming, primarily stemming from the confluence of rising sea levels and amplified precipitation variability. These islands harbour delicate freshwater reservoirs in unconfined aquifers, reliant significantly upon precipitation for replenishment. This investigation focuses on a sand island situated along Australia’s eastern coast, resembling islands prevalent across the Indian and Pacific Oceans. The study involves comprehensive instrumentation to monitor Actual Evapotranspiration (AET) concurrently with rainfall patterns and water table fluctuations. Eddy Covariance (EC) systems were employed across three distinct vegetation zones: a wetland, a swamp, and a commercially managed pine forest plantation. The aim was to gauge evapotranspiration dynamics, comparing computed reference evapotranspiration (ET0) at each site with EC-measured values to establish novel reference vegetation coefficients (Kv) tailored to these specific environments. Actual evapotranspiration was found the largest at the wetland, the swamp, and the pine plantation in decreasing order. Pine plantation evapotranspiration was found the most sensitive to water table depth, while the native swamp and wetland maintained high evapotranspiration rates through dry periods. A simple idealized water balance is proposed for the island for the dry and wet seasons. Large rainfall events during the wet season were found critical in providing recharge of the aquifer, highlighting the importance of such events in maintaining the freshwater resource and vegetation health on such islands.

Current State of Wild Pistacia lentiscus in Azerbaijan

Information is provided on Pistacia lentiscus L. belonging to natural forest vegetation, Anacardiaceae family, Pistacia genus. Information is given on the modern status and importance of Pistacia lentiscus L., which is one of the wild tree species in the flora of Azerbaijan. Due to its resin content, the Pistacia lentiscus is a valuable plant that is resistant to pests and used in various fields. The Pistacia lentiscus is a long-lived tree that coexists with other forest plants.

Effects of Nitrogen Addition on Soil Microbial Biomass: A Meta-Analysis

Most studies about the effects of N addition on soil microbial biomass evaluate soil microbial and physicochemical characteristics using single-test methods, and these studies have not been integrated and analyzed to comprehensively assess the impact of N fertilization on soil microbial biomass. Here, we conduct a meta-analysis to analyze the results of 86 studies characterizing how soil microbial biomass C (MBC), N (MBN), and P (MBP) pools respond to exogenous N addition across multiple land use types. We found that low N addition (5–50 kg/hm2) rates significantly affect soil microbial biomass, mainly by increasing MBC but also by decreasing MBP and significantly increasing MBC/MBP. N addition affects soil physicochemical properties, significantly reducing pH and significantly increasing the soil dissolved organic N and inorganic N content. Our analysis also revealed that the effects of N application vary across ecosystems. N addition significantly decreases MBP and total P in planted forests but does not significantly affect soil microbial biomass in grasslands. In farmland soil, N addition significantly increases total P, NH4+, NO3−, MBN, and MBP but significantly decreases pH. Although N addition can strongly influence soil microbial biomass, its effects are modulated by ecosystem type. The addition of N can negatively affect MBC, MBN, and MBP in natural forest ecosystems, thereby altering global ecosystem balance.

Land use to agriculture and planted forests strongly affect the genetic diversity of Baccharis crispa Spreng., a native herb of South America

Abstract Human population growth constantly requires an increase in the production of food and products from the timber industry. To meet this demand, agriculture and planted forests are advancing over natural areas. In view of this, it is necessary to know the effects of land use for different purposes (grain production, pastures, planted forests, fruit production, among other uses) on the genetic diversity of populations of native species. This knowledge can assist in land use planning as well as in the development of conservation strategies for native species. In this study, we evaluated the effect of land use for agriculture (mainly for cereal production) and planted forests on the genetic diversity of Baccharis crispa Spreng., a herb native to South America. To achieve our goals, we compared population genetic data obtained with three molecular markers (microsatellites, ISSR [inter-simple sequence repeat] and isoenzymes) with data on land use for agriculture and planted forests from 15 different locations. Our results showed that regardless of the molecular marker used, the greater the use of land for agriculture and planted forests, the lower was the genetic diversity of B. crispa populations. Baccharis crispa is a semi-perennial species that needs at least one year to reach its reproductive period, which is prevented in agricultural areas due to the land being turned over or dissected with herbicides every six months. In the studied regions, the planted forests are of eucalypt and/or pine, which besides being species with a high production of allelopathic substances, produce strong shading and B. crispa is a species that inhabits open grassland that needs high incidence of sunlight for development. The data obtained in our study can assist in the decision-making to use land in order to reconcile the production of supplies for humanity and for the conservation of nature.

Genetic resources of African mahogany in Brazil: genomic diversity and structure of forest plantations

BackgroundAfrican mahogany species (Khaya sp.) have been introduced to Brazil gaining increasing economic interest over the last years, as they produce high quality wood for industrial applications. To this date, however, the knowledge available on the genetic basis of African mahogany plantations in Brazil is limited, which has driven this study to examine the extent of genetic diversity and structure of three cultivated species (Khaya grandifoliola, Khaya senegalensis and Khaya ivorensis) and their prospects for forest breeding.ResultsIn total, 115 individuals were genotyped (48 of K. grandifoliola, 34 of K. senegalensis and 33 of K. ivorensis) for 3,330 filtered neutral loci obtained from genotyping-by-sequencing for the three species. The number of SNPs varied from 2,951 in K. ivorensis to 4,754 in K. senegalensis. Multiloci clustering, principal component analysis, Bayesian structure and network analyses showed a clear genetic separation among the three species. Structure analysis also showed internal structure within each species, highlighting genetic subgroups that could be sampled for selecting distinct genotypes for further breeding, although the genetic distances are moderate to low.ConclusionIn our study, SNP markers efficiently assessed the genomic diversity of African mahogany forest plantations in Brazil. Our genetic data clearly separated the three Khaya species. Moreover, pairwise estimates of genetic distances among individuals within each species showed considerable genetic divergence among individuals. By genotyping 115 pre-selected individuals with desirable growth traits, allowed us not only to recommend superior genotypes but also to identify genetically distinct individuals for use in breeding crosses.

Green Initiatives for Climate Change Mitigation in Palakkad District of Kerala, India

Trees and forested ecosystems play a significant role in in meeting global commitments on sustainable development as well as adaptation to climate change and mitigation of its impacts. Aggressive tree planting goals to achieve canopy cover growth targets are a common manifestation to overcome the climate change challenges. Miyawaki forest creation, a method developed by Japanese botanist Akira Miyawaki, involves planting trees per square meter which is intended for intensification of green cover to support local biodiversity. A food forest is essentially a planned and planted forest of food plants that provides a variety of food throughout the year. While both Miyawaki forest and food forest aim to restore ecosystems and enhance biodiversity, they differ in their design, purpose, and management practices. Hence a study on comparative analysis of food forests and Miyawaki forests was envisaged to highlight their respective benefits, challenges, and implementation strategies. The present investigation was undertaken on selected institutions of Palakkad district of Kerala namely Krishi Vigyan Kendra Palakkad where Miyawaki forest patch is created at its premises and V T Bhattathiripad College, Sreekrishnapuram where food forest is established. From this study it is understood that Miyawaki forest is reconnecting with the nature by harboring an array of native flora and fauna promoting biodiversity conservation and habitat restoration while food forest is reconnecting with nature by providing food source for pollinated server, as a habitat for many animals and it is very ecofriendly because don’t require any chemical pesticides. These techniques are highly effective in the establishment of urban forests as well as converting unproductive waste lands into ecological and socially beneficial productive lands.

Enhanced soil microbial stability is associated with soil organic carbon storage under high-altitude forestation

The potential of forestation to mitigate climate warming depends largely on whether it can improve terrestrial carbon (C) storage. Changes in soil microbial stability can cause ecosystem C fluctuations. Unfortunately, it remains unclear whether forestation alters soil microbial stability with cascading effects on C storage in high-altitude ecosystems. In this study, a total of 14 typical planted forests were selected on the Tibetan Plateau. We showed that high-altitude forestation, particularly with poplars, altered the microbial diversity and potentially improved the stability of soil microbial communities. These changes were associated with soil C accumulation and potentially positive feedback on soil organic C storage. Variations in the microbial community stability were mostly caused by changes in soil bulk density and dissolved organic C. Superior network stability was found in fungal community rather than bacterial community. Additionally, there were strong interactions between bacterial and fungal communities that influenced soil C storage. These findings contribute to understand the differences and relationships between bacteria and fungi in plantation soils. This work reveals the potential of high-altitude forestation to mitigate climate warming through insights into the microbial-mediated mechanisms responsible for soil C storage in high-altitude ecosystems.

The importance of different forest management systems for people’s dietary quality in Tanzania

ContextA large body of literature has shown that forests provide nutritious foods in many low- and middle-income countries. Yet, there is limited evidence on the contributions from different types of forest and tree systems.ObjectivesHere, we focus on individual trees and smaller forest patches outside established forest reserves as well as different forest management systems.MethodsWe do so by combining novel high-resolution data on tree cover with 24-h dietary recall surveys from 465 women in Tanzania.ResultsWe show that people with more unclassified tree cover (i.e., individual trees and small forest patches) in their nearby surroundings have more adequate protein, iron, zinc, and vitamin A intakes. We also find that having a nearby forest under Participatory Forest Management (PFM) system is associated with higher adequacy levels of energy, iron, zinc and vitamin A. By contrast, tree cover within other types of forest (e.g., Government Forest Reserves and Government Forest Plantations) is not positively associated with people’s dietary quality.ConclusionsOur key finding is that having individual trees, smaller forest patches and/or forest under PFM in close proximity is more beneficial for people’s diets than other types of established forests. Our results highlight the nutritional importance of trees outside established forests and question the often-assumed benefits of forests if these are made inaccessible by social barriers (e.g., legislation). Finally, our results emphasize the need to distinguish between different forest management systems when studying forest-diet linkages.

Diversity pattern of Symplocos tree species in China under climate change scenarios: Toward conservation planning

Symplocos, a genus rich in endemic and keystone species in China's subtropical forests, plays a vital role in maintaining biodiversity. Climate change impacts on Symplocos trees affect ecosystem composition, dynamics, and functions. This study delves into the potential ramifications of climate change on the distribution and richness of Symplocos species across China under different climatic conditions. A comprehensive analysis was conducted using occurrence records of 29 species of Symplocos, focusing on habitat suitability modeling and spatial analysis, to demonstrate the possible effects of climate change on the distribution and diversity patterns of Symplocos species in China. Environmental data, including bioclimatic variables, were collected, and the future climate scenarios were projected using the combined average of the two global climate models. Four modeling algorithms were applied in an ensemble species distribution models to assess the distribution of Symplocos species and decipher the pattern of species richness and endemism. The results indicate high accuracy and performance of the models with a mean AUC of 0.94 and TSS of 0.77, particularly the random forest. The analysis identified key bioclimatic variables influencing Symplocos species distribution, with precipitation patterns (precipitation of driest month and precipitation of warmest quarter) and temperature variability (temperature mean diurnal range) playing significant roles. Predictions suggest a reduction in Symplocos species richness over the next six decades, particularly in southern and southwestern China, with potential gains in other regions. Overall, this study highlights the vulnerability of Symplocos species to climate change and underscores the importance of proactive conservation efforts and forest plantations to mitigate future loss in Symplocos species diversity.

Labile Fraction of Organic Carbon in Soils from Natural and Plantation Forests of Tropical China

Labile organic carbon (LOC) is a key driver of forest ecosystem function and may mitigate global climate change through carbon sequestration. To explore the accumulation of LOC in tropical forest soils, we sampled from both planted and natural forests in Hainan Province, the southernmost province of China. We analyzed the concentrations of total organic carbon (TOC) and LOC and characterized various physicochemical properties such as pH and soil texture to understand their inter-relationships in tropical natural and plantation forests. Although the TOC concentration was higher in plantation forests (88.61 g/kg) than in natural forests (68.73 g/kg), the LOC concentration was higher in natural forests (5.12 mg/g) than in plantation forests (4.07 mg/g). Over a depth range of 0–50 cm from the surface, both forest types showed decreasing TOC and LOC concentrations with increasing soil depth, indicating surface aggregation. The soil is slightly acidic and primarily composed of sand particles. Correlation analysis showed a highly significant negative correlation between LOC concentration and soil pH in both forest types (p < 0.01). Soil LOC was positively correlated with soil clay and silt particles and negatively correlated with sand particles. This study provides valuable insights into soil carbon sequestration in tropical rainforest ecosystems in both plantation and natural tropical forests.

Soil Chemical and Physical Properties in Taungya and Non-Taungya Plots at Sao Hill Forest Plantation, Tanzania

This study compared soil physical and chemical properties in Tungya and Non-Taungya plots at Sao Hill Forest plantation, Tanzania. Soil samples were collected from 0-20cm depth in February and May Using a zigzag pattern to ensure representative coverage. Physical properties (bulk density, porosity, Soil moisture content, soil texture) and chemical properties (soil pH electrical conductivity, total nitrogen and available phosphorous) were analyzed using standard laboratory methods. Results showed significant differences between the two management practices. In February Non-Taungya plots had higher bulk density(1.33±0.151/cm3) compared to Taungya plots (1.16±0.107 g/cm3; p<0.001), while Taungya plots showed higher porosity (56.12%±4.06p<0.001). May sampling also revealed differences with non-Taungya plots maintaining higher bulk density (1.32±0.15 g/cm3) compared to Taungya plots (1.08±0.09 g/cm3); p<0.001). Soil texture analysis showed no significant differences in sand content between treatments. However, silt content was significantly higher in Taungya plots (13.27 ± 3.849%) compared to non-Taungya plots (10.69 ± 3.23%; p=0.007), while clay percentage did not differ significantly. Soil chemical properties, non-Taungya plots had higher pH (4.67±0.47) compared to Taungya plots (4.3±0.22; p<0.001) while electrical conductivity (0.04±0.04 dS/m) compared to Taungya plots (0.01±0.01 dS/m; p<0.001). Taungya plots showed higher total nitrogen (0.04±0.01%; p<0.0031) compared to non-Taungya plots (0.035±0.01%). In additional May available phosphorous in Taungya plots was (3.95±0.55 mg/kg; p<0.001) compared to non-Taungya plots (1.97±0.32 mg/kg). These results suggest that Taungya practices significantly influence soil properties, potentially impacting soil quality and forest productivity. The study provides valuable awareness for sustainable forest management and highlights the need for long-term monitoring of soil properties under different management systems in plantation forests

Does Bark Anatomy Influence the Selection of Woody Medicinal Plants in Seasonal Dry Forests from Brazil?

Does Bark Anatomy Influence the Selection of Woody Medicinal Plants in Seasonal Dry Forests from Brazil?

Rainfall interception in temperate evergreen broadleaved forest and Japanese cypress plantation with abundant lower-layer vegetation in south-west Japan

ABSTRACT The interception of rainfall in conifer plantations has been intensively studied. However, research on broadleaved forests is limited, although the broadleaved forests dominate approximately half of forest area in Japan. Here, we compared the throughfall and stemflow of each vegetation layer to clarify interception in a naturally regenerated temperate evergreen broadleaved forest (lucidophyllous forest) and a Japanese cypress plantation over a three-year period. Both forests were approximately 100 years old and had abundant lower-layer vegetation. We found that approximately a quarter of rainfall was intercepted in both forests, although the half of that interception in the Japanese cypress plantation was owing to the abundant lower-layer vegetation. This indicated that the interception in the evergreen broadleaved forest was twice that of the Japanese cypress upper canopy. The well-developed layer structure in the evergreen broadleaved forest efficiently intercepted rainfall. From the point of view of water resource management, this study implies that both evergreen broadleaved forests and Japanese cypress plantations with abundant lower-layer vegetation can decrease the amount of water infiltrating soils.

Characterizing annual leaf area index changes and volume growth using ALS and satellite data in forest plantations

While Leaf Area Index (LAI) is critical for understanding forest canopy, photosynthesis and forest growth, traditional field-based LAI measurements are laborious and costly. Remote sensing offers a practical alternative for extensive assessments. Satellite imagery provides broad-scale, long-term monitoring; however, may lack detail needed to guide specific forest management actions. Conversely, Airborne Laser Scanning (ALS) provides accurate LAI estimates at fine spatial detail but is limited by cost and temporal monitoring constraints. Combining ALS data with satellite observations could enhance plantation management decisions by balancing extensive coverage with detailed observations. This study explores the integration of ALS and satellite remote sensing as a comprehensive alternative for assessing LAI and stand volume growth rate (m3/ha/year) in operational Pinus radiata plantations in central-south Chile. Our approach comprised four major steps. First, we applied the Beer-Lambert law using ALS vertical profiles to estimate LAI across a forest plantation (LAIALS). We found that ALS accurately estimated LAI across 121 plots (R2 = 0.82 and RMSE = 0.51). Second, we built a simple linear regression to link LAIALS with the Normalized Difference Moisture Index (NDMI) derived from surface reflectance information from the Landsat/Sentinel-2 satellites, resulting in an R2 of 0.53 and an RMSE of 1.17. This step showed a higher correlation with satellite data compared to using only ground-based LAI estimates (R2 = 0.38; RMSE = 1.18). Third, we transformed biweekly NDMI time series to LAI, then derived peak annual LAI as an indicator of mean annual increment (MAI) (R2 = 0.51; RMSE = 5.27 m³/ha/year). This allowed us to characterize stand growth and LAI on a yearly wall-to-wall basis. Throughout the modelling steps, we incorporated error propagation, allowing final estimates to be error bounded. This integrated approach serves as a tool for identifying and visualizing growth irregularities, guiding adaptive management strategies to maintain or enhance stand productivity over time.

Fertilization-induced greenhouse gas emissions partially offset carbon sequestration during afforestation

Newly-planted forests require careful management to ensure the successful establishment of young trees; this can include herbicide application, irrigation, fertilization, or a combination of these treatments. The global rise in nitrogen (N) fertilizer application in managed forest plantations is driven by policies aiming at rapid tree growth and carbon sequestration as a strategy to tackle climate change. However, the impact of N-fertilizer on production and consumption of greenhouse gases (GHG), such as carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) is poorly understood, particularly when combined with irrigation. As a result, assessing forest GHG balance is key to defining effective climate mitigation strategies through afforestation projects.This study assessed the response of GHG fluxes to irrigation and fertilization on recently afforested lowland arable land in central England, across loamy and sandy loam soils. The application of 180 kg ha−1 of N via an irrigation system, aimed at enhancing wood production and C sequestration, resulted in an increase of CO2 and N2O emissions for both soil types. Particularly, the N2O emission factors (EF; kg N2O/kg N applied) for loamy and sandy loamy soils were 3.9% and 2.1%, respectively, higher than the IPCC default estimate of 1% for agricultural and forest land. Furthermore, both sandy loam and loamy soils showed a distinct transition from being CH4 sinks to sources. Thus, the combined application of irrigation and N-fertilizer had a significant impact on the total Global Warming Potential (GWP), which increased by 34% and 32% for sandy loam and loamy soil, respectively, when compared to their controls. Despite a significant increase in tree growth under fertilized conditions, the offset potential was only partial, highlighting the net contribution to GHG emissions. The outcomes of this study emphasise the potential for significant “carbon-equivalent-debt” from afforestation supported in its early years by irrigation and fertilization.

Recreational Assessment of Green Belt Forests of the Ulaanbaatar City

The classification of forest vegetation of the Tuul river basin within the green belt of the Ulaanbaatar city. Two associations (Linnaeo borealis–Pinetum sibiricae and Vaccinio vitis-idaeae–Laricetum sibiricae) were classified Vaccinio–Piceetea. Diagnostic signs and characteristics of the ecological and geographical peculiarities of the units were presented, anthropogenic transformation was assessed. To determine the models of succession processes, the series of permanent sample plots were established in the communities of the Linnaeo borealis–Pinetum sibiricae association, located at different distances from the city, in taxation units with unequal intensity of recreational load. Recreational forest assessment was calculated according to the approach by V.S. Romanov and L.N. Rozhkov (1974). In the Linnaeo borealis–Pinetum sibiricae association, large areas were occupied by moderately transformed communities. The Vaccinio vitis-idaeae–Laricetum sibiricae association is characterized by being weakly transformed forests. Different stages of anthropogenic pressure were formed serial communities, unequal in structure and species diversity. Serial plant communities of allogeneic succession were developed according to 2 models of geitogenesis — tolerance (Linnaeo borealis–Pinetum sibiricae ↔ Rhytidium rugosum; Linnaeo borealis-Pinetum sibiricae ↔ Chamaenerion angustifolium) and inhibition (Linnaeo borealis–Pinetum sibiricae ↔ Betula rotundifolia). A comprehensive assessment of the recreational potential was based on three indicators: natural conditions, air hygiene and landscaping. All activities aimed at increasing the recreational potential should contribute to the improvement of these indicators. A prerequisite for increasing the recreational forest assessment should be functional zoning of the territory with the allocation of infrastructure, walking and sanitary protective zones. Forest management is of great importance in increasing the recreational potential of forests. The forest management project for the organization of recreational forests should be aimed at the formation of sustainable and aesthetically attractive forest plantations.

Beta diversity subcomponents of plant species turnover and nestedness reveal drivers of community assembly in a regenerating subtropical forest.

Secondary forests represent a significant proportion of global forest cover, with over 70% of forests in East Asia classified as regenerating. While succession has been studied extensively in temperate systems, trajectories of subtropical succession remain poorly characterized in highly disturbed, urban-adjacent forests. Investigating the additive beta diversity components of turnover and nestedness may reveal community assembly mechanisms driving secondary succession. The present study investigates plant community assembly along a successional gradient from 7 to 70 years following the onset of succession in secondary subtropical forests in Hong Kong, China. Plant survey data for 28 plots were analysed, generating additive Simpsons turnover and nestedness beta diversity metrics. Dissimilarity matrices were generated and modelled as a function of environmental matrices including forest plant community age (years following onset of secondary succession), inter-community distance (metres), and soil moisture saturation (%) across three elevational bands using generalized dissimilarity models. Nonmetric multidimensional scaling of plant communities was conducted with Bray-Curtis dissimilarity matrices. Inter-community distance and successional age differentially influenced plant species turnover between lowland and Montane forest types. Models of nestedness found that plot age and soil moisture saturation were significant drivers of nestedness patterns in plant communities across elevational classes. Turnover represented a higher proportion of Sorensen beta diversity than nestedness, while ANOSIM found significant differentiation between plant communities at different successional stages. Turnover patterns suggest a deterministic model of community assembly, with strong patterns of species replacement between communities at fine spatial scales and successional stages, as well as clear compositional shifts between lowland and montane forest types. NMDS analysis and functional compositional assessments suggested a transition from early successional communities with a high proportion of shrub species, to later successional communities with a higher proportion of tree species, with an increase in species turnover with greater age dissimilarity.

Accumulation Radiocesium (137cs) By Plants of the Dnipro River’s Floodplain Ecosystems after Chernobyl Contamination

The analysis of radiocesium (137Cs) accumulation by plants of forest, marsh, meadow, psamophytic, and ruderal communities in the Dnipro River floodplain (Ukraine) was carried out. The species specificity of radiocesium accumulation by plants of specific biotopes and the direct dependence of the plant accumulation coefficient on the density of biotope contamination with radionuclides were confirmed. Differences in different radiocesium accumulation by plants of different ecosystems are probably related to the fact that the bioavailability of radiocesium strongly depends on soil properties. In the analyzed statistical model, the processes of accumulation and dissipation of 137Cs are significant.

The Characteristics and Variation of the Golden Eagle Aquila chrysaetos Home Range

Satellite tracking allows for novel investigations into golden eagle home range characteristics. Understanding home range characteristics is important for conservation and for assessing the potential impact of landscape changes from forest planting, wind farms, etc. Small sample sizes, inconsistent definitions and methods restricted several previous studies. Our study involved 69 resident tagged eagles with over one year of data across five Scottish regions. Home range size was estimated from 95% isopleth contours extracted from Utilisation Distributions. Above a small threshold, estimated range size was not affected by the number of records but at least one year of data is required, largely because of the breeding and non-breeding seasonal differences. There were no significant range size differences between birds tagged as range holders and those previously tagged as nestlings. Across four regions, with considerable intra-regional variation, planar 95% isopleths did not differ (medians, km2): Argyll 58.9, Northwest Highlands 61.7, Northeast Highlands 89.3, South of Scotland 91.9. Ranges in the isolated Outer Hebrides region were exceptionally small, at 24.0 km2. Estimated range area was usually reduced to 70–80% of the planar area when restricted to usable habitat, as estimated by the Golden Eagle Topography (GET) model. Applying measures of known unsuitable habitat (closed-canopy commercial forest and wind turbines) further reduced usable open land. Loss of otherwise suitable habitat was substantially due to commercial forest. Larger ranges had larger extents of suitable habitat (according to GET), with no apparent optimum of preferred GET habitat. Range size was not different across a year between the sexes. Breeding ranges were smaller, and females’ breeding ranges were much smaller than those of males, but larger than males’ ranges in the non-breeding season. Breeding attempt duration was probably also influential. Our study provides novel insights into golden eagle home range characteristics and can guide further research and practical applications.

How did the diversity of woody plants in urban forests vary with the urban-rural gradient in Qingdao, China?

The distribution and diversity of woody vegetation are crucial for understanding the structure and ecology of urban forests. As urbanization accelerates, the construction and composition of urban forests vary significantly along the urban-rural gradient. Qingdao's urban forests offer an opportunity to test the relationship between the diversity of woody plants and the urban-rural gradient. We classified the urban-rural gradient using imperviousness and construction time, then investigated the diversity of woody plants in Qingdao's urban forests under different urban-rural gradients and tested the reasonableness of their allocation. Correlation analysis found that the diversity index of woody plants in urban forests was highly connected to the urban-rural gradient (by imperviousness: rMargalef Index = −0.589, rShannon-Wiener Index = -0.373, rPielouIndex = −0.170, rSimpson Index = 0.272/by construction time: rMargalef Index = −0.530, rShannon-Wiener Index = −0.360, rPielouIndex = −0.148, rSimpson Index = 0.272/0.174). With a decrease in urbanization density, the Margalef (H), Shannon-Wiener (H′), and Simpson (D) indices all decreased while the Pielou (E) index increased. The four diversity indices showed a substantial correlation with one another, but not with the Margalef and Pielou indices. The analysis utilizing the 10/20/30 rule of empirical demonstrates a clear irrationality in allocating shrub species in Qingdao's urban forests, and the distribution of tree species is reasonable. Based on the study results, strategies for optimizing and enhancing urban forests in Qingdao are proposed for different urban-rural gradients, respectively. This study can provide a scientific framework for urban biodiversity conservation and management in Qingdao and serve as a guide for urban forests and greening with comparable climates.