Increasing Canopy Cover Research Articles

High-resolution mapping of grassland canopy cover in China through the integration of extensive drone imagery and satellite data

Canopy cover is a crucial indicator for assessing grassland health and ecosystem services. However, achieving accurate high-resolution estimates of grassland canopy cover at a large spatial scale remains challenging due to the limited spatial coverage of field measurements and the scale mismatch between field measurements and satellite imagery. In this study, we addressed these challenges by proposing a regression-based approach to estimate large-scale grassland canopy cover, leveraging the integration of drone imagery and multisource remote sensing data. Specifically, over 90,000 10 × 10 m drone image tiles were collected at 1,255 sites across China. All drone image tiles were classified into grass and non-grass pixels to generate ground-truth canopy cover estimates. These estimates were then temporally aligned with satellite imagery-derived features to build a random forest regression model to map the grassland canopy cover distribution of China. Our results revealed that a single classification model can effectively distinguish between grass and non-grass pixels in drone images collected across diverse grassland types and large spatial scales, with multilayer perceptron demonstrating superior classification accuracy compared to Canopeo, support vector machine, random forest, and pyramid scene parsing network. The integration of extensive drone imagery successfully addressed the scale-mismatch issue between traditional ground measurements and satellite imagery, contributing significantly to enhancing mapping accuracy. The national canopy cover map of China generated for the year 2021 exhibited a spatial pattern of increasing canopy cover from northwest to southeast, with an average value of 56 % and a standard deviation of 26 %. Moreover, it demonstrated high accuracy, with a coefficient of determination of 0.89 and a root-mean-squared error of 12.38 %. The resulting high-resolution canopy cover map of China holds great potential in advancing our comprehension of grassland ecosystem processes and advocating for the sustainable management of grassland resources.

Validation of the vertical canopy cover profile products derived from GEDI over selected forest sites

Canopy cover (CC) quantifies the proportion of canopy materials projected vertically onto the ground surface. CC is a crucial canopy structural variable and is commonly used in many ecological and climatic models. The vertical CC profile product is currently available from the Global Ecosystem Dynamics Investigation (GEDI). However, detailed information about the accuracy and uncertainty of the GEDI vertical CC profile product remains limited. The objective of this study is to validate the GEDI CC product over selected forest sites using reference values derived from digital hemispherical photography (DHP), airborne laser scanning (ALS) point clouds, and simulated waveforms. The accuracy of CC was quantified and analyzed regarding GEDI observation conditions, waveform processing, and estimation methods. The results show that the GEDI total CC correlates well with those estimated from DHP, ALS, and simulated waveform data (r2 = 0.65, 0.71, and 0.71, respectively) but is systematically underestimated (bias = −0.05, −0.11, and −0.07, respectively) based on reference data. Compared with the ALS-estimated CC, needleleaf forest shows the highest correlation for vertical CC (r2 ≥ 0.65) and shrubland shows the lowest bias for total CC (bias = −0.13). The mean absolute error (MAE) of the GEDI CC decreases from 0.15 to 0.09 as the estimation height increases from ground to 35 m. The GEDI total CCs derived from the waveform interpretation algorithms A2 and A6 display the highest r2 (≥ 0.6) and smallest RMSE (≤ 0.23) compared to those of the other algorithms. The CC accuracy increases with beam sensitivity and decreases with increasing canopy cover. The GEDI CC was improved at moderate CC values using a canopy-to-ground backscattering coefficient ratio (ρv/ρg) determined with the regression method. The partial difference between GEDI CC and ALS CC is attributed to definitional discrepancies. Further improvement of the CC algorithm can be made by using vegetation-specific waveform processing algorithms and realistic ρv/ρg values.

Prescribed fire influences occupancy and abundance of grassland-nesting passerines overwintering in pine forests of Central Louisiana

We surveyed longleaf (Pinus palustris) and loblolly pine (P. taeda) stands burned within 0–7 years to examine the influence of prescribed fire on grassland-nesting passerines that overwinter in pine forests of central Louisiana, USA. We modeled occupancy and abundance of Bachman’s sparrows (Peucaea aestivalis), Henslow’s sparrows (Ammodramus henslowii), and sedge wrens (Cistothorus stellaris) in relation to stand type, years since burn, and site-scale vegetation conditions. We also used analysis of variance to compare vegetation conditions across study sites and detection points for these three species. Bachman’s sparrow occupancy was 3.7 times greater in longleaf stands compared to loblolly stands and decreased 30 % with every 10 % increase in canopy cover. We also found a positive relationship between Bachman’s sparrow density and the density of herbaceous plants in both stand types. Henslow’s sparrows used herbaceous vegetation within longleaf pine stands burned 0–2 years ago that was significantly taller than what we observed at the site scale, but the best fit models for Henslow’s sparrow occupancy (maximum vegetation height, bare ground, herbaceous cover) had overlapping confidence intervals. Henslow’s sparrow density was positively associated with bare ground and negatively associated with litter depth. Sedge wren occupancy decreased 50 % with every 10 % increase in canopy cover. Sedge wren density increased with increasing percent herbaceous cover, however, the 95 % confidence intervals for this relationship largely overlapped. Our study reiterated the importance of frequent (<3 years) prescribed fires to maintain habitat used by grassland-nesting passerines that overwinter in southeastern pine forests.

Impacts of ash tree removals on summer daytime temperatures in Madison, Wisconsin

Maintaining and increasing canopy cover is frequently promoted as a strategy for mitigating excess heat in cities. However, the impact of changing tree cover on surrounding air temperatures is often unpredictable and can depend on tree species, size, shape, and location. In this study, we explore whether the removal of ash trees in one downtown neighborhood in Madison, Wisconsin affected surrounding air temperatures at small spatial scales (15 to 35 m). We used a bicycle-mounted temperature and radiation sensor to repeatedly record high-frequency observations along four transects. We observed no discernible difference between daytime air temperatures near locations surrounded by tree removals and temperatures at locations without any nearby tree removals. Overall, across the four clusters of streets that were monitored, proximity to mature ash trees did not correlate to reduced air temperatures. Attempts to model temperature as a function of surrounding land cover and street tree characteristics all had poor predictive power (R2 ranged from 0.01 to 0.54), and explanatory variables related to tree cover were never statistically significant. The finding that the removal of ash trees did not impact daytime air temperatures patterns at the neighborhood scale suggests that the most densely developed streets in Madison may not easily support sufficient canopy cover to experience tree-induced cooling, underscoring the importance of pursuing a variety of strategies to mitigate urban warming.

Urban forest species selection for improvement of ecological benefits in Polish cities - The actual and forecast potential

Trees in cities perform important environmental functions: they produce oxygen, filter pollutants, provide habitat for wildlife, mitigate stormwater runoff, and reduce the effects of climate change, especially in terms of lowering temperatures and converting carbon dioxide from the atmosphere into stored carbon. Generally, to increase the environmental benefits of urban forests, the number of trees is increased, directly influencing the canopy coverage. However, little is known about potential of modifying the species composition of urban tree communities in order to increase ecological benefits. Planting and managing trees to increase canopy is particularly challenging in city centres, where the dense, often historic infrastructure of buildings and roads do not allow for a significant increase in greenspace. Estimations of canopy cover obtained through i-Tree Canopy analysis unveiled significant potential to increase canopy cover in historical urban areas in Polish cities from 15-34% to 31–51%. This study models the ecological benefits of urban forests in Polish cities, focusing on how different species compositions can enhance environmental functions such as carbon sequestration and pollution filtration. Two main scenarios were analyzed: one involving the addition of trees based on the most common species currently planted (“standard option” SO), and another incorporating changes to the species composition to enhance ecological benefits (“city specific option” SCO). Acer platanoides (14.5%) and Tilia cordata (11.45%) were the most frequently species of Polish cities. Betula pendula, Quercus robur, Robinia pseudoacacia, Fraxinus excelsior, Acer pseudoplatanus, Aesculus hippocastanum and Acer campestre were also common species in urban forest communities (up to 5%). The diverse range of tree species in Polish cities contributes significantly to the overall carbon sequestration potential. The results suggest that modifying species composition could significantly increase carbon sequestration rates by 47.8%–114% annually, with the city specific option (SCO) being the most effective in enhancing carbon sequestration potential. This highlights the importance of strategic species selection in urban forestry practices to maximize environmental benefits and mitigate climate change effects.

Mangrove Cover and Extent of Protection Influence Lateral Erosion Control at Hybrid Mangrove Living Shorelines

Erosion poses a significant threat to coastal and estuarine environments worldwide and is further exacerbated by anthropogenic activities and increasing coastal hazards. While conventional engineered structures, such as seawalls and revetments, are commonly employed to protect shorelines from wave impact and erosion, they can also cause detrimental environmental effects. By creating/restoring coastal habitats with engineered structures, hybrid living shorelines offer coastal protection and other co-benefits. Using aerial imagery, we studied the rates of shoreline change before and after living shoreline installation, and between living shorelines and adjacent bare shorelines in three estuaries in New South Wales, Australia. Mangroves had established behind most rock fillets and displayed a trend of increasing canopy cover with fillet age. In the first 3 years since installation, the rates of lateral shoreline change reduced from − 0.20, − 0.16, and − 0.10 m/year to − 0.03, − 0.01, and 0.06 m/year in living shorelines in Hunter, Manning, and Richmond Rivers, respectively. However, when compared to control shorelines, the effectiveness in reducing erosion varied among living shorelines with mean effect sizes of 0.04, − 0.28, and 1.74 across the three estuaries. A more positive rate of shoreline change was associated with an increasing percentage of mangrove canopy area and an increasing length of protected shoreline at wide channels. While hybrid mangrove living shorelines are a promising solution for mitigating erosion and creating habitats at an estuary-wide scale, they may also contribute to downdrift erosion, emphasising the importance of considering site-specific hydrogeomorphology and sediment movement when installing living shorelines.

Residual canopy cover provides buffering of near-surface temperatures, but benefits are limited under extreme conditions

Increasing summer temperatures and higher probabilities of extreme heat events have led to concerns about tree damage and mortality. However, insufficient attention has been given to conditions leading to heat-related regeneration failures in temperate forests. To address this, managers need to understand how microclimate varies under a range of overstory conditions. We measured air temperatures at 2 cm above-ground underneath a gradient of canopy cover on south-facing slopes in recently thinned Douglas-fir stands in western Oregon, USA. To expand the ecological relevance of these data to impacts on regeneration, we created the stress degree hours (SDH) metric, representing the amount of time—and by how much—temperatures exceeded biologically relevant stress thresholds. Overall, for every 10% increase in canopy cover, maximum temperatures at 2 cm were 1.3 °C lower, the odds of temperatures exceeding stress thresholds for conifer regeneration declined by a multiplicative factor of 0.26, and the total of SDH decreased by 40%. These reductions are large enough to be worthy of attention when managing for tree regeneration. However, data collected during the Pacific Northwest Heat Dome in June 2021 indicate that with various climate change scenarios and heatwave occurrences, temperatures will be unfavorable for regeneration regardless of overstory cover.

Impact of Cropland Management on Invertebrate Richness and Abundance in Agroforestry Systems in Bali, Indonesia

The intensive management of cropland refers to a reduction in habitat complexity (i.e., shade tree cover, tree species richness, crop species richness) to gain more profits. This usually entails a decrease in biodiversity, but agroforestry systems have been shown to provide a solution to the need for profits while maintaining biodiversity and ecosystem services. Invertebrates are important bioindicators since they are not just affected by a decrease in habitat complexity; they are also key for the maintenance of ecosystems given their ecological roles. We aimed to understand how agricultural intensification impacted invertebrate abundance and richness in an agroforestry system in Bali, Indonesia. We set up 53 × 25 m2 plots and collected data via pitfall and pan traps. We linked those data to vegetation data (canopy cover, tree species richness, crop species richness), habitat type (rustic vs. polyculture), and productivity. Overall, we found that the abundance and richness of invertebrate taxa were positively influenced by increasing canopy cover and crop and tree species richness. This supports the habitat heterogeneity hypothesis, which indicates that increased habitat complexity promotes higher invertebrate species richness and abundance. The abundance and richness of certain invertebrate taxa, including agents of biocontrol, were shown to increase in plots with higher yields, thus solidifying the important role of invertebrate communities in the provision of ecosystem services. Harvesting crops from complex agroforestry systems ensures a sustainable income for local communities as well as habitats for invertebrates.

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.

Morphological Strategies in Ant Communities along Elevational Gradients in Three Mountain Ranges

Species traits often vary in a coordinated manner, making up an ecological strategy comprised of suites of interrelated traits. Environmental gradients, such as those along elevational gradients, provide an ideal venue in which to examine variation in ecological strategies with the environment. We examined variation in the morphological strategies of ants along elevational gradients on thirteen mountains across three mountain ranges in central and south-eastern Australia. We pitfall-trapped ants, counted and identified workers and measured morphological traits. Most species showed a hump-shaped relationship between occurrence and elevation, and several responded to microhabitat variables. Morphological traits varied along two key axes: “gracility”, where high values indicated longer-legged species with dorsally positioned eyes and smooth, bare cuticles; and “size and darkness”, where species with high values were larger and darker. Analysis of assemblage-weighted means revealed that gracility decreased with temperature and increased with precipitation, suggesting links with desiccation tolerance. Size and darkness increased with UV-B, declined with increasing canopy cover and peaked at mid-temperatures. We thus detected strong shifts in dominant morphological strategies along our elevational gradients. However, the multifunctionality and interrelatedness of traits and the covariance of climatic factors may make isolation of the function of individual traits difficult. Further, the predictive power of our models may be limited in the context of novel environments predicted under global change.

Latewood intra-annual density fluctuations indicate wet summer conditions and enhanced canopy activity in a Mediterranean ring-porous oak

Summary The climatic significance and ecosystem implications of latewood intra-annual density fluctuations (IADFs) are still not fully understood in Mediterranean ring-porous oak species. To solve this issue, we investigated: (i) the climate drivers of radial growth and latewood IADFs in the Mediterranean oak Quercus faginea, and (ii) whether they were correlated to increased canopy cover and greenness as recorded by the Normalized Difference Vegetation Index (NDVI). IADFs were formed in the mid to late latewood and they were characterized by rows of parenchyma cells. Such IADFs were uncommon and only present in 30–50% of sampled trees during 1999 and 2014, both years characterized by high precipitation in late July and early August. This relationship between IADFs formation and summer wet conditions differed from the conditions that enhance Q. faginea annual growth, wet winter-spring conditions, and low summer temperatures. Furthermore, IADFs formation showed a positive relationship with August NDVI values, indicating a correspondence of canopy greenness with secondary growth reactivation. We conclude that latewood IADFs in Q. faginea are a robust proxy of rare late-summer wet conditions and enhanced canopy activity as reflected by increased August NDVI values. Further monitoring of xylogenesis in other Mediterranean hardwoods along climatic gradients is suggested to mechanistically explain IADF production in seasonally dry biomes.

Modelling Four Neighbourhood-Scale Urban Forest Scenarios for 2050: Vancouver, Canada

Abstract Background Urban forests are increasingly recognized as important tools in climate change mitigation and adaptation, prompting many cities to set tree canopy cover targets. However, current gaps in knowledge include understanding relationships and the feasibility of maximizing benefits between urban greening and other climate actions, such as densification. This study offers a data-driven and manageable framework for assessing current and anticipated future urban forestry conditions using spatial tree and built-form models. Methods We spatially modelled 4 planting scenarios for increasing tree canopy cover by 2050 in a densifying neighbourhood in Vancouver, Canada, with low (&lt; 10%) existing tree canopy. Results Based on mortality assumptions, we aged out and replaced 1,853 to 2,445 trees since 2020. We added 6,079 to 11,726 trees across the 4 scenarios (10,228 to 15,823 total), increasing canopy cover from 7% in 2020 to a maximum of 16% by 2050. Despite rigorous tree planting, we were unable to achieve a 30% canopy cover target at neighbourhood scale. Tree replacement due to mortality was a major contributor to decreased canopy cover and volume in future scenarios. The 31% to 34% reduction in future canopy cover due to the replacement of aged-out trees was driven by changes on private parcels. Conclusion Our systematic framework for generating and spatially modelling trees in a simulated future neighbourhood provides an opportunity for iteratively assessing multiple potential tree planting configurations. Future work for this project includes investigating social-ecological, outdoor shading, and building energy implications of various modelled urban forest strategies.

Achieving the Urban Tree Trifecta: Scenario Modelling for Salubrious, Resilient, and Diverse Urban Forests in Densifying Cities

AbstractBackgroundUrban forests can provide nature-based solutions (NBS) to complex climate-change challenges via the provision of ecosystem services such as shade and cooling that offset increased risks of chronic diseases and excess mortality. They also confer indirect health benefits by providing regulating ecosystem services that can facilitate climate-change mitigation efforts: increased shade can encourage shifts to lower-carbon transportation methods such as walking and cycling, for example. However, in order to ensure that urban forests are both resilient to threats and confer the maximum possible benefits, we must be able to project decades into the future in order to understand the implications of current urban forestry decisions.MethodsThis study outlines a framework for creating urban-forest scenario models and reports the results of a case study conducted to highlight the ways in which decisions made at each stage of the scenario-development process impact its outcomes and application. Our case study focused on a neighbourhood in Vancouver, Canada, that is simultaneously undergoing urban densification and aiming to significantly increase canopy cover by 2050. Three distinct aims were identified for the case study: maximizing public-health benefits, selecting climate-resilient tree species, and integrating planting across public and private lands to advance diversity. To achieve these aims, baseline information on the neighbourhood’s existing tree network was collected, entered into GIS software, and delineated based on a set of pre-identified characteristics. Next, a list of climate-adapted species was developed. This climate-adapted species list was then virtually “planted”across the neighbourhood, using a combination of machine-based and manual planting techniques. Finally, the resulting scenario model was quantitatively assessed to understand its composition and impacts.ResultsOur study demonstrates that a salubrious, resilient, and diverse urban forest can be created via a strategic program that complements extant trees in the public domain with planting programs along blue-green streets and on private property.ConclusionsAchieving the urban tree trifecta will require collaboration among municipal departments and the development of a range of public and private initiatives, but it has the potential to maximize nature-based solutions in cities facing rapid shifts due to densification and climate change.

The effects of forest composition and management on evapotranspiration in the New Jersey Pinelands

Forests deliver contrasting ecosystem services in relation to water, both provisioning it through filtration and recharge, and consuming it through evapotranspiration. Understanding forest evapotranspiration is critical for landscapes managed in part for the social benefits of their water provisioning ecosystem services. We used the flux disaggregation algorithm for the Atmosphere-Land Exchange Inverse model (DisALEXI) with remotely sensed data to characterize landscape-scale evapotranspiration at 30-m spatial resolution over the forested coastal plain Pinelands of southern New Jersey, USA. We examined changes in evapotranspiration due to forest compositional and cover differences, then evaluated the effects of three common management actions (thinning, seed tree regeneration, and prescribed burning) on stand evapotranspiration. Among various forest compositions, upland oak forests had the lowest annual evapotranspiration, while Atlantic white cedar had the highest. In uplands, increasing proportions of conifers increased evapotranspiration, as did increased canopy cover in conifer stands. Seed tree harvests reduced evapotranspiration for about 13 years, while thinning reduced forest water use for approximately six years. Prescribed fires had variable effects, but their typical application did not reduce evapotranspiration for a complete growing season. Our research can help to inform models and decision-making around forests and landscape water yield.

Heat pulse velocity method for determining water requirements in rainfed sweet cherry trees (Prunus avium L.)

It is imperative to possess a comprehensive understanding of the water consumption patterns of sweet cherry trees under rainfed conditions. This study investigates the water use of sweet cherry using the heat pulse velocity sap flow method. Tree response to drying soil conditions over two consecutive measurement periods (September 2017 to December 2018) in the eastern Free State, South Africa, is also evaluated. During the post-harvest period (December), there was a continuous increase in daily water consumption by trees, in conjunction with an increase in canopy cover, even though the crop load was reduced. Measured sap flow was positively correlated to net radiation, air temperature, and water vapour pressure deficit. The transpiration rates ranged from 1.2 to 3.5 L d-1 during the flowering stage (day of year, DOY, 244 – 270) and showed an increasing trend as the days progressed. During the ripening stage (DOY 271 – 292), transpiration rates decreased from 4.5 to 1.1 L d-1 over the 2018 season. This decreasing trend from the previous growth stage was due to soil drying and scorching weather conditions that led to trees experiencing water stress. Sap flow measurements, however, showed typical characteristics of the diurnal trend during selected days during varying weather conditions. The fraction of transpirable soil water (FTSW) threshold varied for different fruit growth stages and approached 1.0 for different stress levels. FTSW exceeded 0.4 when sweet cherry trees utilised stored soil water, while the transpiration rates declined during prolonged hot days. Moreover, the stress coefficient factor ranged between 0.45 – 0.65 for different growth stages. The daily soil water content varied, and soil evaporation was expected to increase during hot and dry days. In the early stage of a dry spell, soil water content did not directly affect the transpiration rate. Sweet cherry trees are susceptible to soil water deficit at different stages of fruit development. More research is required to understand transpiration as an irrigation management and planning indicator.

Bird functional and taxonomic diversity in xerophytic forests: contributing to balance bird conservation and livestock production

Biodiversity is increasingly dependent on the ecological state of agricultural and livestock systems. Here, we assess the relationship between bird functional and taxonomic diversity and forest structure along a gradient in grazing intensity in xerophytic forests in Central-East Argentina. We found that bird functional diversity responds more to forest structure variables than taxonomic diversity. Further, we found a non-linear response of functional and taxonomic richness to grazing intensity, peaking at intermediate intensity. Mature forests with older trees and low grazing intensity favored a wider range of bird traits, such as seed dispersal and cavity nesters. In particular, taxonomic and functional diversity significantly increased with increasing canopy cover and DBH. In contrast, shrub encroachment, high grazing intensity, and the decrease of tree density and cover were associated with reduced functional diversity, affecting various nesting, foraging, and habitat requirements of birds. We recommend preserving high canopy cover and older trees and maintaining low grazing intensities to create a synergy between livestock production and biodiversity conservation.

Are nurse plants useful for facilitating the reintroduction of mid- and late successional tree species in tropical montane cloud forests?

Background: In Mexico, where 50 % of the original Tropical montane cloud forest (TMCF) has been lost due to human activities, the restoration of these forests is essential.&#x0D; Questions and/or hypotheses: (1) L. styraciflua favors the survival and growth of Q. germana and M. schiedeana species (2) Are there competitive effects between nurses and beneficiary species? and (3) Is the magnitude of these positive/negative interspecific interactions affected by the canopy cover of nurses?&#x0D; Studied species: Liquidambar styraciflua L. (pioneer tree), Magnolia schiedeana Schltdl. (mid-successional tree) and Quercus germana Schltdl. &amp; Cham. (late-successional tree).&#x0D; Study site and dates: A fallow in Xilitla, state of San Luis Potosí, Mexico, between 2016 and 2018.&#x0D; Methods: Seedling of mid- and late-successional species were transplanted 0.3 m and 2 m away from the stems of pioneer tree (protected and unprotected saplings, respectively). Performance of the species were compared after two years and the effects of canopy cover of pioneer trees.&#x0D; Results: Pioneer trees facilitated the establishment probabilities of the mid-and late-successional ones. Increasing canopy cover of pioneer trees enhanced the establishment probabilities of both beneficiary species.&#x0D; Conclusions: Joint transplanting of pioneer trees with mid- and late-successional tree seedlings in their close vicinity is a strategy to favor the recovery of the ecosystem.

Factors influencing mammalian community occupancy in Dhorpatan Hunting Reserve, Nepal.

The decline in mammalian species diversity is increasing worldwide, with areas characterized by high human activities experiencing more prominent effects. Knowledge of spatial distributions of species and factors acting on them is necessary for effective management. We evaluated community-level occupancy of mammal species in Dhorpatan Hunting Reserve (DHR), Nepal using remote cameras during 15 March-15 June 2022. We used mammal species detections from remote cameras and multispecies hierarchical occupancy modeling to assess the effects of environmental and anthropogenic variables on community-level occupancy of detected mammal species. We identified a highly heterogeneous mammal species community at DHR with greatest detection probability (0.21) for red fox (Vulpes vulpes) and lowest (0.08) for blue sheep (Pseudois nayaur). Naïve occupancy ranged from 0.31 for giant-flying squirrel (Petaurista magnificus) to 0.84 for red fox. Mammal community occupancy increased with increasing canopy cover and number of livestock detections, but overall occupancy declined close to human settlements. The findings of this study can be used for developing policy at DHR for the management of mammal species through reducing the potential increase of human settlements or livestock grazing.

COMPARISON OF CANOPY COVER EFFECTS ON RAINFALL INTERCEPTION LOSS IN TROPICAL FOREST WITH HOMOGENOUS AND MIXED TREE SPECIES

This study was designed to determine the canopy cover, c of the tropical forest and explore its effects on the interception loss amount. The study area was a reserved forest Lagong Hill Forest Reserve, Kepong, Selangor, Malaysia, where two plots with an area of 400 m2 (20 m x 20 m) each have been set up to collect the data. In order to determine the measured interception loss, rainfall, throughfall, and stemflow data have been measured on site. The tree with a diameter at breast height (dbh) of more than 10 cm was selected in collecting the stemflow data. Twenty-five (25) locations have been chosen for the digital hemispherical photographs to be taken. The forest standing of the study area has been visualised by Stand Visualization System (SVS) method, and WinSCanopy 2009a and RGBFisheye.exe application software has been used to obtain the canopy cover values. In this study, the correlation between canopy cover and interception loss were obtained for both plots. It is found that the Lagong Hill Forest Reserve varied has a compact canopy density with canopy cover up to 95%. This condition will affect the canopy interception loss value ranging from 24.83% up to 64.72%. The canopy cover and interception loss correlation denote that the interception loss amount reduces whilst the canopy cover increases.

Canopy cover mediates the effects of a decadal increase in time since fire on arboreal birds

Wildfires impact animal populations directly, and indirectly through alteration of forest habitats. Recovery of populations and habitat structure occurs over time since fire, but knowledge is lacking about the relative importance of these processes as drivers of the occurrence of birds in fire-prone forests. We aimed to determine the extent to which canopy cover mediates the effects of a decadal increase in time since fire on the richness and occurrence of canopy bird species. We established sites at either short (5 years) or mid-range (16 years) time since fire in montane dry sclerophyll forests of south-eastern Australia. Canopy cover estimates were derived from airborne LiDAR data. Birds were surveyed using acoustic recorders, with the resulting data analyzed using Bayesian mediation models to partition direct (population processes) and indirect (canopy cover) effects of time since fire on canopy birds. The predictive accuracy of models representing partial mediation (direct and indirect effects) and complete mediation (indirect effects only) were then compared. The direct effects of wildfire on birds were minimal between five and 16 years since fire. Instead, indirect effects prevailed, with species richness and the occurrence of most canopy species increasing as canopy cover regenerated over time since fire. As these forests transition from short to mid-range time since fire, ongoing increases in canopy cover are of primary importance for birds. We recommend an approach to managing avian diversity that incorporates canopy cover in fire planning to optimize the retention of dwindling amounts of older forest under climate change.