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The savanna-type xerophytic forests of Neltuma caldenia are located bordering the Argentine humid pampas and have an area of 3 million hectares. Currently, the main economic activity is cattle breeding. The contribution of the livestock sector to greenhouse gas emissions is a cause of international concern. Agroforestry is presented as an important carbon sequestration strategy. The objective of the following work was to address, through modeling and field data, a carbon balance based on forest cover for a silvopastoral system in native forest. To do this, the herbaceous stratum was measured in different forest covers, weighted by a livestock use factor and by the estimated emissions from cattle in the region. The evolution of forest stand parameters was modeled using growth data obtained from dendrometers distributed at different tree densities. The projected values of the forest flight show that from 2.4 m2 ha−1 of basal area (BA), the captures of eq-CO2 in the total tree biomass exceed the emissions of livestock. If the capture of C by the stem biomass is considered, the compensation point, using the maximum emission category (lactating cow), is reached when the forest has a capture rate of 0.67 Mg C ha−1 year−1, a stock of 38.86 Mg C ha−1 of total biomass and a density of 17.5 m2 ha−1 of BA. It is concluded that managing the N. caldenia forest with adequate silvicultural management would allow the production of "carbon neutral meat." The balance did not consider the capture of C on the ground. [ABSTRACT FROM AUTHOR]

Seasonally Dry Tropical Forests (SDTFs) are situated in regions prone to significant water deficits. This study aimed to evaluate and quantify the dynamics and spatial patterns of vegetation and water bodies through the analysis of physical–hydrological indices for a remnant of FTSD between 2013 and 2021. Basal area, biomass, and tree number were monitored in 80 permanent plots located in two areas of an SDTF remnant with different usage histories. To assess vegetation and water resource conditions, geospatial parameters NDVI, NDWIveg, NDWI, and MNDWI were estimated for the period from 2013 to 2021. The observed patterns were evaluated by simple linear regression, principal component analysis (PCA), and principal component regression (PCR). Area 2 presented higher values of basal area, biomass, and number of trees. In area 1, there was an annual increase in basal area and biomass, even during drought years. The NDVI and NDWIveg indicated the vulnerability of vegetation to the effects of droughts, with higher values recorded in 2020. NDWI and MNDWI detected the water availability pattern in the study area. Physical–hydrological indices in the dynamics of tree vegetation in dry forests are influenced by various factors, including disturbances, soil characteristics, and precipitation patterns. However, their predictive capacity for basal area, biomass, and tree number is limited, highlighting the importance of future research incorporating seasonal variability and specific local conditions into their analyses. [ABSTRACT FROM AUTHOR]

Seasonally Dry Tropical Forests (SDTFs) are situated in regions prone to significant water deficits. This study aimed to evaluate and quantify the dynamics and spatial patterns of vegetation and water bodies through the analysis of physical–hydrological indices for a remnant of FTSD between 2013 and 2021. Basal area, biomass, and tree number were monitored in 80 permanent plots located in two areas of an SDTF remnant with different usage histories. To assess vegetation and water resource conditions, geospatial parameters NDVI, NDWIveg, NDWI, and MNDWI were estimated for the period from 2013 to 2021. The observed patterns were evaluated by simple linear regression, principal component analysis (PCA), and principal component regression (PCR). Area 2 presented higher values of basal area, biomass, and number of trees. In area 1, there was an annual increase in basal area and biomass, even during drought years. The NDVI and NDWIveg indicated the vulnerability of vegetation to the effects of droughts, with higher values recorded in 2020. NDWI and MNDWI detected the water availability pattern in the study area. Physical–hydrological indices in the dynamics of tree vegetation in dry forests are influenced by various factors, including disturbances, soil characteristics, and precipitation patterns. However, their predictive capacity for basal area, biomass, and tree number is limited, highlighting the importance of future research incorporating seasonal variability and specific local conditions into their analyses.

In almost all cases, forest inventories require the measurement of diameter at breast height (DBH) and tree height, which are essential for the quantitative study of trees and stand structure, as well as for estimating forest stand parameters. Taking into account the digitization trend, this article aims to address the possibility of using the Measure app, a free and common application integrated into the new smartphone models that use the iOS operating system, to measure DBH, by highlighting the impact of diameter measurement errors on tree- and stand-level basal area. To achieve our objectives, two rectangular plots of 1 ha each were established in an uneven-aged mixed forest from Eastern Carpathians. DBH on two orthogonal directions was measured for 888 trees using a caliper and the Measure app built-in operating system iOS 14 (Apple Inc., Cupertino, California, USA), and girth at the level of 1.30 m was measured using a tape. Stand basal area was also estimated by point sampling running 120 horizontal point samples with various basal area factors. The mean error (MEDBH), the absolute mean error (AMEDBH), and the root mean squared error (RMSEDBH) in the breast height diameters were calculated by species. DBH differences were tested using the paired samples t test and the related-samples Wilcoxon signed rank test. Furthermore, the correlation coefficient (R) and multiple R were computed by species to identify the relation between basal area error and various tree characteristics. Our study showed that there was a tendency to underestimate diameters when the app was used, and thus mean DBH was underestimated by 0.45–0.89 cm in the case of the conifers and by 0.17–0.71 cm in the case of the broadleaves. By using the iPhone Measure app, AMEDBH varied from 0.96 to 1.51 cm, while RMSEDBH varied between 1.15 and 1.92 cm. In the cases of the sessile oak and sycamore trees, no significant differences were found between DBH measured by caliper and by app, while for the other species, the differences were significant. Therefore, the ± 5% frequency of individual errors when estimating basal area was reduced by approximately half in the case of using the app as opposed to the caliper, and the risk of recording errors > 10% in tree basal area estimation was 26 times higher. For the most part, basal area error at tree level was determined by the error in DBH measurement, but tree size and the ovality of the cross-sections also contributed to a smaller degree. The tendency to underestimate DBH when the iPhone Measure app was used resulted in underestimating stand basal area by approximately 4.1%. Considering the DBH derived from girth measurement as reference, stand basal area was estimated by the iPhone Measure app with a difference of -6.50%. In contrast, point sampling produced better results using BAF = 4 m2ha− 1. Despite the fact that the iPhone Measure app is a convenient digital measurement tool, it still requires upgrades of certain details to achieve the accuracy of the caliper, so that in the near future this type of application can be used on a wider scale to collect field data related to tree diameter and height, as well as to estimate stand basal area. [ABSTRACT FROM AUTHOR]

Though essential in combating climate change, conserving biodiversity and providing myriad ecosystem services, urban parks in Africa, are challenged by rezoning, encroachment and other pressures. Furthermore, research on urban park tree diversity, dominant species and carbon stocks of parks in developing countries in Africa are scanty. This study assessed the carbon stocks, tree species diversity and stand structure in public parks within Kumasi metropolis. In each selected park, four 40 × 40 m plots were randomly sampled. The heights, diameters, and crown width of all woody vegetation with a diameter at breast height (DBH) greater than 10 cm, were measured and carbon stocks determined. The stand density (p = 0.0546), DBH (p = 0.004), total tree height (p = 0.01), basal area, and carbon stocks (p = 0.018) differed significantly among parks. The carbon stocks of the parks were 80.73 ± 8.77, 45.10 ± 4.83, 76.26 ± 30.19 and 9.59 ± 2.13 MgCha−1 at Kumasi Zoological Garden, KNUST Botanical Garden, Royal Golf Course, and Rattray Park, respectively. With an average of 53.88 ± 11.70 MgCha−1 and 43 species, the public parks in Kumasi have the potential to alleviate climate challenges and conserve biodiversity. The park species composition slightly deviates from the 10/20/30 benchmark stipulated for urban forests. Increasing park tree cover by restoring degraded sections of parks with tree species with high carbon densities, increasing the area and number of parks per city, adopting integrated park management approaches and plans backed by appropriate legislation and policies in cities in Africa could significantly enhance urban climate resilience, conserve biodiversity, and mediate mitigation and adaptation to warmer cities.

The data obtained from field-based forest inventories, mainly basal area and stem density, are relevant for the analysis of aboveground biomass and forest fragmentation. Due to its persistently flooded ground, fieldwork in mangrove forests is time-consuming and complicated. Since mangroves are sensitive to the effects of climate change, selecting a reliable field method is of utmost importance. To this end, we analyzed 4 mangrove classes: Rhizophora mangle (RM), Laguncularia racemosa (LR), Avicennia germinans (AG), and AG shrub. We georeferenced and counted all mangrove stems within four 0.04 ha (20 x 20 m square). We analyzed data from 3 circular area plots and the plotless point-centered quarter method (PCQM) based on the original square plots. Depending on the mangrove class, PCQM overestimated basal area by up to 34% and stem density by 21%. The 3 circular plot surveys underestimated basal area from -1% to -29% and stem density from -3 to -25%. Based on the results, we suggest using a circular plot of 0.04 ha (r = 11.28 m) in less dense forests (RM and AG) and a circular plot of 0.015 ha (r = 6.9 m) with forest densities greater than 3,500 stems/ha (LR and AG shrub). The advantages of using the circular plot approach over PCQM are that mangrove inventories can be quantified quickly and do not require a minimum number of sampling points. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the relationship between biodiversity and productivity can be advanced by improving metrics used to quantify biodiversity. Structural diversity, that is, variation of size and form of plant organs, is an emerging biodiversity metric. However, compared with the other biodiversity metrics, its relative importance in specific components of forest productivity, for example, recruitment of new individuals, biomass net change after accounting for mortality, is largely unknown, particularly across a large spatial scale with multiple influential gradients. To address the knowledge gap, we used USDA Forest Service Forest Inventory and Analysis (FIA) data across the southcentral USA from 2008 to 2017. We calculated forest biomass increments due to recruitment and growth and net change in biomass. Then, we quantified the effects of a range of abiotic and biotic variables on the biomass increments and net change. Our results showed that (1) Structural diversity was negatively associated with the two biomass increments and net change in biomass. The negative effects were supported by increased occurrences of insects and diseases with greater structural diversity. (2) Compared with species and functional diversity, structural diversity showed a better association with biomass increments and net change, suggested by its larger absolute values of standardized coefficients, and the effects of structural diversity were negative in contrast to species diversity. (3) The effects of structural diversity, stand age, and elevation differed between natural and planted forests that may stem from the differences in stand development and species composition between the two forest types. Together, structural diversity may represent an important dimension of biodiversity impacts on plant productivity, which could be related to the exacerbated disturbances with greater structural diversity. [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Invasive plant species (IPs) are widespread in forests and cause substantial environmental, economic and social impacts. They occupy native ecological niches, causing local extinctions to the detriment of native biodiversity and disrupting ecosystem services provision. How landscape characteristics may determine the success of IPs remains unclear and, more importantly, how land-use and land-cover changes may result in spatial shifts in the invasion risk. Furthermore, the study of how landscape factors may influence biological invasions has focused on particular species, but not the IPs' community. In this study, we identify and assess landscape variables that influence the presence and distribution of the IPs' community in temperate forests of a global biodiversity hotspot in south-central Chile. We fitted spatially explicit models, combining field-sampling information and landscape variables related to land-use/land-cover, topography, climate, soil characteristics and anthropogenic factors to explain and predict the presence and distribution of the IPs' community. From the whole sampling of plant species, we identified eight plant species classified as IPs: three trees and five shrubs. We used field data from 125 500 × 2 m-transects, in which we registered species richness, abundance and basal area of IPs' community. Distance to forest plantations was the landscape variable with the most substantial influence on IPs' presence and distribution. Richness, abundance and basal area of IPs' trees were higher at shorter distances from forest plantations. The basal area of IPs' trees was the best model explaining the relationship between IPs' community and landscape variables. All descriptors of the IPs' community showed similar spatial patterns: species richness, abundance and tree basal area are higher in more disturbed areas. Our findings contribute to increasing our understanding of the distribution patterns of IPs in forest landscapes. Our models can be suitable tools for designing strategies to prevent, mitigate or make integrated control of the impacts of invasive species in forest landscapes. [ABSTRACT FROM AUTHOR]

An estimated 3.4 million hectares of cocoa and 9.7 million hectares of cofee are cultivated, globally, under shade trees, i.e. in agroforestry systems. Shade canopies are characterized in terms of tree density (N, trees ha−1), tree basal area (G, m2 ha−1) and percent canopy cover (%Cov). N, G and %Cov are named shade canopy density variables (SCDV). The use of these SCDV has two important limitations: (1) diferent combinations of values of the three SCDV variables generate very diferent shade tree stands (hence very diferent shading levels), and (2) Additional factors modify shading under shade canopies with constant SCDV values. This article uses the software ShadeMotion (www. shademotion.net) to show how 24 diferent, simple, even-sized, mono-layered, Cordia alliodora shade canopies with constant N, G and %Cov display signifcantly diferent shade levels and temporal patterns of shading depending on tree stem and crown diameter ratios, tree height, spatial planting confgurations (square, random and alleys) and leaf fall patterns. A minimum set of variables capable of providing a more accurate description of the shading characteristics of a cocoa or cofee shade canopy is proposed. Our fndings can shed light on the current debate on the pros and cons of the defnitions of cocoa agroforestry used by chocolate and certifcation companies, governments, non-governmental organizations, and donors, especially in West and Central Africa. In this article, emphasis is given to cocoa, but the analysis, results and conclusions are equally applicable to coffee agroforestry systems. [ABSTRACT FROM AUTHOR]

Previous assessments of forest carbon sequestration mainly emphasized expanding forests and monitoring their growth over time. However, limited research has tackled enhancing carbon sequestration efficiency in existing forests, particularly by altering tree species demographics. Identifying species with significant contributions to carbon storage through growth and recruitment, as well as pinpointing regions and species with higher mortality rates (MRs), is essential for guiding forest restoration initiatives. This study utilized 1,248 permanent forest plots and 103,773 individual trees to examine the spatiotemporal demographic patterns of 20 dominant tree species from 1979 to 2017 in the Eastern Qinghai-Tibet Plateau and their impacts on forest live biomass carbon density. The findings indicate significant differences in the demographic rates of the 20 dominant tree species. The trees species composition and distribution in the study area were changed with the expansion and reduction of individual numbers of different trees species. For example, the expansion of Alnus cremastogyne, the shrink of Pinus yunnanensis and Pinus armandii populations. The growth rates (GRs) and recruitment rates (RRs) of Abies fabri, Acer miyabei, Betula albosinensis, Picea asperata, Juniperus squamata, Quercus semecarpifolia, and Salix takasagoalpina significantly increased live biomass carbon density. Conversely, increased MRs of Abies fabri, Cupressus funebris, Larix gmelinii, Picea asperata, Pinus armandii, Pinus densata, Pinus yunnanensis, and Salix takasagoalpina reduced forest live biomass carbon density. GRs and RRs offset MRs, resulting in an increase in carbon storage. Competition, which was estimated by the basal area per plot (BAplot), constrained the growth and recruitment and increased mortality of Pinaceae (Pinus armandii, Tsuga chinensis, Pinus yunnanensis, Pinus densata, Larix gmelinii, Picea likiangensis), particularly at low elevations and in the south of the study area. Interspecific variations in GRs, RRs, and MRs suggest selecting optimal species associations with high GRs and RRs, while thinning forests containing species with high MRs in suitable locations. The study enhances insights into the demographic rates of different species, establishes links between population dynamics and forest carbon sequestration, and further demonstrates the importance of adaptive scientific afforestation planning and forest management.

Background: The landscape of Harla-Ija Aneni Valley and Mountain Complex are inhabited by rich floristic diversity with endemism. However, the recurrent drought and over-exploitation of plant resources, coupled with increasing human population in the area, has been severely affecting the vegetation of these complex semi-arid ecosystems, which require research-based intervention. Objective: The objective of this study was to analyse the floristic composition, vegetation structure and diversity of Harla-Ija Aneni valley and mountain complex landscapes to support the on-going dry land restoration efforts undertaken in the study area. Material and Methods: A total of 58 quadrats each measuring 20 m x 20 m for trees, 5 m x 5 m for shrubs and woody climbers, and 1m x 1m for herbs and grasses were used to collect floristic data such as height and diameter at breast height (DBH) of woody species and type and number of plant species. Shannon-Weiner Diversity Index, richness, and evenness were used to analyse the vegetation data. Results: A total of 121 plant species belonging to 91 genera, and 48 families were identified, of which 10 species (8.3%) were endemic. Poaceae and Fabaceae were represented by higher number of species (11 species = 9.09%) each. Species richness, Shannon-Wiener Diversity Index (H'), and evenness values for the entire study area were 121, 3.12 and 0.38, respectively. Average basal area of woody species in the study area was 2.10 m2 ha-1, higher density at lower diameter class. The diameter and height class distribution of the woody species exhibited inverted J-shaped distributions, which indicate a continuous and good regeneration status. The three community types were: Acacia tortilis-Rhus natalensis, Ficus vasta-Acacia brevispica and Psychotria orophila-Canthium pseudosetiflorum. Conclusions and Implications: It is concluded that the study area harbours many native endemic plant species and taxonomic diversity. The results indicate that this unique landscape possesses ecologically and economically important plant species, which could be used as a provenance to establish semi-arid natural vegetation genetic resource centers in eastern Ethiopia. Therefore, the floristic diversity should be conserved to enhance ecosystem services. [ABSTRACT FROM AUTHOR]

Mangroves are one of the important coastal ecosystems in the world and Sundarbans is one of the major blocks of mangrove ecosystem. Indian covers 40% of the total Sundarbans mangrove area, while the remaining 60% is located in Bangladesh. For mangrove forest assessment and their sustainable management, there is need to estimate the forest biophysical/ structural attributes. The present study investigates some of the biophysical properties of mangrove vegetation of south-western part of Indian Sundarbans using L-band fully polarimetric Advanced Land Observation Satellite-2 (ALOS-2) Phased Array L-band Synthetic Aperture Radar-2 (PALSAR-2) data and field observations. The backscattering coefficients for all mangrove communities of the study area were computed where the cross polarizations (HV and VH) showed better potentiality for discrimination of the communities. Biophysical parameters of mangrove forest trees were modelled using multiple linear regressions. Synthetic Aperture Radar backscattering coefficients and some of the biophysical parameters were used as independent variables for basal area (BA) and aboveground biomass (AGB) estimations with the highest model R square value of 0.632 and 0.717, respectively. The validation root mean square error (RMSE) achieved in case of BA was 3.66 m2/ha, while the lowest validation RMSE attained for AGB was 46.10 Mg/ha. The methodology presented in the work may be applied for the entire Sundarbans (including both the remaining Indian part and the Bangladesh mangroves). [ABSTRACT FROM AUTHOR]

With current observations and future projections of more intense and frequent droughts in the tropics, understanding the impact that extensive dry periods may have on tree and ecosystem-level transpiration and concurrent carbon uptake has become increasingly important. Here, we investigate paired soil and tree water extraction dynamics in an old-growth upland forest in central Amazonia during the 2018 dry season. Tree water use was assessed via radial patterns of sap flow in eight dominant canopy trees, each a different species with a range in diameter, height, and wood density. Paired multi-sensor soil moisture probes used to quantify volumetric water content dynamics and soil water extraction within the upper 100 cm were installed adjacent to six of those trees. To link depth-specific water extraction patterns to root distribution, fine root biomass was assessed through the soil profile to 235 cm. To scale tree water use to the plot level (stand transpiration), basal area was measured for all trees within a 5 m radius around each soil moisture probe. The sensitivity of tree transpiration to reduced precipitation varied by tree, with some increasing and some decreasing in water use during the dry period. Tree-level water use scaled with sapwood area, from 11 to 190 L per day. Stand level water use, based on multiple plots encompassing sap flow and adjacent trees, varied from ∼1.7 to 3.3 mm per day, increasing linearly with plot basal area. Soil water extraction was dependent on root biomass, which was dense at the surface (i.e., 45% in the upper 5 cm) and declined dramatically with depth. As the dry season progressed and the upper soil dried, soil water extraction shifted to deeper levels and model projections suggest that much of the water used during the month-long dry-down could be extracted from the upper 2-3 m. Results indicate variation in rates of soil water extraction across the research area and, temporally, through the soil profile. These results provide key information on whole-tree contributions to transpiration by canopy trees as water availability changes. In addition, information on simultaneous stand level dynamics of soil water extraction that can inform mechanistic models that project tropical forest response to drought.

Abstract Dendrometer bands have been proposed as an accurate method for measuring tree growth. However, the constrained observation window and the material used in them hamper long-term tree growth monitoring. This study devised a dendrometer band made from stainless steel and primarily extended the extension length of the band spring to yield ample space to monitor diameter increments long-term. A total of more than 500 individual trees, including both coniferous and broadleaf trees, were examined. We compared the dendrometer band’s long-term performance with diameter tape for 5- and 10-year measurements. The results showed that the measurements of the two methods were highly correlated (R > 0.89) in both measuring periods. Differences between the two measurements for individual trees were typically less than 5 mm, and the mean differences at a stand level were less than 2 mm. These consistent observations suggested that the dendrometer band measurements were reliable for long-term measurement. Using the dendrometer bands, we further demonstrated the annual tree growths of diameter at breast height (DBH) and basal area (BA) for ten years of measurements. The size-dependent relationships between DBH/BA growth and initial DBH were also presented. Owing to their simple installation, low cost, and reliable measurement, these dendrometer bands would be helpful in forestry and forest ecology research.

The data obtained from field-based forest inventories, mainly basal area and stem density, are relevant for the analysis of aboveground biomass and forest fragmentation. Due to its persistently flooded ground, fieldwork in mangrove forests is time-consuming and complicated. Since mangroves are sensitive to the effects of climate change, selecting a reliable field method is of utmost importance. To this end, we analyzed 4 mangrove classes: Rhizophora mangle (RM), Laguncularia racemosa (LR), Avicennia germinans (AG), and AG shrub. We georeferenced and counted all mangrove stems within four 0.04 ha (20 × 20 m square). We analyzed data from 3 circular area plots and the plotless point-centered quarter method (PCQM) based on the original square plots. Depending on the mangrove class, PCQM overestimated basal area by up to 34% and stem density by 21%. The 3 circular plot surveys underestimated basal area from –1% to –29% and stem density from –3 to –25%. Based on the results, we suggest using a circular plot of 0.04 ha (r = 11.28 m) in less dense forests (RM and AG) and a circular plot of 0.015 ha (r = 6.9 m) with forest densities greater than 3,500 stems/ha (LR and AG shrub). The advantages of using the circular plot approach over PCQM are that mangrove inventories can be quantified quickly and do not require a minimum number of sampling points.

Context: Native early-successional plants and invasive exotic plants often colonize the same disturbed space and have similar functions, making interactions likely. Knowing whether these interactions are facilitative or competitive across different scales will help determine the influence of such species across a forested landscape. Objective: We evaluated the impacts of an early-successional, nitrogen-fixing native (facilitator), Robinia pseudoacacia, and an allelopathic invasive (inhibitor), Ailanthus altissima, on regeneration, basal area, and diversity of forests at local and regional scales. Methods: Locally, all woody stems were mapped in three post-disturbance, mid-successional plots at two sites in Virginia, US. Plots contained A. altissima or R. pseudoacacia or both. Target species were evaluated regionally and spatially using USDA Forest Inventory and Analysis data across 31 eastern states, US. Results: Spatial contagion was found between A. altissima and R. pseudoacacia at both scales. Regeneration of A. altissima was much greater than that of R. pseudoacacia but native tree regeneration was negatively associated with both target species. Regionally, R. pseudoacacia was more common than A. altissima. At both scales, A. altissima was more likely to form dense stands than R. pseudoacacia. Locally, plot types did not differ in tree diversity. Regionally, R. pseudoacacia plots had higher tree diversity than plots without either target species. Conclusions: Robinia pseudoacacia and A. altissima's positive association is maintained into mid- and late-successional forests and A. altissima inhibits regeneration locally and regionally. Robinia pseudoacacia shows a positive effect on diversity but only when compared with mature forests at the regional scale. [ABSTRACT FROM AUTHOR]

As forest managers increasingly seek to implement partial-harvest silviculture systems in complex forests, more data are required on the potential development of the residual stand following treatment. In this study, we present 25-year data from a long-term silvicultural study of tree- and stand-level responses to differing levels of basal area following partial harvest in a complex spruce–fir forest in central British Columbia, Canada. Reducing stand basal area elicited stronger basal area increment response in fir than spruce; however, spruce productivity was overall higher than fir across all treatments. Smaller trees increased their size proportionally more than larger trees, and thinning resulted in increased recruitment of smaller trees into larger diameter classes. At the stand-level, basal area reductions to well below 20 m2/ha resulted in higher volume and basal area growth over the length of this study, and suggest that optimum stand-level growth may be achieved at lower basal areas than suggested in prior literature. We also found a positive relationship between stand-level residual basal area and mortality. In central British Columbia, stand structure, species composition, and growth rates in complex spruce–fir forests can be maintained through partial-harvest silviculture treatments. [ABSTRACT FROM AUTHOR]

In Brazil, logging in the Seasonally Dry Tropical Forest (SDTF) under management plans that include clear-cutting has increased in recent decades, and the structure, composition, diversity and functioning of the forest likely must have been affected. The aim of this study was to understand the growth dynamics of shrub–tree biomass (STB), species richness and vegetation structure as a function of regeneration time after clear-cutting (treatments), taking the Legal Reserve (40 years of regeneration) as reference. The study was carried out in 2018 at the Ramalhete Settlement, General Sampaio, in the state of Ceará. All plants with a circumference at breast height (CBH) ≥ 6 cm were identified and the CBH was measured across 42 sample plots (20.0 m × 20.0 m), using seven plots per treatment (3, 5, 8, 11 and 15 years after clear-cutting, and the Legal Reserve, 40 years of regeneration). The following were determined: STB (total and by species), density and basal area (by ecological group and diameter class), basal area (species of higher added value), diversity (Hill numbers), and the importance value index (IVI). It was found that during the early years (up to at least 11 years), many important forest characteristics related to the composition of the ecological groups and vegetation structure were strongly affected, and major impacts can be seen, the effects of which, however, decreased over time of regeneration, having almost no effect after 15 years. After 15 years following clear-cutting, the SDTF presented accumulated STB, species richness and structure similar to the area undergoing regeneration for 40 years. However, the small number of indicator species of more-preserved areas (even at T15 and T40) points out that management needs to be improved. However, promoting species of greater added value and determining whether the forest recovers its structure and diversity after successive cutting cycles also still need to be addressed. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate the influence of thinning on natural Brutian pine (Pinus brutia Ten.) stands in Isparta/Sütçüler Forestry Management Directorate. The effect of the four-year results of thinning on the growth characteristics of Brutian pine stands was evaluated at two different levels applied in two different areas at similar elevation. Moderate thinning was performed in area I, and heavy thinning was performed in area II. Thinning applied in Brutian pine stands in both areas had an effect on mean diameter at breast height, tree height, tree stability and total basal area. Tree stability, diameter and height growth of trees increased with the thinnings applied. At the end of four years, no significant difference was determined between the areas where thinnings was applied and the control areas in terms of the total volume per hectare in both areas. As a result, heavy thinning may be preferred as the first thinning in areas where regular maintenance is applied in natural Brutian pine stands. In areas where regular maintenance is not applied, moderate thinning can be applied considering the development of the stand.

Gathering accurate data on forest resources is one of the most important steps in sustainable planning for these forests. Remote sensing techniques have been widely used in forest management by predicting various forest parameters such as volume, tree density and basal area. This research was conducted in Kalala Forest in northern Iran, and field data were collected by cluster sampling method. 105 samples were inventoried with an area of 400 square meters per sample. At the level of each sample, diameter at breast height and tree height were measured. The volume, tree density, and basal area per hectare of the studied samples were calculated. The values of vegetation indices at the studied sample sites were extracted through the Sentinel-2 satellite image. The relationship between the studied parameters and vegetation indices was modeled through the use of the Random Forest algorithm. This research aims to investigate the ability of the Sentinel-2 satellite to estimate volume, basal area and tree density in the study area using the Random Forest algorithm. Volume modeling results showed that the coefficient of determination (R2) was equal to 0.88, and the percentage root mean square error (%RMSE) was equal to 21.01%. While the results of basal area modeling showed that the coefficient of determination was 0.88, and the percentage of root mean square error was 20.14%. The results of tree density modeling showed that the coefficient of determination was 0.89, and the percentage of root mean square error was 19.22%. The results also showed that the use of the Sentinel-2 satellite and the Random Forest algorithm in modeling gave positive and acceptable results.

IntroductionPlant diversity and soil chemical properties are important factors affecting the plant growth. We sought to compare the explanatory rates of diversity and soil chemical properties in explaining the variation of basal area in karst forests, and also sought to compare the relative importance of the niche complementarity and mass ratio hypotheses.MethodsOn the basis of linear regression and structural equation modelling, we examined the correlation between the basal area of plant communities and species diversity, functional diversity, phylogenetic diversity, the community-weighted mean (CWM) of traits, and soil chemical properties, using data obtained from 35 monitoring plots in southwest China.ResultsSpecies, functional, and phylogenetic diversities were all significantly correlated with the basal area of the plant community, among the indices of which, Faith’s phylogenetic diversity was found to have the greatest explanatory power for basal area. These plant diversity indices can better explain the variation in basal area than the CWM of traits, suggesting the niche complementarity hypothesis is more applicable than the mass ratio hypothesis. Moreover, soil chemical properties also have an equal important impact. Different chemical properties were found to show significant positive correlations with basal area, and their total effects on basal area were shown to be greater than the CWM of traits.DiscussionAttention should be paid to diversity and soil chemical properties. This study provides theoretical guidance for understanding biodiversity maintenance mechanisms and protecting karst forests.

Climate change has resulted in an increase in drought severity in the species-rich tropical and subtropical forests of southern China. Exploring the spatiotemporal relationship between drought-tolerance trait and tree abundance provides a means to elucidate the impact of droughts on community assembly and dynamics. In this study, we measured the leaf turgor loss point (πtlp) for 399 tree species from three tropical forest plots and three subtropical forest plots. The plot area was 1 ha and tree abundance was calculated as total basal area per hectare according to the nearest community census data. The first aim of this study was to explore πtlp abundance relationships in the six plots across a range of precipitation seasonality. Additionally, three of the six plots (two tropical forests and one subtropical forest) had consecutive community censuses data (12–22 years) and the mortality ratios and abundance year slope of tree species were analyzed. The second aim was to examine whether πtlp is a predictor of tree mortality and abundance changes. Our results showed that tree species with lower (more negative) πtlp were more abundant in the tropical forests with relative high seasonality. However, πtlp was not related to tree abundance in the subtropical forests with low seasonality. Moreover, πtlp was not a good predictor of tree mortality and abundance changes in both humid and dry forests. This study reveals the restricted role of πtlp in predicting the response of forests to increasing droughts under climate change. [ABSTRACT FROM AUTHOR]

Dendrometer bands have been proposed as an accurate method for measuring tree growth. However, the constrained observation window and the material used in them hamper long-term tree growth monitoring. This study devised a dendrometer band made from stainless steel and primarily extended the extension length of the band spring to yield ample space to monitor diameter increments long-term. A total of more than 500 individual trees, including both coniferous and broadleaf trees, were examined. We compared the dendrometer band's long-term performance with diameter tape for 5- and 10-year measurements. The results showed that the measurements of the two methods were highly correlated (R > 0.89) in both measuring periods. Differences between the two measurements for individual trees were typically less than 5 mm, and the mean differences at a stand level were less than 2 mm. These consistent observations suggested that the dendrometer band measurements were reliable for long-term measurement. Using the dendrometer bands, we further demonstrated the annual tree growths of diameter at breast height (DBH) and basal area (BA) for ten years of measurements. The size-dependent relationships between DBH/BA growth and initial DBH were also presented. Owing to their simple installation, low cost, and reliable measurement, these dendrometer bands would be helpful in forestry and forest ecology research. [ABSTRACT FROM AUTHOR]

Population growth as well as increasing migration to cities in recent decades has led to increased population density as well as the area of large cities. Noise pollution is one of the environmental problems in big cities, which endangers human health in various psychological and physical aspects. However, this type of pollution has received less attention than other pollutants. This research was conducted with the aim of investigating and modeling the effect of tree species on road noise pollution. The present study was carried out in Noor Forest Park in which 6 stations including 5 different tree stands and one control area were selected for the study. Measurement of noise pollution was performed in each station with 5 replications at distance intervals of 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 meters from the sound source with two noise frequencies of 250 and 500 Hz in two seasons of winter and summer. The studied characteristics include tree species, distance from the sound source, growing season (summer and winter), and stand attributes including mean diameter at breast height, the average height of the stand, basal area per hectare, total basal area of trees from the sound source to the location of receiver. Based on the model selection criteria, the linear model showed the best fit for modeling the effect of environmental factors on the amount of noise pollution. Based on the results, the effect of distance, species, season, intensity of noise pollution and total basal area of trees on the amount of noise pollution were significant. The distance from the source of noise pollution and the total basal area of the trees showed an inverse relationship with the amount of noise pollution. The highest noise pollution was related to the control areas without trees and the lowest was related to the Gleditsia-Alnus mixed stands. It can be concluded that noise pollution can be reduced more effectively with optimal design through afforestation of mixed stands so that the species cover different floors, especially at a height close to the ground. [ABSTRACT FROM AUTHOR]

A significant portion of the harvested land base in western Canada is becoming old enough or entering a phase where thinning is a legitimate forest management option. A comprehensive review of the existing knowledge of commercial thinning (CT) treatments applied to pine and spruce-dominated stands in Alberta was conducted, with particular regard to the intensity, timing of interventions, method, and impacts on crop tree growth responses. Although the geographical focus of this review is Alberta, information on this topic is more complete in other areas of North America and Europe, where there is a long history of density management. In areas of eastern North America, our review revealed that CT from below, with tree removal levels from 27 to 43% of the basal area, could increase total merchantable wood produced from 11 to 60 m3 ha−1 over a rotation, depending on stand age and intensity of thinning. For Alberta conditions, and considering the risks, we conclude that commercial thinning basal area removal should be in the range of 25 to 40%, depending on a variety of factors such as species, wind firmness, and insect or disease incidence and risk. Thinning too aggressively and/or too late will increase the blowdown risk but the literature is fairly consistent in suggesting that live crown ratios should be >40% to maximize the chance of growth response and minimize the blowdown risk. In cases where stands are also threatened by stressors such as drought, wind, and insect or disease outbreaks, CT treatments likely offer the potential at limiting the overall risk, but localized knowledge and experience are critical. It is intended that the information presented may support ongoing and future research trials and growth and yield (G&Y) model development about potential CT treatments to apply and the likely results of practical application to commercial forestry. [ABSTRACT FROM AUTHOR]

Temperature rise and more severe and frequent droughts will alter forest transpiration, thereby affecting the global water cycle. Yet, tree responses to increased atmospheric vapour pressure deficit (VPD) and reduced soil water content (SWC) are not fully understood due to long‐term tree adjustments to local environmental conditions that modify transpiration responses to short‐term VPD and SWC changes.We analysed sap flux density (SFD) of Fagus sylvatica, Picea abies, Pinus sylvestris and Quercus ilex from 25 sites across Europe to understand how daily variation in SWC affects the sensitivity of SFD to VPD (βVPD) and the maximum SFD (S95). Furthermore, we tested whether long‐term adjustments to site climatic conditions and stand characteristics affect βVPD and S95.The studied species showed contrasting βVPD and S95 with the largest values in F. sylvatica, followed by Q. ilex, which surpassed the two conifers that showed low βVPD and low S95. We observed that βVPD and S95 dropped during days of low SWC in F. sylvatica, P. sylvestris and Q. ilex, but not in P. abies. Both βVPD and S95 were driven by tree height, and the temperature and precipitation at the sites. However, stand basal area was the most important driver of βVPD and S95, explaining 30% of their total variance.Synthesis and applications: A future warmer and drier climate will restrict tree transpiration and thereby heavily affect the soil–plant‐atmosphere coupling. However, the effect of basal area, being the largest driver of tree transpiration sensitivity to vapour pressure deficit across a broad range of conditions, provides the opportunity to pre‐adapt European forests to future climate conditions. While stand thinning can increase the soil water availability for remaining trees, it also increases transpiration sensitivity to high air temperatures and may thereby amplify tree vulnerability to heat and drought. [ABSTRACT FROM AUTHOR]

Urban parks are an important part of the city's green infrastructure and serve as an indicator for the city's natural environment. Six urban parks in Faisalabad were evaluated, split into two categories: Old parks (OP) and New parks (NP). A thorough census of tree populations was conducted in specified urban parks, and many parameters were studied. The composition of trees, species richness, and distribution of native and exotic trees were evaluated among two types of parks. Tree stem count was used to calculate the diversity benchmark (10/20/30) for tree inventories in selected urban parks. The major objective of the study was to determine the difference in species richness and diversity indices of selected urban parks in both categories. Evaluation of the plantation of Urban parks on the basis of the proposed benchmark (10/20/30) was also the key objective of the present study. The results revealed that 2978 trees from 52 species, 45 genera, and 22 families had been counted, with 2004 trees in the OP and 794 in the NP. A few common species hold the majority of the distribution. OP have higher share of native trees (67.07%) while NP have higher share of exotic trees (59.32%). The dominance of exotic tree species in NP depicted that change in time has significantly affected the plantation pattern of urban parks in Faisalabad. OP had higher tree species richness (47) as compared to NP (36). The dominance of exotic species in new parks is the major cause of low tree diversity. Results of the tested benchmark indicated that the plantation of selected urban parks approximately failed to achieve the proposed diversity benchmark. In urban parks, more attention should be paid to the plantation design and species selection. The pressing need of the hour is to have a tree mix that promotes biodiversity while also maximizing ecological services. [ABSTRACT FROM AUTHOR]

In this study, the effect of pine mistletoe (Viscum album subsp. austriacum) on basal area increment of Crimean pine and Scots pine was investigated. Dendrochronological data were collected from 223 (71 uninfected and 152 infected) Crimean pines and 195 (77 uninfected and 118 infected) Scots pines located in Kastamonu province of Turkey in 2014. Infected sample trees were classified as light, moderate or severe infection levels. Growth trends and basal area increment loses were compared between uninfected and infected trees for the periods of the last 10, 20 and 30 years. In addition, infection status of forest stands was investigated using temporary sample plots; 27 plots in Crimean pine stands and 26 plots in Scots pine. Results demonstrated that basal area increments were negatively affected by pine mistletoe for both species. Mean basal area increment losses of infected trees for the last decade were determined as 24% for Scots pine and 26% for Crimean pine. Basal area increment losses varied by infection levels (light, moderate and severe) as follows: 25%, 20% and 28% for Scots pines and 20%, 32% and 9% for Crimean pines. Scots pine stands were more severely infected by pine mistletoe than Crimean pine stands. There were negative correlations between number of infected trees and stand density for both species, while positive correlation was detected between the number of infected trees and mean diameter for Scots pine. The results of this study indicate that the pine mistletoe infection has negative effect on radial growth of Scots pine and Crimean pine trees. The results can be an important contribution to the forest management and protection activities in mistletoe‐infected stands. [ABSTRACT FROM AUTHOR]

Sacred forests are of immense value for their ecosystem functions. Traditional indigenous conservation practices have helped to maintain biological diversity over centuries and have resulted in the preservation of some of the best patches of natural vegetation. Species that are endemic and restricted only to certain ecosystems find refuge in the micro-climatic conditions of sacred groves and many rare species are found here. Here, we compared species composition, floristic structure, diversity, and occurrence of amphibians, insects (odonatan) and birds in ten sacred swamps and ten non-sacred swamps in the central Western Ghats region, India. The sites were chosen based on similarities in distance from roads, village settlements, or commercial orchards and size. In the sacred swamps, 122 plant species from 99 genera and 58 families occur compared to 83 species from 72 genera and 47 families in the non-sacred swamps. Tree stem density was 277 individuals/ha in sacred swamps against 158.4 in nonsacred swamps. Average basal area was 47.57 m2/ha in sacred swamps and only 14.60 m2/ha in non-sacred swamps. Regeneration of swampy species is much better in sacred swamps showing a positively skewed distribution of individuals over all classes. Sacred swamps have a higher number of endemic species (28%) when compared to non-sacred swamps. There exist significant differences in the Shannon index of species diversity of amphibians and birds between sacred and to non-sacred swamps. We conclude that the traditional belief system of treating the swamps as sacred has helped to protect these ecologically important forests. Sacred forests are of immense value for their ecosystem functions. Traditional indigenous conservation practices have helped to maintain biological diversity over centuries and have resulted in the preservation of some of the best patches of natural vegetation. [ABSTRACT FROM AUTHOR]

Restoring wetlands is expensive, and methods for evaluating restoration condition are needed. This study developed chronosequences for use in ecological assessments (EAs) of restoration projects for Carolina Bay wetlands (CBWs) in the Southeastern US that were previously used for agriculture. An empirical method was also developed to estimate saturation levels to be used with the chronosequences. Data were collected from nine restored CBWs whose restoration ages ranged from 0 to 23 years. Plots were sorted into four Hydrologic Groups: 0–13 (Group 1), 14–50 (Group 2), 51–100 (Group 3), and 101+ (Group 4) consecutive days of saturation within 30 cm of the soil surface during the growing season. Litter thickness, tree basal area, and potential tree height were measured within a variable radius plot using a 10-factor prism across all Hydrologic Groups. Litter thickness and tree height reached an equilibrium at 15 years since restoration once crown closure occurred at the sites. In Groups 1 and 2, tree basal area reached an equilibrium at 15 years, and in Groups 3 and 4 it increased linearly to 23 and 21 years. Regression equations were developed (R2 = 0.57–0.73) to estimate saturation duration based on hydrology indicators, litter thickness, potential tree height, and soil type. These results showed that chronosequences and saturation duration would be useful for proposing performance standards in restored CBWs at time periods ranging from 5 to 23 years.

Forest management depends on forest condition data and the ability to quantify the impacts of management activities to make informed decisions. Spatially quantifying water yield (WY) from forests across large landscapes enables managers to consider potential WY changes when designing forest management plans. Current forest water yield datasets are either spatially coarse or too restricted to specific sites with in situ monitoring to support some project-level forest management decisions. In this study, we spatially apply a stand-level southern pine WY model over a forested landscape in the Florida panhandle. We informed the WY model with pine leaf area index inputs created from lidar remote sensing and field data, a spatial and temporal aridity index from PRISM and MODIS data, and a custom depth to groundwater dataset. Baseline WY conditions for the study area were created using the Esri and Python tools we developed to automate the WY workflow. Several timber thinning scenarios were then used to quantify water yield increases from forest management activities. The results of this methodology are detailed (10 m spatial resolution) forest WY raster datasets that are currently being integrated with other spatial datasets to inform forest management decisions. [ABSTRACT FROM AUTHOR]

Tropical forests undergoing restoration can present high biomass accumulation rates, especially in the first 20 years. However, native species reforestations often present a bias toward fast growth, low wood density, and small maximum adult size species, contrasting with most mature forest species. Since tree species adult size and wood density are key traits that influence biomass accumulation, these induce uncertainty regarding carbon uptake capabilities of restoration projects in the long term. We compared the density of individuals (DI), basal area (BA), aboveground biomass (AGB), and weighted average wood density (WDW) in 13–14‐year‐old restoration sites and in mature seasonal Atlantic Forest fragments. We also assessed the contribution of pioneer and non‐pioneer and planted and non‐planted species on these variables at restoration sites. Furthermore, we investigated the DI and WDW for saplings and seedlings, in order to foresee changes in forest structure that may result from natural recruitment of dense‐wood mature species. The BA and WDW at restoration sites were similar to forest fragments, except for large trees (DBH ≥50 cm). Restoration sites recovered AGB to the level of forest fragments only for the smaller size class (DBH 5–19.9 cm). Planted pioneer and non‐pioneer species accumulated the greatest AGB (93%), BA (94%), and DI (90%) at restoration sites. The DI of non‐planted non‐pioneer species with higher WDW increased among saplings and seedlings at restoration sites. The presence of species with a larger adult size and higher WD may indicate long‐term increase in biomass accumulation at restoration sites. [ABSTRACT FROM AUTHOR]

Broussonetia papyrifera has been identified as one of the top invasive species in African tropical forests, with potentially devastating impacts on conservation and timber production of forests. This study aimed at understanding the influence of B. papyrifera invasion on selected native timber producing species in afrotropical forests. Employing a complete randomized block design, a total of 40 plots (30 × 30 m each) which were equally distributed between invaded and uninvaded sites with similar habitat conditions, were surveyed for seedlings, saplings and trees of selected native timber species in Mabira Forest Reserve, Uganda. The abundance, basal area and population structure of these timber species were compared between sites invaded and uninvaded by B. papyrifera. The study revealed that the effects of B. papyrifera invasion vary depending on the growth stage and species studied. Overall, B. papyrifera invasion significantly reduced the abundance and basal area of selected native timber species. B. papyrifera invasion suppressed tree regeneration in some of the selected native timber species as shown by individuals missing in large size classes. Our results demonstrate that if the spread of B. papyrifera is not abated, it would lower the timber production potential of tropical forests. Therefore, we call for interventions to prevent the spread of B. papyrifera to uninvaded parts of the forests and halt its multiplication in invaded sites so as to enhance the regeneration and growth of timber species. [ABSTRACT FROM AUTHOR]

Volume increment is one of the main concerns in forestry practice. The aim of our study was to examine the impact of factors influencing the periodic annual increment of oak. To meet our objective, we used measurement data from the national forest inventory in Poland from 2005 to 2019 for oak-dominated stands. Our study used data of 1464 sample plots with dominant oak species (Quercus sessilis Ehrh. ex Schur and Quercus robur L.) measured within the national forest inventory in Poland. We developed models explaining the dependence of the periodic annual volume increment on stand characteristics using the generalized additive model. The generalized additive model allows us to analyze each variable's effect on the dependent variable, with all other variables fixed. We documented the effect of age, height, basal area, and relative spacing index (RSI) on the periodic annual volume increment (PAIv) of oaks in Poland. The PAIv of oaks decreased gradually as the tree aged. The dependence of the PAIv on stand density was shown through its relationship with the basal area and RSI. The developed model explained about 64.6% of the periodic annual volume increment variance. [ABSTRACT FROM AUTHOR]

This paper describes the use of remotely sensed data to measure vegetation variables such as basal area, biomass and stand volume. The objective of this research was developed regression models to estimate basal area (BA), aboveground biomass (AGB), and stand volume (SV) using Landsat-based vegetation indices. The examined vegetation indices were SAVI, MSAVI, EVI, NBR, NBR2 and NDMI. Regression models were developed based on least-squared method using several forms of equation, i.e., linear, exponential, power, logarithm and polynomial. Among those models, it was recognized that the best fit of model was obtained from the exponential model, log (y) = ax + b for estimating BA, AGB & SV. The MSAVI had been identified as the most accurate independent variable to estimates basal area with R² of 0.70 and average verification values of 16.39% (4%-32.66%); while the EVI become the best independent variable for estimating aboveground biomass (AGB) with R2 of 0.72 and average of verification values of 18,10% (9%-28.01%); and the NDMI was recognized to be the best independent variable to estimate stand volume with R2 of 0.69 and average of verification values of 24.37% (-15%-38.11%).

Hair lichens in the genera Alectoria and Bryoria dominate old-growth circumboreal coniferous forests and have important ecosystem functions, particularly for reindeer and caribou. These lichens are sensitive to changes in climate and are unable to maintain a high standing crop in industrial forestry based on clear-cutting, highlighting the need of management models based on continuous cover forestry. We examined how dry mass (DM) growth and CO 2 exchange in hair lichens depended on the balance between growth (carbon gain from photosynthesis) and losses (both carbon loss from respiration and mass loss from fragmentation). Partial cutting trials were conducted in a Picea abies -dominated forest by three levels of basal area (BA) removal (0 %; 33 %; 67 %), with five 80 m × 80 m plots per level. We compared two species with similar functional traits but with different cortical pigments, the pale Alectoria sarmentosa and the dark Bryoria fremontii. Lichens were transplanted within the lower canopy using net cages over a 1-year period to evaluate net growth, loss by thallus fragmentation and gross growth. Canopy openness and transmitted radiation during the growing season were estimated from hemispherical photographs. Canopy temperature, relative humidity, and photosynthetic photon flux density were monitored, with microclimate data subsequently used to model net CO 2 exchange using previously published response matrices describing net photosynthetic and respiratory activity. Net DM growth of A. sarmentosa was higher than in B. fremontii , and increased with level of BA removal, being twice as high in the 67 % BA removal as in the control. In contrast, B. fremontii responded weakly to partial cutting due to high rates of thallus fragmentation. However, gross growth of both species increased with canopy openness and transmitted radiation. The modelled net assimilation showed large seasonal variation, with the largest difference among levels of BA removal in autumn. The estimated DM growth agreed well with observed gross growth in A. sarmentosa but was underestimated in B. fremontii. Modelling of CO 2 exchange can provide a mechanistic understanding of how hair lichens respond to partial cutting and climate change. The response of hair lichens to microclimate in partial cuts depends on the trade-off between growth and losses. Results suggest that the faster lichen growth on residual trees in the one-third removal partial cuts compensated to a significant degree for the loss of lichen mass by the removal of host trees. [Display omitted] • Net growth of Alectoria was doubled in plots with 67 % basal area removal. • Bryoria responded weakly to partial cutting due to high thallus fragmentation. • Gross growth of both species increased with canopy openness and transmitted light. • Gross growth of hair lichens can be predicted from microclimate and CO 2 gas exchange. • Partial cutting has large potential to improve growth of hair lichens on residual trees. [ABSTRACT FROM AUTHOR]

In Brazil, logging in the Seasonally Dry Tropical Forest (SDTF) under management plans that include clear-cutting has increased in recent decades, and the structure, composition, diversity and functioning of the forest likely must have been affected. The aim of this study was to understand the growth dynamics of shrub–tree biomass (STB), species richness and vegetation structure as a function of regeneration time after clear-cutting (treatments), taking the Legal Reserve (40 years of regeneration) as reference. The study was carried out in 2018 at the Ramalhete Settlement, General Sampaio, in the state of Ceará. All plants with a circumference at breast height (CBH) ≥ 6 cm were identified and the CBH was measured across 42 sample plots (20.0 m × 20.0 m), using seven plots per treatment (3, 5, 8, 11 and 15 years after clear-cutting, and the Legal Reserve, 40 years of regeneration). The following were determined: STB (total and by species), density and basal area (by ecological group and diameter class), basal area (species of higher added value), diversity (Hill numbers), and the importance value index (IVI). It was found that during the early years (up to at least 11 years), many important forest characteristics related to the composition of the ecological groups and vegetation structure were strongly affected, and major impacts can be seen, the effects of which, however, decreased over time of regeneration, having almost no effect after 15 years. After 15 years following clear-cutting, the SDTF presented accumulated STB, species richness and structure similar to the area undergoing regeneration for 40 years. However, the small number of indicator species of more-preserved areas (even at T15 and T40) points out that management needs to be improved. However, promoting species of greater added value and determining whether the forest recovers its structure and diversity after successive cutting cycles also still need to be addressed.

Mining companies in Ghana have been encouraged by law and policy to reclaim degraded mined sites using native tree species. The study assessed stand structure, compositional dynamics, conservation and economic value of restored species after 20 years of reclamation. Eighty seedlings each of Amphimas ptericarpoides and Macaranga barteri were planted on the first reclaimed site (stand I); 160 seedlings each of Macaranga barteri and Amphimas ptericarpoides on the second (stand II) and third (stand III) reclaimed sites respectively. Each reclaimed site (1000 m2) was inventoried and sampled using 400 quadrats (25 m × 25 m). In all, 123 ‘restored‘ species in 55 families (stand I), 103 species in 52 families (stand II) and 96 species in 49 families (stand III) were identified. Species composition of the reclaimed sites were moderately similar to the old-growth forest remnant. Pioneer species, zoophilous and zoochorous species were dominant in all the reclaimed sites. One hundred and twenty-four adult (DBH > 5 cm) tree species (stand I), 105 (stand II) and 128 (stand III) were obtained. The tree stand structure of the Amphimas reclaimed site had the highest basal area of 13.75 m2/ha and most of the adult tree species in all the reclaimed sites were in the lower diameter class (5 cm ≥ DBH < 20 cm). The Genetic Heat Index and Economic Index of trees-only were significantly (p < 0.05) higher in the Amphimas -Macaranga site. The mixed tree species of the Amphimas – Macaranga reclaimed site seem to perform better as almost all measured parameters were dominant on this site. The two tree species used have high potential for restoration of native species. Later studies will further establish the suitability of the two native tree species for reclamation in the study area.

The TreeMap 2016 dataset provides detailed spatial information on forest characteristics including number of live and dead trees, biomass, and carbon across the entire forested extent of the continental United States at 30 × 30m resolution, enabling analyses at finer scales where forest inventory is inadequate. We used a random forests machine learning algorithm to assign the most similar Forest Inventory Analysis (FIA) plot to each pixel of gridded LANDFIRE input data. The TreeMap 2016 methodology includes disturbance as a response variable, resulting in increased accuracy in mapping disturbed areas. Within-class accuracy was over 90% for forest cover, height, vegetation group, and disturbance code when compared to LANDFIRE maps. At least one pixel within the radius of validation plots matched the class of predicted values in 57.5% of cases for forest cover, 80.0% for height, 80.0% for tree species with highest basal area, and 87.4% for disturbance. A new feature of the dataset is that it includes linkages to select FIA data in an attribute table included with the TreeMap raster, allowing users to map summaries of 21 variables in a GIS. TreeMap estimates compared favorably with those from FIA at the state level for number of live and dead trees and carbon stored in live and dead trees. Study Implications: TreeMap 2016 provides a 30 × 30 m resolution gridded map of the forests of the continental United States. Attributes of each grid cell include a suite of forest characteristics including biomass, carbon, forest type, and number of live and dead trees. Users can readily produce maps and summaries of these characteristics in a GIS. The TreeMap also includes a database containing, for each pixel, a list of trees with the species, diameter, and height of each tree. TreeMap is being used in the private sector for carbon estimation and by land managers in the National Forest system to investigate questions pertaining to fuel treatments and forest productivity as well as Forest Plan revisions. [ABSTRACT FROM AUTHOR]

Frequent (≤3 y) prescribed burn has been conducted in the Escambia Experimental Forest in southern Alabama, USA, since 2001.The change in the density of new germinants (≤1 y) and older seedlings and saplings (>1 y) of longleaf pine (Pinus palustris Mill.) from stands of varying conditions was quantified using the locally estimated scatterplot smoothing and spatial statistical methods. A relatively longer fire interval or time since last fire (TSLF) > 600 days favored the recruitment of young seedlings. However, a short fire return interval or TSLF≤ 600 days promoted the recruitment of older seedlings and saplings. Large basal area (BA) and site index (SI) tended to diminish natural regeneration, whereas large quadratic mean diameter (QMD) and age were facilitative. The interactive effect of these factors indicated that a ratio of TSLF/BA of 60 to 120 and QMD/SI of 1.8 to 2.2 would maximize the recruitment of young seedlings. The recruitment of older seedlings and saplings increased linearly with QMD/SI but had no relationship with TSLF/BA. Recruitment was largely absent when QMD/SI was <2.0. As a result, we recommend that QMD/SI be no greater than 2.0 and TSLF/BA range from 60 to 120 to regenerate longleaf pine naturally. [ABSTRACT FROM AUTHOR]

Bark stripping by red deer (Cervus elaphus L.) is one of the most acute instances of damage wrought by these animals in a forest. Because of its location, bark stripping causes damage to the thickest and most valuable part of the tree trunk, which lowers the quality of the wood due to technical flaws. The research was conducted in 25 sampling sites of pine stands aged 35 years in a mixed, fresh forest habitat in south-western Poland. The study was aimed at assessing the influence of bark damage by deer on biometric parameters of pine stands (Pinus sylvestris L.). The assessment involved the diameter at breast height, height, basal area and volume of the tree stands. The results revealed a strong deer-specific pressure on the analysed pine stands. The share of bark stripped trees ranged from 65% to 96%. The number of bark damage instances (NBDI) on a given tree was found to significantly affect its diameter at breast height. The strip-damaged trees had breast height diameters lower by 23% on average, and their mean height was lower by 8.7% as compared with the trees without damage. The mean reduction in basal area increments ( G 1.3 ) of the trees was identified at 39%. In a similar way to the diameter at breast height and the basal area, the losses in tree stand volume growth caused by deer stripping were significant and oscillated at 41%. [ABSTRACT FROM AUTHOR]

Background: Heteroflorum (Fabaceae) is a monospecific genus endemic to western Mexico. Community attributes of the forest where H. sclerocarpum is found are scarcely known, as well as its similarity with other tropical seasonal forests. Question: What is the composition, structure, and diversity of the tropical deciduous forest where H. sclerocarpum is physiognomically dominant? Study site and date: The study was carried out in the buffer area of the Zicuirán-Infiernillo Biosphere Reserve, in the Churumuco municipality of Michoacán, Mexico (2014). Methods: In three 0.1-ha sites, we sampled trees with a diameter at breast height ≥ 1 cm and lianas whose rooted stem had a diameter of ≥ 1 cm. We calculated the density, biomass, rank-abundance, rank-basal area curves, and alpha and beta diversity measures for each site. Results: We recorded 64 species from 21 families in 0.3 ha. Fabaceae had the highest number of genera, species, individuals, and biomass in all sites sampled. The sites varied in richness (33-41 species), density (176-247 individuals), basal area (2-2.9 m2), and maximum height of trees (12-16 m). Rank-abundance curves differed significantly. Rarefaction curves showed that 0Dα and 1Dα did not differ among sites, while 2Dα separated one of the sites, which also showed a different diversity profile. Beta diversity did not show a strong species turnover among sites (0Dβ, 1.38-1.45; 2Dβ, 1.35-1.56). Conclusions: The composition of trees and shrubs in the forest sampled was similar to other seasonal forests, while the density and diversity were among the lowest values.

Basal area is a key measure of forest stocking and an important proxy of forest productivity in the face of climate change. Black walnut (Juglans nigra) is one of the most valuable timber species in North America. However, little is known about how the stocking of black walnut would change with differed bioclimatic conditions under climate change. In this study, we projected the current and future basal area of black walnut. We trained different machine learning models using more than 1.4 million tree records from 10,162 Forest Inventory and Analysis (FIA) sample plots and 42 spatially explicit bioclimate and other environmental attributes. We selected random forests (RF) as the final model to estimate the basal area of black walnut under climate change because RF had a higher coefficient of determination (R2), lower root mean square error (RMSE), and lower mean absolute error (MAE) than the other two models (XGBoost and linear regression). The most important variables to predict basal area were the mean annual temperature and precipitation, potential evapotranspiration, topology, and human footprint. Under two emission scenarios (Representative Concentration Pathway 4.5 and 8.5), the RF model projected that black walnut stocking would increase in the northern part of the current range in the USA by 2080, with a potential shift of species distribution range although uncertainty still exists due to unpredictable events, including extreme abiotic (heat, drought) and biotic (pests, disease) occurrences. Our models can be adapted to other hardwood tree species to predict tree changes in basal area based on future climate scenarios.