Pine Plantations Research Articles

Assessment of coal mining impact on the geoecological transformation of the Emerald network ecosystem

Purpose. Geoecological assessment of impact on the ecosystem transformation of a part of Emerald Network object “Samarskyi Lis – UA0000212” caused by coal mining at the section of “Ternivska” mine (Dnipropetrovsk region, Ukraine) using the methods of remote sensing of the Earth in conditions of limited access to the study object due to the state of martial law in Ukraine. Methodology. A complex of standardized field, paper, laboratory and statistical research methods was used. When studying aquatic vegetation, generally accepted methods for describing the species and coenotic composition of vegetation and hydrobotanical mapping were used. The study on soil vegetation was carried out with the selection and description of the main phytocenoses, features of their composition and distribution on the territory. Floristic studies were carried out according to the method for collecting herbarium material. Field routes were carried out on the land surface along the mining of the coal bed with the recording of destructive changes in the landscape (falls, top-soil breaks, sufosis manifestations, cracks, lowering of the relief) and plant groups – the colour and condition of tree, shrub and grass vegetation. In order to compare visual observation data and obtain representative and reliable research results, the facility was monitored additionally using modern geoinformation systems. A satellite observation tool was used; it allowed searching, processing, and obtaining information from satellite data according to various indexes: WRI, NDWI, MNDWI, NDSI. Findings. Negative consequences of the impact of the coal mine “Ternivska” on the geological and ecological transformation of the Emerald network ecosystem “Samarskyi Lis – UA0000212” have been established. It has been proven that long-term underflooding and flooding of lands leads to a change in the species composition of the forest stand, the death of the understory and grass layer, and the complete destruction of the existing plant and animal communities. In flooded areas of oak forests and pine plantations, forest species die out and wetland plant species spread. Over three years (2020–2023), the area of visible and established flooding according to remote sensing data has increased from 1 to 6 hectares, respectively. Originality. Dynamics of the process of the land surface subsidence and protected area flooding has been established according to the data of open-source geoinformation systems and the comparison of various satellite data indexes (WRI, NDWI, MNDWI, NDSI). Gradual changes in the species composition of the forest stand, the death of the understory and the grass layer were revealed. It has been confirmed that long-term flooding leads to the complete destruction of existing plant and animal communities, the destruction of compound complexes of soil mesofauna makes development impossible for the terrestrial invertebrate species that lived in these biotopes before their destruction, including species from the Red List of Ukraine and protected by the Berne Convention. Practical value. In the conditions of limited access for conducting direct geodetic and engineering-geological studies, the methodology of using modern GIS by combining various spectral channels (indexes) is substantiated to determine and study the dynamics of the underflooding (flooding) process in the territory. In combination with traditional field geobotanical research, the results of monitoring observations of the coal mining activity and its impact on the geoecological transformation of the ecosystem of the Emerald Network object are presented for the first time in the region. The negative impact of mining activity on natural conservation areas, which leads to the death and gradual change in the species composition of plants, has been determined.

Ecological stoichiometry of C, N, P and Si of Karst Masson pine forests: Insights for the forest management in southern China

Ecological stoichiometry is an effective method to study the stoichiometric relations and laws of elements in biogeochemical cycle, widely used in studies on nutrient cycles, limiting elements and nutrient utilization efficiency in ecosystems. To explore C, N, P, and Si stoichiometric characteristics and reveal these nutrient cycle processes and mechanisms in the karst Masson pine forests, the typical Masson pine forests of the three different stand ages in southern China were selected as the research objects and the C, N, P, and Si stoichiometric characteristics of soil-plant-litter continuum were studied. The followed results and conclusions were obtained: 1) Content range of TOC (total organic carbon), TN (total N), TP (Total P) and TSi (total Si) of the Masson pine forests was 288.31–334.61, 0.34–6.66, 0.11–1.05, and 0.76–11.4 g·kg−1, respectively. And the ratio range of C:N, C:P, C:Si, N:P, N:Si, and P:Si was 49.95–913.57, 99.98–2872.18, 22.48–429.31, 1.85–6.33, 0.17–6.01, and 0.04–0.91, respectively. 2) The significant differences in C, N, P, and Si stoichiometric characteristics were present between different organs or different forest ages. Leaves had the highest N and P content, while roots were the best enriched organ of Si element. Si content and C:Si were obviously correlated with forest age. 3) Significant N limitation was present in the Masson pine forests. And in the young and middle-aged forests, N limitation was more obvious. 4) The litter nutrients mainly came from branches. And the litter decomposed fast, which played an important role in the nutrient return of barren karst soil. The present results not only revealed the stoichiometric characteristics and cycling processes of C, N, P, and Si elements in the Masson pine forests, but also provided important scientific bases for the artificial management of Masson pine plantations in southern China.

Transpiration rates from mature Eucalyptus grandis × E. nitens clonal hybrid and Pinus elliottii plantations near the Two Streams Research Catchment, South Africa

Abstract. Pine plantations are the dominant species currently planted within the South African commercial forestry industry. Improvements in bio-economy markets for dissolving wood pulp products have seen an expansion in fast-growing Eucalyptus plantations due to their higher productivity rates and better pulping properties than pine. This has raised concerns regarding the expansion of Eucalyptus plantations and how they will affect water resources as they have been reported to have higher water use (quantified using transpiration rates) than pine. We measured transpiration rates (mm yr−1), diameter at breast height (quantified as quadratic mean diameter, Dq, m) and leaf area index of an 8-year-old Eucalyptus grandis × Eucalyptus nitens clonal hybrid (GN) and a 20-year-old Pinus elliottii. Transpiration rates were measured for two consecutive hydrological years (2019/20 and 2020/21) using a heat ratio sap-flow method, calibrated against a lysimeter. In the 2019/20 year, annual transpiration for P. elliottii exceeded GN by 28 %, while for the 2020/21 hydrological year, there was no significant difference between the transpiration of the two species, despite a 17 % and 21 % greater leaf area index for P. elliottii than GN in 2019/20 and 2020/21 measurement years respectively. Quadratic mean diameter increments were statistically similar (p > 0.05) in 2019/20, whereas the 2020/21 year produced significant differences (p<0.05). Tree transpiration is known to be influenced by climatic variables; therefore, a random forest regression model was used to test the level of influence between tree transpiration and climatic parameters. The soil water content, solar radiation and vapour pressure deficit were found to highly influence transpiration, suggesting these variables can be used in future water-use modelling studies. The profile water content recharge was influenced by rainfall events. After rainfall and soil profile water recharge, there was a rapid depletion of soil water by the GN trees, while the soil profile was depleted more gradually at the P. elliottii site. As a result, trees at the GN site appeared to be water stressed (reduced stem diameters and transpiration), suggesting that there was limited access to alternative water source (such as groundwater). The study concluded that previous long-term paired catchment studies indicate that eucalypts use more water than pine; however, periods of soil water stress and reduced transpiration observed in this study must be accommodated in hydrological models. Long-term total soil water balance studies are recommended in the same region to understand the long-term impact of commercial plantations on water resources.

Pine plantations and native forest fragments adjacent to intact forests provide surrogate habitats for birds in an Afrotropical forest landscape

AbstractTropical forests harbour 72% of the world's bird species. The changing land uses have fragmented natural forests or replaced them with plantation forests. This sets in an argument as to whether forest fragments and plantations can support birds. We assessed birds in a plantation, fragment and an intact (continuous) Budongo forest, Uganda. We compared bird species composition, diversity and functional traits between the forests and examined their response to habitat characteristics. We sampled birds using 135 point counts along nine transects and assessed habitat characteristics in 90 plots in the fragment and intact forest. We classified bird species according to habitat preference and feeding guild. Bird species composition differed between forests. Bird abundance and richness in plantation and fragment were lower than in intact forest. Forest specialists and insectivores dominated the intact forest. Most birds in the fragment were forest generalists and frugivores. Forest visitors and granivores dominated in the plantation. Trachyphorus purpuratus, Andropadus latirostris and A. curvirostris preferred sites with greater tree height, diameter and many snags, respectively. Bird species abundance and richness declined with increasing tree diameter and increased with snags. Forest specialists preferred sites without climbers. Thus, plantations and fragments close to intact forests provide surrogate habitats for bird conservation.

Modelling the hydrological impact of afforestation in hill country catchments in New Zealand

Study regionThree hill-country catchments in Waikato region, New Zealand Study focusLand use change (LUC), particularly the conversion of pastoral grazing land to plantation forestry, can significantly impact stream hydrology. Measuring the hydrological impact of LUC is time consuming and expensive. Modelling approaches provide a cost-effective means to determine and understand the mechanisms behind the impact of LUC on stream hydrology. In this study, we assessed the hydrological impact of LUC, mainly in the form of conversion of grazed pasture to plantation forest by using the Soil and Water Assessment Tool (SWAT). The effect of LUC on hydrology was evaluated by comparing model results under two scenarios: with and without LUC. New hydrological insights for the regionSWAT predicted the magnitude, occurrence, and variation of streamflow well at both daily and monthly time steps, before and after LUC periods. SWAT reported a significant reduction in streamflow due to converting pasture to pine plantation, which was mainly caused by increased evapotranspiration and reduced surface runoff. Predicted groundwater flow was affected by LUC but did not have a clear and consistent change. Our results are consistent with previous studies assessing the hydrological impact of afforestation, including one observation-based study from the same study site. This study illustrates the usefulness of dynamic hydrological modelling to evaluate LUC impact on hydrology, which is rarely available in New Zealand.

Fungal complexity and stability across afforestation areas in changing desert environments

The great achievements in combating desertification are attributed to large-scale afforestation, yet we lack verification of how the stability of the fungal community changes in afforestation areas in desert environments. Here, we present the fungal network structure from different niches (root and bulk soil) of plantations of Mongolian pine, a crucial species for afforestation introduced widely in desertification regions. We assessed changes in community complexity and stability of root-associated fungi (RAF) and soil fungi (SF) among different introduction sites: the Hulunbuir Desert (HB), the Horqin Desert (HQ) and the Mu Us Desert (MU). To illuminate the complexity and stability of the fungal network, the differences in topological properties, fungal function, and vegetation and environmental factors between introduction sites were fully considered. We showed that (1) the SF networks had more nodes and edges than the RAF networks. There was a lower ratio of negative:positive cohesion of RAF networks in HB and MU. For SF but not for RAF, across the three introduction sites, a higher modularity and ratio of negative:positive cohesion indicated higher stability. (2) Ectomycorrhizal (EcM) fungi were the dominant functional group in the RAF network (especially in HQ), and were only significantly correlated with vegetation factor. There was a higher relative abundance and number of OTUs of saprophytic fungi in the SF network and they showed positive correlations with soil nutrients. (3) RAF and SF network complexity and stability showed different responses to environmental and vegetation variables. The key determinant of the complexity and stability of the SF networks in Mongolian pine plantations was soil nutrients, followed by climate conditions. The composition and structure of the RAF community was closely related to host plants. Therefore, clarifying the complexity and stability of fungal communities in afforestation areas in changing desert environments is helpful for understanding the interactions between the environment, plants and fungi.

Climate-Sensitive Diameter Growth Models for White Spruce and White Pine Plantations

Global change in the climate is affecting tree/forest growth. There have been many studies that analyzed climate effects on tree growth. Results presented in these studies showed that the climate had both positive and negative effects on tree growth. The nature (positive/negative) and magnitude of the effects and the climate variables affecting growth depended on tree species. Climate-sensitive diameter growth models are not available for white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss) plantations. These models are needed to project forest growth and yield and develop forest management plans. Therefore, diameter growth models were developed for white pine and white spruce plantations by incorporating climate variables. Four hundred white pine and white spruce trees (200 per species) were sampled from 80 (40 per species) even-aged monospecific plantations (five trees per plantation) across Ontario, Canada. Diameter–age pairs were obtained from these trees using stem analysis. A nonlinear mixed-effects modeling approach was used to develop diameter growth models. To make the models climate sensitive, model parameters were expressed in term of climate variables. Inclusion of climate variables significantly improved model fit statistics and predictive accuracy. For evaluation, diameters (inside bark) at breast height were estimated for three geographic locations (east, west, and south) across Ontario for an 80-year growth period (2021–2100) under three climate change (emissions) scenarios (representative concentration pathway or RCP 2.6, 4.5, and 8.5 watts m−2). For both species, the overall climate effects were negative. For white spruce, the maximum pronounced difference in projected diameters after the 80-year growth period was in the west. At this location, compared to the no climate change scenario, projected spruce diameters under RCPs 2.6 and 8.5 were thinner by 4.64 (15.99%) and 3.72 (12.80%) cm, respectively. For white pine, the maximum difference was in the south. Compared to the no climate change scenario, projected pine diameters at age 80 under RCPs 2.6 and 8.5 at this location were narrower by 4.54 (13.99%) and 7.60 (23.43%) cm, respectively. For both species, climate effects on diameter growth were less evident at other locations. If the values of climate variables are unavailable, models fitted without climate variables can be used to estimate these diameters for both species.

Rove beetle communities (Coleoptera: Staphylinidae) in the rock dumps after coal mining

Rock dumps formed as a result of coal mining are unique model for studying the rove beetle communities. In total 60 species, 38 genera, 7 subfamilies of rove beetles were registered using soil traps. The greatest diversity of rove beetles was noted in forb-grass meadows (H` = 2.89) and pine plantations (H` = 2.39). The diversity of rove beetles was low (H` = 1.11) in birch and aspen-fir forests despite the greater number of revealed species. Only two eurytopic and mesophilic species (Drusilla canaliculata and Xantholinus linearis) were dominant in the rock dumps. Most of the rove beetles were eurytopic or forest species, zoophagous or mixophagous, mesophilous or hygrophilous. The number of eurytopic species and obligate predators increased, and the dynamic density of beetles decreased from older to younger dumps. The number of rove beetles depended on the soil temperature and humidity and the vegetation cover. Rove beetle communities are good indicators for monitoring the restoration of areas that have been technically degraded.

Factores relacionados con la variabilidad espacial del carbono orgánico del suelo en una microcuenca mexicana

Understanding the stocks of Soil Organic Carbon (SOC) and elucidating the variables influencing its spatial distribution within a small watershed are imperative for advancing targeted climate change mitigation strategies, specifically directed toward soil and water conservation. The selection of this watershed is predicated upon its three-decade-long implementation of diverse soil and water conservation practices. Therefore, the objective of this study was to analyze land use, vegetation cover, slope and soil and water conservation practices (SCWP) as factors that influence the variability and spatial distribution of soil organic carbon in a small basin in the Mixteca Alta region of the state of Oaxaca. Mexico. Soil samples (77) were collected to determine SOC storage. These samples were interpolated using the QGIS Smart-Map plugin to obtain a spatial COS predictive model. Thematic maps were generated for each factor. Areal statistics, Pearson’s correlation and principal component analysis (PCA) were performed to explain COS variability. The results in the variability of SOC with respect to vegetation cover and land use, showed adult pine plantations with the highest value of SOC with 36.8 t.ha-1, followed by seasonal agriculture with 28.8 t.ha-1. The most effective management practice for storing COS was the stone terrace with 35.0 t.ha-1. Our results indicate that vegetation cover and land use complemented by soil and water conservation practices are the main drivers of SOC storage in small watersheds.

Nitrogen addition suppresses soil positive priming effect in temperate plantations: Evidence from an 8‐year in situ field experiment

Abstract The microbial‐driven soil priming effect (PE) determines soil carbon emissions and is essential for accurately predicting the feedbacks between the terrestrial carbon cycle and global changes. In recent years, human activities have resulted in increased atmospheric nitrogen (N) deposition, but there is limited understanding of the long‐term effects of N deposition on soil microbial communities and their impact on soil PE in temperate plantations. This study utilized Korean pine plantation soils with 8 years of in situ N addition to investigate the mechanisms of the impact of long‐term N addition on PE through carbon (13C) isotope tracing and high‐throughput sequencing techniques. We found that N addition significantly changed the soil bacterial community structure, while the effect on the fungal community structure did not reach a significant level. Addition of 13C‐glucose resulted in soil‐positive PE, which exhibited a significant decreasing trend with increasing N addition. Compared with the control (0 kg N ha−1 year−1), the net carbon balance of the low N (20 kg N ha−1 year−1) showed no significant change, while the medium N (40 kg N ha−1 year−1) and high N (80 kg N ha−1 year−1) significantly increased by 35.47% and 35.79%, respectively, implying that glucose carbon was trapped in the soil much more than organic carbon decomposition. The PLS‐PM explained 69.0% of the total variation in PE among different N additions, showing that bacterial core taxa were the main driver of PE and that carbon enzyme activities (β‐1,4‐glucosidase and polyphenol oxidase) were a direct factor in regulating PE. Our results provide insights into accurately assessing the soil carbon sequestration potential of plantations under the influence of N deposition. Read the free Plain Language Summary for this article on the Journal blog.

Evaluating the effectiveness of different variable retention harvesting treatments on forest carbon uptake using remote sensing

Variable retention harvesting (VRH) is an ecologically based forest management practice applied to emulate natural post-disturbance residual canopy structure and increase the biodiversity and resilience of a regenerating stand. The pattern and density of canopy retention also influences the productivity, mortality, and carbon (C) sequestration rates of residual trees. In this study, we used high-resolution satellite and drone remote sensing data to evaluate the effect of five different VRH treatments on growth and C uptake of a 90-year-old red pine (Pinus resinosa Ait.) plantation forest in southern Ontario, Canada. The treatments included four different combinations of harvesting intensity residual tree distribution including 33% aggregate retention (33A), 55% aggregate retention (55A), 33% dispersed retention (33D), and 55% dispersed retention (55D) and unharvested control (CN) each replicated four times in 1 ha plots. Satellite- and drone-derived normal difference vegetation index (NDVI) and gross primary productivity (GPP) were estimated for each treatment during the growing seasons from 2010 to 2020. Over this period, observed mean daily NDVI values ranged from 0.25 to 0.86 among treatments, where the 55D treatment consistently showed the highest NDVI values. Overall, the highest mean daily GPP values were observed in the CN treatment, followed by the 55D, 55A, 33D, and 33A treatments. Remote sensing-derived mean annual GPP for the entire 20 ha study site was 1651 ± 89 g C m−2 year−1, with a range of 1407–1864 g C m−2 year−1 from 2010 to 2020. Satellite-derived annual GPP values were linearly related with observed annual GPP (R2 = 0.88, p = 0.032) measured using the eddy covariance technique in an adjacent white pine plantation of similar age and height over the study period. Study results suggested that VRH treatments that create a uniformly dispersed residual canopy retaining more than half of the initial basal area (e.g. 55D) is a viable forest management practice where optimizing forest growth and C uptake is a primary management objective. Our study will help forest managers and researchers to develop methodologies to evaluate the effectiveness of forest management practices, tailor them to achieve climate mitigation and adaptation goals and to develop forest management pathways for nature-based climate solutions.

Jointly soil properties affect N and P uptakes and utilizations in Pinus tabuliformis Carr. and Quercus liaotungensis Koidz. subjected to growing media with decomposed litter

Monocultured pine plantation is suffering ecological degradation that is highly associated with low regeneration. Decomposed litter is an important soil amendment for enhancing regeneration through promoting nitrogen (N) and phosphorus (P) uptakes and utilizations. It is necessary to detect key soil attributes that contributed to this positive effect for regenerations in pine plantations. In this study, in-situ soils and litter were collected from local Chinese pine (Pinus tabuliformis Carr.) plantations (objective) and secondary forests dominated by Liaodong oak (Quercus liaotungensis Koidz.) (control). Soils were used for culturing one-year-old Chinese pine and Liaodong oak seedlings with a prolonged photoperiod in a greenhouse. Litter was composted with effective microorganisms and mixed to soils at ratios of 0% (control), 25%, and 50% (v/v). Compared to the control, the 25% ratio decreased shoot height and root-collar diameter, and the 50% ratio decreased the comprehensive seedling quality. Decomposed litter addition reduced shoot biomass and P content in pine seedlings and utilizations for N and P in both species. Multivariate linear regression indicated that high pH in growing media impaired root P content and biomass increments in shoot and root parts, and high organic matter content inhibited N content and concentration in shoots. Overall, the addition of decomposed litter resulted in overdoses of nutrient supply for both species. Our results contradict the argument that N and P released from decomposed litter are both beneficial for regenerations in plantations, neither did in secondary forests.

Динамика нижних ярусов растительного покрова в антропогенно нарушенных сосновых ценозах Красноярской лесостепи

The dynamics of the understorey vegetation cover in anthropogenically transformed cenoses of common pine (Pinus sylvestris L.) in the period 2017–2020 was studied. The studies were conducted in a diverse herbaceous group of forest types of natural origin in the Krasnoyarsk forest-steppe zone. The forest stands are characterized by I–IV classes of bonitet, density 0.5–0.9 and IV–VII class of age. Vegetation cover was studied at each monitoring site on 30 (1 m2) survey plots: species composition, projective cover, species occurrence, horizontal and vertical structure of phytocenosis. The intensity of change in species composition over a 4-year period was identified using the Serensen-Chekanovsky coefficient. Species diversity was assessed using Shannon index, recreational transformation of living ground cover – synanthropization index. Based on the results of the study, the species composition of the undergrowth and living ground cover was determined, and the features of its change in the period 2017–2020 were described. Based on the analysis of changes in species diversity, composition and projective cover of dominants and co-dominants, quantitative ratio of ecological and cenotic groups, the stages of recreational transformation of the ground cover were determined. As a result of the increased recreational load, the stage of recreational transformation of the vegetation cover changed: in sample area 1 from undisturbed to the 1st (initial) phase I stage (weak transformation), in sample area 3 – from the 1st to the 2nd (final) phase I stage. Due to the absence of anthropogenic influence, the undisturbed vegetation cover was preserved in sample area 4, whereas in sample areas 2 and 5, due to the constant recreational load, the 2nd phase I stage of vegetation cover transformation observed in 2017 remained. To reduce the impact on the lower tiers of vegetation under the canopy of pine plantations (sample areas 1–3) and to preserve its species diversity, it is possible to recommend the arrangement of a specific road-trail network. For citation: Goncharova I.A., Skripalschikova L.N., Barchenkov A.P. Dynamics of Understory Vegetation Cover in Anthropogenically Disturbed Pine Cenoses of Krasnoyarsk Forest-Steppe. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 6, pp. 204–214. (In Russ.). https://doi.org/10.37482/0536-1036-2023-6-204-214

Time will tell: Taxonomic and functional diversity of monilophyte ferns in native forests and abandoned silviculture systems

AbstractDifferent forest systems can influence the function, traits, diversity, and distribution of ferns. By comparing ferns based on their functional traits, we can explore how species loss affects functional diversity, and consequently alter the forest ecosystem. We investigated the impact of abandoned silviculture on fern diversity (taxonomic and functional) and abundance. Our hypothesis suggests a positive effect of nutrients and soil humidity in native forests, while canopy openness in silviculture has a negative effect on monilophyte diversity. This study was conducted in three sites of native forest and three sites of Pinus silviculture. Each site was subdivided into three areas, with three plots per area, resulting in 54 plots (3 sites × 3 areas × 3 plots × 2 forest types). Each plot covered an area of 100 m2 (10 m × 10 m; 5400 m2 in total). In each plot, we estimated abundance, functional attributes (richness, evenness, divergence, and dispersion) based on leaf thickness, leaf width, petiole length, stem length, leaf division, sori shape, indusium presence, and taxonomic diversity. Results indicate that native forest exhibit higher taxonomic and functional diversity (richness—Fric) compared to abandoned Pinus plantations, which may be attributed to high habitat diversity and species specialization in specific microhabitats. In silviculture, diversity homogenization leads to an increase in the redundancy of functional attributes (evenness—Feve), resulting in the filtering out of similar organisms. Abiotic factors such as light and canopy openness negatively influence plant establishment and growth, leading to a decrease in leaf division and indusium presence/absence (by CWMs), supporting niche complementarity theory in natural forest and mass ratio theory in silviculture. Our findings highlight the enduring negative impact of silviculture, even after 20 years, on both the taxonomic and functional diversity of monilophytes, underscoring the crucial role of native forests in preserving fern diversity.

Ectomycorrhizal fungi enhance pine growth by stimulating iron-dependent mechanisms with trade-offs in symbiotic performance.

Iron (Fe) is crucial for metabolic functions of living organisms. Plants access occluded Fe through interactions with rhizosphere microorganisms and symbionts. Yet, the interplay between Fe addition and plant-mycorrhizal interactions, especially the molecular mechanisms underlying mycorrhiza-assisted Fe processing in plants, remains largely unexplored. We conducted mesocosms in Pinus plants inoculated with different ectomycorrhizal fungi (EMF) Suillus species under conditions with and without Fe coatings. Meta-transcriptomic, biogeochemical, and X-ray fluorescence imaging analyses were applied to investigate early-stage mycorrhizal roots. While Fe addition promoted Pinus growth, it concurrently reduced mycorrhiza formation rate, symbiosis-related metabolites in plant roots, and aboveground plant carbon and macronutrient content. This suggested potential trade-offs between Fe-enhanced plant growth and symbiotic performance. However, the extent of this trade-off may depend on interactions between host plants and EMF species. Interestingly, dual EMF species were more effective at facilitating plant Fe uptake by inducing diverse Fe-related functions than single-EMF species. This subsequently triggered various Fe-dependent physiological and biochemical processes in Pinus roots, significantly contributing to Pinus growth. However, this resulted in a greater carbon allocation to roots, relatively reducing the aboveground plant carbon content. Our study offers critical insights into how EMF communities rebalance benefits of Fe-induced effects on symbiotic partners.

The Effect of Grey Heron Colonies on the Radial Growth of Trees in Pine Plantations

The Effect of Grey Heron Colonies on the Radial Growth of Trees in Pine Plantations

Long-term N addition reduced the diversity of arbuscular mycorrhizal fungi and understory herbs of a Korean pine plantation in northern China

With the development of agriculture and industry, the increase in nitrogen (N) deposition has caused widespread concern among scientists. Although emission reduction policies have slowed N releases in Europe and North America, the threat to biodiversity cannot be ignored. Arbuscular mycorrhizal (AM) fungi play an important role in the establishment and maintenance of plant communities in forest ecosystems, and both their distribution and diversity have vital ecological functions. Therefore, we analyzed the effects of long-term N addition on AM fungi and understory herbaceous plants in a Korean pine plantation in northern China. The soil properties, community structure, and diversity of AM fungi and understory herbaceous plants were detected at different concentrations of NH4NO3 (0, 20, 40, 80 kg N ha−1 year−1) after 7 years. The results showed that long-term N deposition decreased soil pH, increased soil ammonium content, and caused significant fluctuations in P elements. N deposition improved the stability of soil aggregates by increasing the content of glomalin-related soil protein (GRSP) and changed the AM fungal community composition. The Glomus genus was more adaptable to the acidic soil treated with the highest N concentration. The species of AM fungi, understory herbaceous plants, and the biomass of fine roots were decreased under long-term N deposition. The fine root biomass was reduced by 78.6% in the highest N concentration treatment. In summary, we concluded that long-term N deposition could alter soil pH, the distribution of N, P elements, and the soil aggregate fractions, and reduce AM fungal and understory herb diversity. The importance of AM fungi in maintaining forest ecosystem diversity was verified under long-term N deposition.

The response of needle stoichiometry to 10-year N addition and 4-year cessation of N addition in a subtropical Masson pine plantation of China

The response of needle stoichiometry to 10-year N addition and 4-year cessation of N addition in a subtropical Masson pine plantation of China

Metal cation concentrations improve understanding of controls on soil organic carbon across a precipitation by vegetation gradient in the Patagonian Andes

Tephra-derived soils retain more organic carbon (C) than soils formed from any other parent material, but this C may be sensitive to changes in climate and land use. Here we evaluate the effects of precipitation, temperature, and afforestation on extractable metals and organic C storage in young tephra-derived soils in a temperate climate. We conducted our investigation across five sites in the Patagonian Andes that vary from 250 mm to 2200 mm mean annual precipitation, and 12 to 9.7 ℃ mean annual temperature from east to west. At each of the five sites are paired plots of natural vegetation, varying from grasses and shrubs at the dry sites to closed-canopy forest at the wet, and stands of Pinus ponderosa planted in monocultures 35 years prior to sampling. Previous research at these sites showed that aboveground net primary production and soil organic C increased with rainfall, but total soil organic C content was lower in pine plantations than natural vegetation. Here we assess whether variation in precipitation and vegetation type also affect soil mineral properties that promote soil C stabilization. Soils were collected to the depth of auger refusal and extracted with 0.5 M HCl for 24 h to target the combined exchangeable and adsorbed metals, including secondary short-range-ordered mineral phases and the plant available pools of Mg, Ca, and K. Pine afforestation lowered concentrations of HCl-extractable K (p < 0.1) and Ca (p < 0.01) within the top 0 – 30 cm. Other elements, while not affected by vegetation type, did respond to the rainfall gradient. Al, Si, P, and Mn all increased in the surface soils with increasing rainfall (p < 0.01), suggesting the development of short-range-order volcanic mineral phases that retain nutrients such as P and Mn. The addition of Al and Ca in the linear model to describe soil organic C explained more of the total variance than rainfall and vegetation type alone, indicating the importance of Al complexes and cation (Ca) bridging with secondary minerals to soil C retention. Importantly, the lower concentration of Ca in planted pine soils may signal a long-term decrease in the potential soil C stored in afforested soils due to a lower capacity for cation bridging. Our results show that the chemistry of these young tephra soils is dynamic, responding to both precipitation and afforestation in distinct ways with potential long-term impacts on nutrient cycling and C storage.

Analysis of the commercial eucalyptus plantation sector in Uruguay from a macroeconomic perspective

The Uruguayan forest sector has developed based on commercial pine and eucalyptus plantations. This process has been based on the installation of vertically integrated companies, with foreign capital and some local capital, investment funds and medium and small industries. In addition to these groups, there are contractor companies in which several of the activities of the primary sector are outsourced, as well as some of the industry. Investment attraction factors are diverse and related not only to productive conditions, e.g., growth rates, but also to institutional conditions, e.g., macroeconomic stability. With the development of the forest sector, there is currently a preponderance of eucalyptus plantations over pine plantations. This characteristic has implications in terms of the products to be obtained and, therefore, the industries to be developed, and the markets to be accessed. The presentation analyzes the evolution of the participation of the forest sector in Uruguay's macroeconomy, considering its share in the country's exports as well as in international trade, with emphasis on the products obtained from eucalyptus plantations. The scope and limitations of the available data for Uruguay are considered. Finally, the importance of including the value of ecosystem services provided by the forest in the traditional macroeconomic valuation is discussed. Results show that Uruguay has an important participation in non-coniferous wood markets. According to FAO data, in 2022, Uruguay's production ranked 8th among non-coniferous pulpwood producing countries, after Chile, up one place from the previous year. The same year Uruguay ranked 10th in terms of production of bleached wood pulp. Furthermore, it is expected that the wood pulp will increase with the new operations of the third pulp mill. Furthermore, cellulose pulp ranked 3rd among Uruguay's export products in 2022, after beef and soybeans, and 2nd in the previous year. The results of this research are of interest to potential investors in the Uruguayan forest sector as well as to policymakers. Potential investors in the Uruguayan forest sector may find insights into the industry's growth potential. Policymakers can use this information to make informed decisions that support the development and regulation of the sector for the benefit of both the economy and the environment.