Forest Plantations Research Articles

Comparison of freshwater diatom assemblage between old-growth broad-leaved and planted coniferous forest basins in temperate region, Japan

Various forest types are distributed in headwater streams. However, differences in diatom assemblages among forest types in Japan have not been thoroughly investigated. The objective of this study was to determine differences in diatom assemblages in the most common forest types in Japanese headwater streams, old-growth broadleaf forest (OBF) and planted coniferous forest (PCF) types, and to identify diatom species that tend to grow in either the OBF or PCF forest types. Diatom abundance differed between the forest types, but the numbers of species, genera and families did not. Nonmetric multidimensional scaling analysis revealed the differences in diatom assemblages in OBF and PCF types and this difference was brought by particularly of some genera such as Gomphonema, Planothidium and Navicula. Differences in diatom assemblages between the two forest types were considered to be a reflection of the different environmental conditions such as light condition and alkalinity, created by the different forest types.

Remote sensing data fusion approach for estimating forest degradation: a case study of boreal forests damaged by Polygraphus proximus

In the context of global climate change and rising anthropogenic loads, outbreaks of both endemic and invasive pests, pathogens, and diseases pose an increasing threat to the health, resilience, and productivity of natural forests and forest plantations worldwide. The effective management of such threats depends on the opportunity for early-stage action helping to limit the damage expand, which is difficult to implement for large territories. Recognition technologies based on the analysis of Earth observation data are the basis for effective tools for monitoring the spread of degradation processes, supporting pest population control, forest management, and conservation strategies in general. In this study, we present a machine learning-based approach for recognizing damaged forests using open source remote sensing images of Sentinel-2 supported with Google Earth data on the example of bark beetle, Polygraphus proximus Blandford, polygraph. For the algorithm development, we first investigated and annotated images in channels corresponding to natural color perception—red, green, and blue—available at Google Earth. Deep neural networks were applied in two problem formulations: semantic segmentation and detection. As a result of conducted experiments, we developed a model that is effective for a quantitative assessment of the changes in target objects with high accuracy, achieving 84.56% of F1-score, determining the number of damaged trees and estimating the areas occupied by withered stands. The obtained damage masks were further integrated with medium-resolution Sentinel-2 images and achieved 81.26% of accuracy, which opened the opportunity for operational monitoring systems to recognize damaged forests in the region, making the solution both rapid and cost-effective. Additionally, a unique annotated dataset has been collected to recognize forest areas damaged by the polygraph in the region of study.

Plasticity of leaf functional traits and growth responses to disturbance among cutting cultivars of Cryptomeria japonica in southern Japan

ABSTRACT Cryptomeria japonica (Thunb. ex L. f.) D. Don is the most major plantation species in Japan, and cultivars have been developed and planted under variable environmental conditions across the country. Productivity of clonal plantations is influenced by the ability of the genotype to acclimate to edaphic- and geographic-scale variation in environmental conditions and disturbance regimes. Because all individuals are genetically identical in a clonal plantation, the trait differences among individuals represent phenotypic plasticity. Here, we investigated how phenotypic plasticity and response to disturbance vary among cutting cultivars of C. japonica. We compared tree height, leaf morphology, nitrogen content, and frequency/intensity of growth-release observed in tree rings after thinning and disturbance among six cutting cultivars in 45-year-old provenance trials in south-western Japan. Nitrogen use efficiency was higher in the site where maximum tree height (H max) was taller, while shoot mass per area (SMA) was larger in the site where H max was shorter. Cultivars that grew well had high leaf nitrogen content (N G) and showed more efficient nitrogen use with high nitrogen-resorption efficiency (NRE). Yabukuguri, an intermediate-growth cultivar, was characterized by large SMA and greater plasticity in SMA and tree height in response to topographical and regional variation, as well as greater intensity of growth-release in tree-ring series indicating growth resilience following disturbance. Our results provide guidelines for selecting cultivars with high acclimation potential and resilience to environmental perturbation, which is important for sustaining plantation forests in uncertain environmental conditions expected by future climate change.

Origin and Persistence of Lycopodium clavatum and Lycopodium annotinum (Lycopodiaceae) in Scots Pine Forests.

Understanding the growth dynamics of spore-bearing clonal plant sporophytes and the influence of abiotic and biotic factors is crucial for predicting the persistence of club moss populations and implementing effective habitat management techniques. Despite this, the longevity and development of club-moss populations are rarely studied. This study adopted an integrated approach to assess the probability of repetitive young sporophyte recruitment via sexual propagation in Lycopodium annotinum L. and Lycopodium clavatum L. The size-age problem of clonal spore-bearing forest plants and their niche segregation were addressed. The canopy characteristics, insolation, small-scale disturbance, and genetic polymorphism were studied in temperate semi-natural Scots pine forests in Lithuania. Based on the size of the clones discovered, we hypothesize that initial sporophyte emergence occurred in 20-year-old pine stands, with subsequent sporophyte emergence continuing over time. The emergence was related to small-scale disturbances. High genetic polymorphism indicates that all sporophyte stands studied likely emerged via sexual reproduction. According to Ellenberg values, L. annotinum is related to shady habitats, but our findings show both species coexisting abundantly in the more open habitat, supposedly more suitable for L. clavatum.No significant differences in vegetation relevés and light availability was detected using hemispheric images.

FORECASTING CHANGE IN THE LEVEL OF FOREST COVERAGE USING THE GLOBAL FOREST WATCH SERVICE AND THE PROGRAMMING AND DATA ANALYSIS LANGUAGE R

The problem of calculating the level of forest cover is considered, including forecasting changes in forest cover in individual forestry. It is stated that the authors previously developed software for calculating forest cover and processing information about forest plantations using the example of the village of Spivakivka in the Izyum district of the Kharkiv region. A comparison of forest cover over a number of years was also made using the Global Forest Watch resource. From this resource, images of Prydonetsk Forestry were taken with conventional designations: areas where new forest plantations are being planted are shown in blue, and areas where cutting is taking place are shown in pink. It is proposed to divide each of the uploaded images of the selected forestry into squares, and then analyze the data for each square. The pink color saturation was calculated and stored in the table. It is noted that forecasting the change in forest stands on the selected site, that is, the change in the percentage of felling, can be done in different ways. First, use regression analysis - apply the regression equation separately to the values of each square, as well as to the entire forestry. Secondly, to form a list of input factors containing indicators on the selected plot in the two previous years and the same indicators on neighboring plots. Thus, the number of factors will be equal to 27: 26 input and 1 output (values on the studied square). Such a forecasting problem can be solved either by the method of multivariate linear regression or by the method of artificial neural networks. The R programming and data analysis language was used to perform calculations using both methods. A script was created that performs calculations by constructing regression lines and an artificial neural network, and also allows determining the best architecture of a neural network and a more effective method of its training for a certain data set. The calculation of the felling dynamics in the entire forestry (the forecast for the last year provides an error of 1 %) and the calculation of the felling dynamics in the selected square (the forecast for the last year provides an error of 3.5 %) are given. After many runs of the script, it was found that the best result is provided by a perceptron with two hidden layers and two neurons in each layer. The results of the calculations indicate a high correlation of the data for determining the percentage of forest that will be cut down in a certain square. Application of this perceptron for forecasting for the last year showed an error of 3 %.

Impacts of deforestation and land use/land cover change on carbon stock dynamics in Jomoro District, Ghana

Tropical deforestation in the African continent plays a key role in the global carbon cycle and bears significant implications in terms of climate change and sustainable development. Especially in Sub-Saharan Africa, where more than two-thirds of the population rely on forest and woodland resources for their livelihoods, deforestation and land use changes for crop production lead to a substantial loss of ecosystem-level carbon stock. Unfortunately, the impacts of deforestation and land use change can be more critical than in any other region, but these are poorly quantified. We analyse changes in the main carbon pools (above- and below-ground, soil and litter, respectively) after deforestation and land use/land cover change, for the Jomoro District (Ghana), by assessing the initial reference level of carbon stock for primary forest and the subsequent stock changes and dynamics as a consequence of conversion to the secondary forest and to five different tree plantations (rubber, coconut, cocoa, oil palm, and mixed plantations) on a total of 72 plots. Results indicate overall a statistically significant carbon loss across all the land uses/covers and for all the carbon pools compared to the primary forest with the total carbon stock loss ranging between 35% and 85% but with no statistically significant differences observed in the comparison between primary forest and mixed plantations and secondary forest. Results also suggest that above-ground carbon and soil organic carbon are the primary pools contributing to the total carbon stocks but with opposite trends of carbon loss and accumulation. Strategies for sustainable development, policies to reduce emissions from deforestation and forest degradation, carbon stock enhancement (REDD+), and planning for sustainable land use management should carefully consider the type of conversion and carbon stock dynamics behind land use change for a win-win strategy while preserving carbon stocks potential in tropical ecosystems.

Understanding the influence of environmental factors on forest composition along the vertical gradient of Northwestern Himalaya

Temperate and alpine ecosystems are considered the most sensitive and vulnerable region towards climate change in the Indian Himalayan region. The current study investigates forest composition in relation to environmental and edaphic factors, which is critical for determining plant community patterns. The impact of climatic and soil properties was studied to better understand species diversity and composition over an elevational gradient (2500–4800 m) in Beas Valley, Northwestern Himalaya. A total of 181 species from 15 community types, representing 122 genera and 53 families (9 Trees, 13 shrubs, and 142 herbs) were recorded from the valley. Non-metric multidimensional scaling (NMDS) analysis revealed significant compositional dissimilarity (PseudoF = 10.16, R2 = 0.48, p < 0.001) among vegetation types. Structural equation modeling (SEM) results indicated that tree species diversity was significantly influenced by solar radiation (β=0.17, p = 0.001) and winter temperature (β=41.95, p = 0.017). It was observed that solar radiation and winter temperature shape the community types in high elevation temperate regions. In contrast, precipitation, solar radiation along with summer temperature determine the composition of sub-alpine communities, whereas solar radiation, winter temperature and soil pH determine the composition of alpine communities. This indicated that multiple environmental factors are responsible for this diversity. The research findings shed light on crucial factors influencing high elevation plant diversity, emphasizing the significance of understanding environmental correlations for effective conservation. This is pioneer study, which will act as a reference for future studies in Beas valley. This scientific foundation allows for prioritized conservation efforts, focusing on areas with specific environmental conditions influencing forest composition and plant diversity, ultimately contributing to better management and preservation of high elevation plant communities.

Current expansions in the Brazilian timber market

The attractive financial returns from timberland investments in Brazil, particularly fast-growth tree plantations like pine and eucalyptus, have attracted multiple investors over the last decade. Among the countries with a competitive Pulp and Paper Industry (PPI), pulp and paper investors have expanded substantially in Brazil with new mills and planted areas. This paper presents a comprehensive investigation of the dynamics of the Brazilian pulp and paper industry forest sector in the past decade. We described the current macroeconomic and political environment in Brazil and the expansion of mills and timberland in Brazil. Brazil is, clearly, among the selective countries where a substantial expansion of the forest sector is possible. The regions like Mato Grosso do Sul have impressive scales of productivity and expansion. Other areas, like the states of Maranhão, Piaui, Tocantins and Bahia present potential to expand forest plantation, however, they are limited by weather constraints (extensive drought and fire seasons). Even well-known markets, like the South region of Brazil, have has opportunities to expansion subject to higher land prices. Brazil’s attractiveness for timberland investments is underscored by robust economic indicators and extensive natural resources. Yet, navigating the complexities of its political landscape remains a critical consideration for potential investors looking to capitalize on the country’s promising forestry sector.

Mechanisms of litter input changes on soil organic carbon dynamics: a microbial carbon use efficiency-based perspective

Plant litter is an important source of soil organic carbon (SOC) in terrestrial ecosystems, and the pattern of litter inputs is also influenced by global change and human activities. However, the current understanding of the impact of changes in litter inputs on SOC dynamics remains contentious, and the mechanisms by which changes in litter inputs affect SOC have rarely been investigated from the perspective of microbial carbon use efficiency (CUE). We conducted a 1-year experiment with litter treatments (no aboveground litter (NL), natural aboveground litter (CK), and double aboveground litter (DL)) in Robinia pseudoacacia plantation forest on the Loess Plateau. The objective was to assess how changes in litter input affect SOC accumulation in forest soils from the perspective of microbial CUE. Results showed that NL increased soil microbial C limitation by 77.11 % (0–10 cm) compared to CK, while it had a negligible effect on nitrogen and phosphorus limitation. In contrast, DL had no significant effect on soil microbial nutrient limitation. Furthermore, NL was found to significantly increase microbial CUE and decrease microbial metabolic quotient (QCO2), while the opposite was observed with DL. It is noteworthy that NL significantly contributed to an increase in SOC of 30.72 %, while DL had no significant effect on SOC. Correlation analysis showed that CUE was directly proportional to SOC and inversely proportional to QCO2. The partial least squares pathway model indicated that NL indirectly regulated the accumulation of SOC, mainly through two pathways: promoting microbial CUE increase and reducing QCO2. Overall, this study elucidates the mechanism and novel insights regarding SOC accumulation under changes in litter input from the perspective of microbial CUE. These findings are critical for further comprehension of soil carbon dynamics and the terrestrial C-cycle.

Nitrogen availability and its related enzyme activities affect microbial residue nitrogen accumulation during Chinese fir plantation development

Microbial growth, metabolism, and reproductive activities have a significant role in the generation, transformation, and storage of soil nitrogen (N). However, the time-integrated effect of microorganisms on long-term N sequestration in plantation forests remains poorly understood. We investigated the microbial residue N (MRN) and its contribution to soil total N (TN) among the young (8-year), middle (16-year), near-mature (24-year), mature (34-year), and over-mature (106-year) stands of Chinese fir plantation (CFP) in subtropical China. The soil TN content showed a general pattern of increasing with stand age, ranging from 2.61 to 3.42 g kg−1, and was higher in the over-mature and mature stands than in the other three stands (p < 0.001). In addition, soil carbon (C), N, phosphorus (P), and hydrolase stoichiometric ratios indicated that P limitation was widespread during all stages of CFP development. The average ratio of soil fungal residue N (FRN) to bacterial residue N (BRN) was 3.64:1. The MRN content and its contribution to soil TN exhibited a falling and then rising pattern from young to over-mature stands, ranging from 1.24 to 1.70 g kg−1 and 38.8 % to 57.5 %, respectively. Soil N fraction contents and hydrolase activities were higher in the 0–5 cm soil layer than in the 5–30 cm soil layer (p < 0.05). Regression analysis showed that soil MRN content increased with soil N fraction contents, C-N-P stoichiometric ratios, and hydrolase activities (p < 0.001). Redundancy analysis and partial least squares path modeling revealed that soil available N (AN) and N hydrolase were the main factors affecting MRN accumulation. These parameters may partially indicate the dynamics of MRN accumulation. Our study discovered that the long-term development of CFP promotes soil N sequestration, with microbial residues playing a significant role in contributing to N pools.

Seasonal variations affect the ecosystem functioning and microbial assembly processes in plantation forest soils.

While afforestation mitigates climate concerns, the impact of afforestation on ecological assembly processes and multiple soil functions (multifunctionality) in afforested areas remains unclear. The Xiong'an New Area plantation forests (Pinus and Sophora forests) in North China were selected to examine the effects of plantation types across four distinct seasons on soil microbiomes. Three functional categories (nutrient stocks, organic matter decomposition, and microbial functional genes) of multifunctionality and the average (net) multifunctionality were quantified. All these categories are directly related to soil functions. The results showed that net soil multifunctionality as a broad function did not change seasonally, unlike other narrow functional categories. Bacterial communities were deterministically (variable selection and homogenous selection) structured, whereas the stochastic process of dispersal limitation was mainly responsible for the assembly and turnover of fungal and protist communities. In Pinus forests, winter initiates a sudden shift from deterministic to stochastic processes in bacterial community assembly, accompanied by decreased Shannon diversity and heightened nutrient cycling (nutrient stocks and organic matter decomposition). This indicates the potential vulnerability of deterministic assembly to seasonal fluctuations, particularly in environments rich in nutrients. The results predicted that protist community composition was uniquely structured with C-related functional activities relative to bacterial and fungal β-diversity variations, which were mostly explained by seasonal variations. Our study highlighted the importance of the protist phagocytosis process on soil microbial interactions through the predicted impact of protist α-diversity on microbial cooccurrence network parameters. This association might be driven by the high abundance of protist consumers as the main predators of bacterial and fungal lineages in our sampling plots. Our findings reveal that the complexity of microbial co-occurrence interactions was considerably higher in spring, perhaps attributing thermal variability and increased resource availability within spring that foster microbial diversity and network complexity. This study contributes to local ecosystem prospects to model the behavior of soil biota seasonally and their implied effects on soil functioning and microbial assembly processes, which will benefit global-scale afforestation programs by promoting novel, precise, and rational plantation forests for future environmental sustainability and self-sufficiency.

Leveraging Google Earth Engine and Machine Learning to Estimate Evapotranspiration in a Commercial Forest Plantation

Leveraging Google Earth Engine and Machine Learning to Estimate Evapotranspiration in a Commercial Forest Plantation

Soil Fungal Function Centralization Enhances the Decomposition of Fine Roots at Canopy Gap Borders

Canopy gaps can result in abiotic heterogeneities and diverse niches from gap borders to centers, potentially affecting fine root decompositions mediated by soil fungal communities. Despite extensive discussions on the relationship between soil fungi and fine root decomposition, the mechanism by which gap locations regulate fine root decomposition through the soil fungal community remains elusive. Here, we conducted an in situ field decomposition experiment of Chinese Toon (Toona senensis) fine roots in a low-efficiency weeping cypress (Cupressus funebris) plantation forest across three microhabitats: gap centers, gap borders, and closed canopy areas. Soil fungal communities were determined using internal transcribed spacer (ITS) sequencing after two years of field incubation. Results showed that soil properties and nutrient content in residual roots varied across the three microhabitats, with the gap borders exhibiting the highest decomposition rates. While fungal α-diversity remained relatively consistent, taxonomic compositions differed significantly. Decomposition rates did not show significant correlations with soil properties, observed fungal ASVs, or overall community composition. However, they positively correlated with the relative abundance of saprotrophic Sordariomycetes, which in turn positively correlated with soil total nitrogen (with a highest correlation), peaking at the gap borders. Overall community variations were primarily driven by soil temperature and magnesium content in residual roots. Further analysis revealed high fungal community similarities and low dispersal limitations between the gap borders and closed canopy areas, with more phylogenetically clustered communities at the borders. These results demonstrate that the gap borders possess a high decomposition rate, likely due to the centralization of functions driven by soil fungi such as saprotrophs existing in the “microbial seed bank” or migrating from closed canopy areas. These findings highlight the key role of soil fungi, especially saprotrophic fungi, in fine root decomposition at the gap borders, stressing the importance of soil fungi-driven mechanisms in nutrient cycling, and also informing sustainable forest management practices.

Cost-effectiveness of natural forest regeneration and plantations for climate mitigation

Mitigating climate change cost-effectively requires identifying least-cost-per-ton GHG abatement methods. Here, we estimate and map GHG abatement cost (US$ per tCO2) for two common reforestation methods: natural regeneration and plantations. We do so by producing and integrating new maps of implementation costs and opportunity costs of reforestation, likely plantation genus and carbon accumulation by means of natural regeneration and plantations, accounting for storage in harvested wood products. We find natural regeneration (46%) and plantations (54%) would each have lower abatement cost across about half the area considered suitable for reforestation of 138 low- and middle-income countries. Using the more cost-effective method at each location, the 30 year, time-discounted abatement potential of reforestation below US$50 per tCO2 is 31.4 GtCO2 (24.2–34.3 GtCO2 below US$20–100 per tCO2)—44% more than natural regeneration alone or 39% more than plantations alone. We find that reforestation offers 10.3 (2.8) times more abatement below US$20 per tCO2 (US$50 per tCO2) than the most recent IPCC estimate.

Семенная продуктивность и качество семян Pinus sylvestris L. в лесных культурах на крымских яйлах

The seed production and quality of Pinus sylvestris seeds in forest plantations on the Crimean yaylas has been studied. The dynamics of biometric indicators of cones and seeds by year and in connection with the peculiarities of growing conditions has been characterized. Significant differences in the quality of seeds of P. sylvestris trees have been revealed in terms of the level of germination energy. It has been shown that, along with the temperature regime, a significant impact on the effectiveness of P. sylvestris reproduction processes is exerted by air humidity and the nature of precipitation, as well as the dynamics of air mass movement, since the success of pollination is determined by the quantity and quality of pollen that has reached the female reproductive structures. Based on the analysis of weather phenomena and the dynamics of seed quality, it has been found that the level of seed germination is best reflected by an integrated index that takes into account the combined effect of several factors – the dryness index. In addition, the results of the analysis allowed us to conclude that the efficiency of the pollination process of female cones of P. sylvestris under yayla conditions is most likely influenced by the number of hours of sunshine. The germination energy and seed germination differ not only within the studied plantations, but also depending on the year of study. During the observation period, the forest plantations of the Ai-Petrinskaya Yayla have produced the highest quality seeds. In 2014, in the plantations with a density of 0.5, the seed germination rate was 74.5±2.2 %. The lowest level of germination energy and seed germination has been noted in artificial plantations of P. sylvestris on the Tirke Yayla; in 2012, these indicators here amounted to 15.2±0.7 and 46.2±2.1 %, respectively. In general, the development of the generative sphere of P. sylvestris in artificial plantations on the Crimean yaylas is quite effective. Based on this, a conclusion has been made that the growing conditions on the yaylas are favourable for the implementation of the initial stages of the ontogenesis of the species.

Лесохозяйственные мероприятия в полезащитных лесных полосах Краснодарского края

In the process of growth and development of forest belts, some of their taxation characteristics and design change. Forest reclamation complexes are subject to homeostasis. Changing the design of shelterbelts leads to crop shortages, loss of profits for agricultural organizations, as well as to the deterioration of the ecology of field soils. A way out of this situation can be found in the application of a system of measures, an important part of which is forestry measures. The aim of the research has been to determine the timing and types of forestry measures aimed at improving the agro-ecological efficiency of protective forest reclamation complexes on agricultural lands of the Krasnodar Territory. Data from the 2019 inventory of protective forest plantations and data obtained by the authors in 2015–2021 in the Kushchevskij and Leningradskij Districts of the Krasnodar Territory have been used. According to the data obtained, graphs of the dependence of stock on the age and height have been constructed for some tree species of field protection forest reclamation complexes. It has been established that in the study area the largest number of areas of shelterbelts have a dense structure – 538.5 ha, and 501.7 ha of them are trees of the III age class. A significant increase in the stock of plantations has been noted at the age of: Robinia pseudoacacia L. – 15 years, Fraxinus excelsior L. – 25 years, Gleditsia triacanthos L. – 10 years, Ulmus pumila L. – 35 years. The equations of the regressional dependence of stock on the age and height for the main tree species have been obtained. These equations can be used to predict the timing of forestry measures in order to maintain the openwork design of forest belts recommended for the region under study.

Особенности эксплуатации лесовозных дорог в весенне-зимний период

Seasonal roads are not capital construction objects. Unlike all-season ones, they can be of summer and winter action. During the transport development of forests, both allseason paved roads and temporary unpaved roads are required. The share of temporary roads is more than 90 % of all logging roads. One of the main problems of temporary logging roads is uneven seasonal operation, especially in summer. Seasonal roads do not have a permanent surface; more often it is natural soil, subject, except for mechanical impacts, to atmospheric ones, which is most evident in the summer-autumn period. Therefore, about 80 % of the harvested wood is exported via winter roads. The density of temporary roads depends on the general harvesting technology in a particular area, including the wood skidding distance and the angle of relative position of forest roads. Winter road construction works are carried out in summer and winter. In summer, engineering surveys are carried out, the optimal direction of the future route is determined, a clearing is cut, a roadbed is prepared, and if necessary, culverts are installed. With the onset of cold weather, the existing soil is compacted and leveled to accelerate its freezing. If the roadbed is sufficiently frozen, a snow-ice cover is formed. The article considers the influence of roadside forest plantations on the air temperature near the road surface, soil temperature, blocking solar radiation – the factors that are directly related to the overall service life of a winter road. Special attention is paid to slowing down the decrease in the winter road pavement strength in the shade of preserved trees by choosing the optimal route direction. The slowdown in the decrease in the pavement strength of the forest dirt road has been established and confirmed in areas where solar radiation is blocked by trees, i.e. in the shade. The difference in strength reduction to the minimum is 33 days. Based on the research results, it has been concluded that a comprehensive development of the logistics strategy for the organization of roundwood transportation via winter roads is necessary.

Multitemporal monitoring of paramos as critical water sources in Central Colombia

Paramos, unique and biodiverse ecosystems found solely in the high mountain regions of the tropics, are under threat. Despite their crucial role as primary water sources and significant carbon repositories in Colombia, they are deteriorating rapidly and garner less attention than other vulnerable ecosystems like the Amazon rainforest. Their fertile soil and unique climate make them prime locations for agriculture and cattle grazing, often coinciding with economically critical deposits such as coal which has led to a steady decline in paramo area. Anthropic impact was evaluated using multispectral images from Landsat and Sentinel over 37 years, on the Guerrero and Rabanal paramos in central Colombia which have experienced rapid expansion of mining and agriculture. Our analysis revealed that since 1984, the Rabanal and Guerrero paramos have lost 47.96% and 59.96% of their native vegetation respectively, replaced primarily by crops, pastures, and planted forests. We detected alterations in the spectral signatures of native vegetation near coal coking ovens, indicating a deterioration of paramo health and potential impact on ecosystem services. Consequently, human activity is reducing the extent of paramos and their efficiency as water sources and carbon sinks, potentially leading to severe regional and even global consequences.

Variations in the Forest Productivity of Pinus patula Plantations in Tanzania: The Need for an Improved Site Classification System

The productivity of forests in sub-Saharan Africa is often summarized into large compartments or site classes. However, the classification of forest productivity levels based on the original site index model in Tanzania and the techniques applied to generate the model did not include the micro-toposequence variations within compartments. This may create false expectations of wood supply and hinder the estimation of sustainable harvesting processes. This study analyzed variations in forest productivity and the site index in P. patula stands in two forest plantations of Tanzania to assess the applicability and generality of the present site classification system. We used dominant height as a proxy for forest productivity in 48 plots at the Sao Hill forest plantation (SHFP) and 24 plots at the Shume forest plantation (SFP). We stratified the sampling plots in each site class along the soil catena and recorded the elevation, slope, and slope positions (summit, mid, and lower). Our results showed that the site classes did not generally match the previously assigned site classes and the productivity of a given site class varied between the two plantations. We found a consistently higher productivity than that implied by the original site index in SFP, while in SHFP, the productivity was both higher and lower than estimated in different compartments. Both elevations and slope significantly contributed to predicting the productivity variations within site classes. Overall, the results indicate that physiographic factors affect variations in forest productivity within the assigned site classes. We recommend a more comprehensive site productivity assessment that takes into account physiographic variations and hence provides more accurate information for sustainable forest plantation management in Tanzania and in the region at large.

Carbon‐Water Tradeoffs in Old‐Growth and Young Forests of the Pacific Northwest

AbstractDespite much interest in relationships among carbon and water in forests, few studies assess how carbon accumulation scales with water use in forested watersheds with varied histories. This study quantified tree growth, water use efficiency, and carbon‐water tradeoffs of young versus mature/old‐growth forest in three small (13–22 ha) watersheds in the H.J. Andrews Experimental Forest, Oregon, USA. To quantify and scale carbon‐water tradeoffs from trees to watersheds, tree‐ring records and greenness and wetness indices from remote sensing were combined with long‐term vegetation, climate, and streamflow data from young forest watersheds (trees ∼45 years of age) and from a mature/old‐growth forest watershed (trees 150–500 years of age). Biomass production was closely related to water use; water use efficiency (basal area increment per unit of evapotranspiration) was lower; and carbon‐water tradeoffs were steeper in young forest plantations compared with old‐growth forest for which the tree growth record begins in the 1850s. Greenness and wetness indices from Landsat imagery were not significant predictors of streamflow or tree growth over the period 1984 to 2017, and soil C and N did not differ significantly among watersheds. Multiple lines of evidence show that mature and old‐growth forest watersheds store and accumulate more carbon, are more drought resistant, and better sustain water availability compared to young forests. These results provide a basis for reconstructions and predictions that are potentially broadly applicable, because first‐order watersheds occupy 80%–90% of large river basins and study watersheds are representative of forest history in the Pacific Northwest region.