Secondary Forest Research Articles

“A quantitative analysis on the adoption of soil, water, and forest conservation technologies in the upper Gelana watershed, Northeast Ethiopian highlands”

Globally, the degradation of soil, water, and forests has had a significant impact on both livelihoods and the environment. This issue is particularly severe in developing countries, including Ethiopia. Despite extensive efforts to implement conservation measures for soil, water, and forests in the highlands of Ethiopia, there has been a lack of thorough evaluation and documentation regarding the adoption of these practices by rural households. It is crucial to have scientific and up-to-date information at various spatial scales in order to effectively monitor existing practices, scale up successful initiatives, and promote sustainable regional development. Therefore, this paper focuses on analyzing the adoption of soil, water, and forest conservation activities by households in the upper Gelana watershed, South Wollo zone, Amhara Regional State of Ethiopia. The field data collection for this study took place from January to March 2022, from 150 rural household heads. Data analysis was carried out using SPSS software version 23. Descriptive statistics, Pearson bivariate correlation, and multinomial logistic regression were used. The survey findings revealed that 69 % of the respondents had implemented various soil, water, and forest conservation measures at different stages. The Pearson correlation results indicated a positive relationship between the adoption of soil, water and forest conservation practices. The multinomial logistic regression analysis has revealed that age, gender, access to credit, and access to extension services, significantly influenced the households’ decision behaviour to adopt soil conservation practices. Age, access to extension service, and access to water resource were significant predictors of adoption of water conservation practices; whereas age, educational status, and access to extension service were significant predictors of adoption of forest conservation practices. This study underscores the significance of institutional factors in driving the adoption of technology in the research area. It further recommends policies that prioritize the dissemination of information on effective strategies, improvement of access to extension services, water resources, and credit facilities to promote sustainable watershed management. This study is exceptional in its innovative approach, which explores the convergence of these vital conservation domains within the distinct setting of the upper Gelana watershed. Studying the adoption of these technologies is crucial for informing policy-making and designing effective interventions that promote sustainable watershed practices. In this case, the Ministry of Agriculture, and development agents should scale up the adoption of these practices and take remedial actions for those not yet adopted.

Spatial Pattern of Living Woody and Coarse Woody Debris in Warm-Temperate Broad-Leaved Secondary Forest in North China.

The investigation into the spatial distribution of living woody (LWD) and coarse woody debris (CWD) within forests represents a fundamental methodology for probing the inherent mechanisms governing coexistence and mortality within forest ecosystems. Here, a complete spatial randomness (CSR) null model was employed to scrutinize the spatial pattern, while canonical correspondence analysis (CCA) and the Torus-translation test (TTT) were utilized to elucidate the distribution patterns of LWD and CWD within warm-temperate deciduous broadleaf secondary forests in Dongling Mountains plot, northern China. The results reveal that both LWD and CWD exhibit an aggregated distribution as the predominant pattern in the Dongling Mountains plot, with the proportion and intensity of aggregation diminishing as spatial scale increases. Specifically, the aggregation intensity g0-10 demonstrates a significant negative correlation with abundance and maximum diameter at breast height (DBH). Notably, the g0-10 of LWD manifests a stronger correlation with the maximum DBH, whereas the g0-10 of CWD exhibits a greater association with the mortality rate. CCA outcomes suggest that elevation, convexity, and aspect significantly impact LWD distribution, whereas CWD distribution shows substantial negative correlations with elevation, convexity, slope, and aspect. TTT findings indicate that ecosystems characterized by a substantial presence of LWD also display a notable prevalence of CWD. Additionally, the majority of species exhibit no habitat preference, displaying neutral habitat connections and low ecological niche differentiation within the sampled plot.

The relative importance of local versus regional habitat structure variation on the abundance of two generalist mutualists along a forest disturbance gradient

Mutualistic interactions are key to biodiversity generation and maintenance, being pollination and seed dispersal interactions essential for plant reproduction. However, anthropogenic habitat disturbance can alter these interactions. We studied the regional and local effects of habitat disturbance on two generalist mutualist animals of southern Chile temperate rainforests: the hummingbird Sephanoides sephaniodes and the marsupial Dromiciops gliroides, which perform key roles as pollinator and seed disperser, respectively. We sampled 12 sites corresponding to four disturbance conditions (mature native forest, secondary forest, native forest under selective logging, and exotic forest plantations) in which we estimated the number of S. sephaniodes and D. gliroides records (as a proxy of relative abundance) using camera traps. We measured seven habitat structure variables at each site, known to influence their occurrence. Specifically, we examined S. sephaniodes and D. gliroides abundance variation at (i) a regional scale (among disturbance conditions) and (ii) at a local scale (among sampling sites). Dromiciops gliroides abundance decreased as disturbance increased, but S. sephaniodes abundance was highly variable. At the local scale, S. sephaniodes and D. gliroides abundances were largely variable among sites, influenced by habitat structural features, such as bamboo and shrub cover and woody debris. Our results show that although habitat disturbance may influence mutualist abundances, they can tolerate disturbance if minimum structure and resource requirements are met, but respond idiosyncratically to local conditions. Examining local-scale variability may provide valuable information on ecological processes, which often goes unnoticed when local sites are considered as replicates in landscape-level studies.

Primary forests harbour more bird taxonomic, phylogenetic and functional diversity than secondary and plantation forests in the pantropics

Primary forests harbour more bird taxonomic, phylogenetic and functional diversity than secondary and plantation forests in the pantropics

Interpretation of Soil Characteristics and Preferential Water Flow in Different Forest Covers of Karst Areas of China

Soil hydrology seriously affects the prevention of desertification in karst areas. However, water infiltration in the different soil layers of secondary forests and artificial forests in karst areas remains uncertain. This lack of clarity is also the factor that constrains local vegetation restoration. Therefore, monitoring and simulating the priority transport of soil moisture will help us understand the shallow soil moisture transport patterns after artificial vegetation restoration in the local area, providing a reference for more scientific restoration of the ecological environment and enhancement of carbon storage in karst areas. The integration of soil physical property assessments, computed tomography (CT) scanning, dye tracing studies, and HYDRUS-2D modeling was utilized to evaluate and contrast the attributes of soil macropores and the phenomenon of preferential flow across various forestland categories. This approach allowed for a comprehensive analysis of how the soil structure and water movement are influenced by different forest ecosystems and infiltration head simulations (5 mm, 15 mm, 35 mm, and 55 mm) to elucidate the dynamics of water movement across diverse soil types within karst regions, to identify the causes of water leakage due to preferential flow in secondary forests, and to understand the mechanisms of water conservation and reduction in artificial forests adopting a multifaceted approach. This study demonstrated that (1) the soil hydrological capacity of a plantation forest was 20% higher than a natural forest, which may be promoted by the clay content and distribution. (2) Afforestation-enhanced soils in karst regions demonstrate a significant capacity to mitigate the loss of clay particles during episodes of preferential flow and then improve the soil erosion resistance by about 5 times, which can effectively control desertification in karst area. (3) The uniform distribution of macropores in plantation forest soil was conducive to prevent water leakage more effectively than the secondary forest but was incapable of hindering the occurrence of preferential flow. The secondary forest had a very developed preferential flow phenomenon, and soil clay deposition occurred with an increase in depth. (4) Moreover, the results for preferential flow showed that the matrix flow depth did not increase with the increase in water quantity. Short-term and high-intensity heavy rainfall events facilitated the occurrence of preferential flow. Infiltration along the horizontal and vertical directions occurred simultaneously. These results could facilitate a further understanding of the contribution of the plantation to soil amelioration and the prevention of desertification in karst areas, and provide some suggestions for the sustainable development of forestry in karst areas where plantation restoration is an important ingredient.

Nitrogen and phosphorus uptake dynamics in anthropized and conserved Caatinga dry forests

Understanding human impacts on drylands is crucial in a global scenario of forest degradation and biodiversity loss. This study analyzed foliar concentrations of nitrogen (N) and phosphorous (P) in the Brazilian seasonally dry tropical forests (Caatinga). Foliar patterns of N, P, and the N/P ratio were assessed both within and among botanical families. To do this, 10 plots were established in an anthropized area and 10 in a conserved area. Within each plot, leaves from all tree species and soil samples from four random points were collected. Stoichiometric analyses were performed on the leaves of 136 trees from 14 botanical families. Significant differences were observed in soil P concentrations, organic matter content, and cation exchange capacity, with the highest values found in the conserved area. Foliar N and P concentrations and N/P were also higher in the conserved area for the F+ (nitrogen-fixing Fabaceae), F- (non-nitrogen-fixing Fabaceae), and NF (non-Fabaceae) groups, indicating greater efficiency in nutrient retention and cycling. When comparing species found in both areas, Aspidosperma pyrifolium (NF), Bauhinia forficata (F-), and Mimosa ophthalmocentra (F+) showed significant differences in foliar N concentrations and foliar P (for A. pyrifolium and B. forficata only). Degradation of the Caatinga directly impacts nutrient cycling.

Dynamics of structural indices and organic carbon pool across a haplic acrisol under secondary tropical rainforest at Umudike Abia State

Differences in vegetation types over a landscape influences the structural behaviour and organic carbon pool of soils thereby affecting site-specific management decisions. This study aimed at establishing the differences in structural indices and organic carbon pool across a soil under secondary rainforest vegetation. Nine replicates of auger and core soil samples were randomly collected from the site at 0 – 20 cm depth. Soil samples were prepared and analysed at a laboratory. Data obtained were subjected to geospatial analysis using a Geographical Information System (GIS) software package. Results showed that changes in organic carbon storage ranged from 40 – 48 ton / ha, BD ranged from 1.39 – 1.42 mg / m3, clay flocculation index ranged from 50 – 68 %, aggregated silt + clay ranged from 9 – 12 %, clay dispersion index ranged from 32 – 42 %, dispersion ratio ranged from 26 – 32 %, mean weight diameter ranged from 0.75 – 1.05 mm, saturated hydraulic conductivity ranged from 3.1 – 3.8 cm / mins and total porosity ranged from 46.4 – 47.6 %. Regions of weak micro aggregaion dominated the land while regions of increased stability of macro aggregates were dominant. Regions of increased soil organic carbon storage occupied about half portion of the land. Greater portion of the land was noted for increased bulk density, reduced total porosity and saturated hydraulic conductivity. Consequently, there were changes in soil structural properties and organic carbon storage across the studied area.

Determinants of carbon sequestration in thinned forests

Given global climate change and the projected increases in the greenhouse effect, enhancing the carbon storage capacity of forest ecosystems is especially critical. To fully realize the potential carbon sequestration, it is imperative to understand the drivers affecting carbon storage in forest ecosystems, particularly with disturbances that disrupt existing balance. In this study, we explored the effects of stem-only harvest at various thinning intensities on forest structure and carbon density in middle-aged natural secondary forests, located in the northern temperate zone. Carbon density included aboveground carbon density (ACD), soil organic carbon stocks (SOCD), and total carbon density (TCD), which was the sum of ACD and SOCD. We employed the random forest analysis method to identify significant variables influencing changes in carbon density. Structural equation modelling (SEM) was then used to determine the drivers of changes in forest carbon density. The results showed that moderate thinning (20 %–35 % trees removed), is an effective management practice for increasing the TCD in forests. Although heavy thinning (35.1 %–59.9 % trees removed) accelerated individual growth, it did not fully offset the carbon removed due to thinning. It is noteworthy that light thinning (0–19.9 % trees removed) not only reduced the species richness but also caused a significant number of tree deaths. Large live trees were an important direct determining factor of ACD, but not the only one. In addition, thinning indirectly influenced ACD by reducing canopy density and deformed tree density. The increase in dead tree density had an adverse impact on SOCD, and this phenomenon increased with the passage of recovery time. Conversely, greater thinning intensity enhanced SOCD. Moreover, TCD was directly influenced by tree height, large live trees, and stand density. Furthermore, thinning altered the conifer ratio, thereby influencing tree growth and indirectly controlling the TCD. We believe that this knowledge will be highly beneficial for successful forest management and enhancing the carbon sequestration capacity of forest ecosystems.

Population and Habitat Characteristics of Tarsius fuscus in Resort Mallawa Bantimurung Bulusaraung, South Sulawesi

Tarsius fuscus is one of the conservation priority wildlife in the Bantimurung Bulusaraung National Park (Babul National Park). This study aims to analyze the population and habitat characteristics of T. fuscus as one of the considerations in the conservation management of its population and habitat. This research was carried out in July 2021 in the forest around Bentenge Village and Samaenre Village, Resort Mallawa, Babul National Park. The method used was direct observation, calculation of the number of individuals for each group, and vegetation analysis at the meeting points of T. fuscus. Based on observations, the population size of 48 individuals from 13 groups was obtained with an overall population density of 0.109 individuals/Ha. The population density in the secondary dryland forest is higher than in the scrubland. The number of juvenile and infant in both land cover were low compared to the adults. T. fuscus was found in two types of habitat, there are secondary dryland forests (SDF) and scrubland with specific ranges of physical parameters. Based on vegetation analysis, SDF was dominated by the mana-mana tree (Blumeodendron kurzii) with an important value index (IVI) of 57.72%, while shrubland was dominated by kemiri tree (Aleurites moluccana) with an IVI of 40.75%. The two land covers are dominated by the Moraceae family and jambu air seedlings (Syzygium aqueum).

Individual tree diameter growth modelling for natural secondary forest in Changbai Mountains, Northeast China

Individual modelling is a foundational approach to study the natural forest growth and in this paper, we develop a serial distance-depended individual tree model for some species in natural forest which would provide prediction and characteristics for natural species. The data used to develop individual model for natural mixed forests were collected from 712 remeasured 10-year periodic permanent sample plots of in Baihe Forest Bureau of Changbai Mountains, northeast China. Based on analyzing relationship between diameter increment of individual trees with tree size, competitive status, and site condition and finding out the major independent variables, the growth models for individual trees of 15 species in the natural mixed forests, that have good predicting precision, and easily applicable, were developed using stepwise regression method. The individual growth model developed in this study can reflect the tree increment of 15 species and be generally well suited for simulating tree and stand growth for natural mixed forests in Changbai Mountains. The research results for individual trees growth model of each species showed that main variable to influence on diameter increment of individual trees for natural mixed forests were tree size (D) and then competition index. The site condition was not related with diameter increment. The natural logarithm of DBH (lnD) and square diameter (D2) were included in the predicting models of diameter increment for all 15 species. The diameter increment was directly proportional to tree diameter for each species. For the competitive indexes in growth model, the relative diameter (RD), canopy closure (P), and the ratio of diameter of subject tree with maximum diameter (DDM) were related to diameter increment and the stand density measures were not significantly influenced on diameter increment. As canopy closure increase, tree increment decreases. The site conditions were performance less of factors in increment predictions in the model.

Degradation-driven vegetation-soil-microbe interactions alter microbial carbon use efficiency in Moso bamboo forests

Microbial carbon utilization efficiency (CUE) is a crucial indicator for evaluating the efficiency of soil carbon sequestration and transformation, which is applied to quantify the proportion of soil carbon extracted by microbes for anabolism (growth) and catabolism (respiration). Previous studies have shown that the degradation of Moso bamboo forests (Phyllostachys edulis) destroyed the aboveground bamboo structure, reduced vegetation carbon storage, and weakened ecosystem carbon sequestration capacity. Interestingly, soil organic carbon stocks are gradually increasing. However, the mechanism by which degradation-induced changes in soil and vegetation characteristics affect microbial CUE and drive soil carbon sequestration remains unclear. Here we selected four stands with the same origin but different degradation years (intensive management, CK; 2 years' degradation, DM1; 6 years' degradation, DM2; and 10 years' degradation, DM3) based on the local management profiles. The principle of space-for-time substitution was used to investigate the changes in microbial CUE along a degradation time and to further identify the controlling biotic and abiotic factors. Our finding showed that microbial CUE increased by 12.27 %, 31.01 %, and 55.95 %, respectively, compared with CK; whereas microbial biomass turnover time decreased from 23.99 ± 1.11 to 17.16 ± 1.20 days. Promoting microbial growth was the main pathway to enhance microbial CUE. Massive inputs of vegetative carbon replenished soil carbon substrate content, and altered microbial communities and life history strategy, which in turn promoted microbial growth and increased microbial CUE. These findings provide theoretical support for the interactions between carbon dynamics and microbial physiology in degraded bamboo forests, and reinforce the importance of vegetation and microbial properties and soil carbon substrates in predicting microbial CUE.

Ecological succession shapes size–density scaling relationships of trees and soil invertebrates

Abstract The widely observed negative scaling relationship between organism size and abundance is predicted to have a universal −0.75 scaling exponent across all life forms. However, factors influencing frequently observed deviations from this exponent, such as ecosystem succession and organism traits, remain poorly understood. We explore the dependence of size–density scaling on ecosystem succession and organism traits by analysing size–density relationships in trees and soil invertebrates across 183 temperate forest plots comprising urban secondary forests, urban old‐growth forests and non‐urban natural forests. Exponents of scaling relationships in urban tree and invertebrate communities progressively steepened with increasing restored (planted) forest stand age as small organisms increased in abundance. In contrast, non‐urban tree scaling relationships flattened during succession with exponents veering away from −0.75, whereas urban tree and invertebrate communities converged towards this prediction in later successional stages. Our results shed light on how the body size structure of tree and soil invertebrate communities spanning multiple trophic levels shift over successional time as the relative abundances of large versus small‐bodied organisms increase. This study emphasises the fundamental influence of organismal traits and ecosystem succession on scaling relationships of organism body size and abundance. Read the free Plain Language Summary for this article on the Journal blog.

New records for the flora of Niue: Crepidomanes saxifragoides (C.Presl) P.S.Green (Hymenophyllaceae), Erigeron bellioides DC. (Asteraceae) and Psidium cattleyanum Sabine (Myrtaceae)

ABSTRACT Recent field surveys of the flora of Niue have identified three new species records for the island. Erigeron bellioides DC. (Asteraceae) and Psidium cattleyanum Sabine (Myrtaceae) are new naturalised records and Crepidomanes saxifragoides (C.Presl) P.S.Green (Hymenophyllaceae) is an addition to the indigenous flora. Crepidomanes is a new genus for the indigenous flora of Niue. Information is provided for each of these species on their biostatus, collections, distribution and habitats. Erigeron bellioides is known from several locations that provide access to sea and chasm walks where it mostly occupies disturbed and grassy habitats used for car parks. It is most probably being spread by seeds adhering to tourists’ footwear and vehicle tyres as they move between popular attractions. In contrast, Psidium cattleyanum is known from a single plant on the margin of regenerating secondary forest along the Puluhiki Sea Track (Lakepa). It is unlikely to have been planted at this site and may be cultivated in the nearby Lakepa village, which could be the seed source for the established wild plant. Psidium cattleyanum is an invasive species on other Pacific Islands and we recommend removal of the single known plant and survey for it elsewhere, including gardens of the villages. Crepidomanes saxifragoides is known from a single collection in primary forest of the Huvalu Forest Conservation Area where it grew on the shaded and moist surface of a root buttress at the base of a trunk of Syzygium.

DISTRIBUTION OF THE THALLOID LIVERWORT GENUS MARCHANTIA (MARCHANTIACEAE) IN NORTH SUMATRA, INDONESIA

ARTICLE HIGLIGHTS- The survey method was successful in identifying the species Marchantia and mapping their distribution in North Sumatra- Eight taxa of Marchantia confirmed in North Sumatra, M. emarginata subsp. cuneiloba has the most widely distributed species. - Species distribution linked to environmental factors like elevation, humidity, rainfall, soil types, slope, solar intensity, and types of land coverABSTRACTMarchantia is one of the large genus complex thalloid liverworts (Marchantiophyta). The species of Marchantia has a wide distribution throughout the world, and occupies a variety of substrates. Studies on the presence and distribution of Marchantia species are still limited in North Sumatra. Therefore, the research was carried out to inventory the species of Marchantia and map their distribution in North Sumatra. Survey method was used to inventory the species of Marchantia, covering 9 locations, namely: Aek Nauli Forest, Bukit Barisan National Forest Park, Bukit Lawang, Resort Cinta Raja, Dolok Tinggi Raja Nature Reserve, Sibayak Mountain, Sicike-cike Natural Park, Silima-lima waterfall, and Taman Eden 100 Natural Park. Geographic Information System (GIS) was used to map the distribution of the species. The results showed that there were eight taxa of Marchantia confirmed in North Sumatra, namely, M. acaulis, M. emarginata subsp. emarginata, M. emarginata subsp. cuneiloba, M. geminata, M. paleacea subsp. paleacea, M. polymorpha, M. treubii, and Marchantia sp. The most widely distributed species of Marchantia is M. emarginata subsp. cuneiloba, found in 7 study locations. Species with the least distribution are M. treubii and Marchantia sp., each species found only in one location. Marchantia spp. in North Sumatra spread at an altitude of 77 to 1976 m alt, occupying habitats with 6 types of soil (orthic acrisol, humic andosol, humic acrisol, and humic cambisol), with rainfall of 1800-3600 mm/year. Marchantia species are found on sloping plains to steep, in various habitat, namely secondary forest, primary and secondary forest borders, dryland farming, primary and plantation borders, and plantations. The results of this study are important for the conservation of Marchantia spp. in North Sumatra considering the many benefits of the species.

Orchid species diversity across a forest disturbance gradient in west Mau forest, Kenya.

Orchidaceae is one of the most diverse and widespread groups of flowering plants. Despite their immense ecological and socio-economic value, their spatial distribution across forest disturbance gradient is not well understood, particularly in tropical montane forests. This study assessed the influence of forest degradation on orchid species richness and abundance in West Mau Forest, Kenya. Stratified systematic sampling was adopted across three different disturbance regimes consisting of relatively intact forest, moderately disturbed forest and highly degraded forest. A total of five orchid species were recorded from nine host-tree species. The intact forest had seven host tree species with five orchid species. The moderately degraded forest had four host-tree species with two orchid species, while the highly degraded forest that had no orchids. Polystachya confusa was the most abundant orchid species (600.0±227.9 clumps ha-1) followed by Bulbophyllum sp (340.0±112.2 clumps ha-1), Chamaeangis sp (300.0±115.5 clumps ha-1), Aerangis sp (200.0±57.7 clumps ha-1) and Tridactyle sp (100.0±0.0 clumps ha-1). The results of this study indicate that forest degradation reduces orchid species diversity in tropical montane forests. They also show that orchids are bioindicators of forest degradation status.

Identification of Harbin Ecological Function Degradation Areas Based on Ecological Importance Assessment and Ecological Sensitivity

This study is based on the National Spatial Ecological Protection and Restoration Plan, using logical ecological evaluation indicators to determine the extent of ecological function degradation areas in Harbin City. In the Heilongjiang Province, Harbin faces severe ecological environment degradation, characterized by reduced area, deteriorated water quality, loss of biodiversity, and water resource competition. Identifying degraded ecological regions can effectively address these environmental issues. A multi-level indicator system was constructed to evaluate and identify ecological important and sensitive areas across the city, followed by integrating these results to delineate various levels and types of ecological protection and restoration zones in Harbin. Results indicate that these zones include ecological priority protection areas such as marshes surrounding the Harbin section of the Songhua River, southern aquatic wetlands, and scattered forest conservation areas. Key ecological restoration areas are found in the eastern urban core of Harbin, as well as in Bayan County, Bin County’s northern region, Wuchang City’s northwest region, and Yilan County. General ecological restoration areas are primarily distributed in Songbei District, Shuangcheng District, Mulan County, southeastern Bin County, Shangzhi City, southeastern Wuchang City, and some surrounding counties along the Songhua River. Priority ecological protection areas consist mainly of unused land, cultivated land, and forests, while key and general ecological restoration areas are predominantly composed of cultivated land and forests respectively.

Eucalyptus essential oils: chemical profiling and pharmacological potential for sustainable forest cultivation

Eucalyptus essential oils: chemical profiling and pharmacological potential for sustainable forest cultivation

A large net carbon loss attributed to anthropogenic and natural disturbances in the Amazon Arc of Deforestation

The Amazon forest contains globally important carbon stocks, but in recent years, atmospheric measurements suggest that it has been releasing more carbon than it has absorbed because of deforestation and forest degradation. Accurately attributing the sources of carbon loss to forest degradation and natural disturbances remains a challenge because of the difficulty of classifying disturbances and simultaneously estimating carbon changes. We used a unique, randomized, repeated, very high-resolution airborne laser scanning survey to provide a direct, detailed, and high-resolution partitioning of aboveground carbon gains and losses in the Brazilian Arc of Deforestation. Our analysis revealed that disturbances directly attributed to human activity impacted 4.2% of the survey area while windthrows and other disturbances affected 2.7% and 14.7%, respectively. Extrapolating the lidar-based statistics to the study area (544,300 km2), we found that 24.1, 24.2, and 14.5 Tg C y-1 were lost through clearing, fires, and logging, respectively. The losses due to large windthrows (21.5 Tg C y-1) and other disturbances (50.3 Tg C y-1) were partially counterbalanced by forest growth (44.1 Tg C y-1). Our high-resolution estimates demonstrated a greater loss of carbon through forest degradation than through deforestation and a net loss of carbon of 90.5 ± 16.6 Tg C y-1 for the study region attributable to both anthropogenic and natural processes. This study highlights the role of forest degradation in the carbon balance for this critical region in the Earth system.

Effect of anthropogenic activities on carbon stocks in protected areas within Ghana's forest-Savannah transition zone

Tropical forests play a significant role in climate change by sequestering atmospheric carbon dioxide. However, deforestation and forest degradation adversely affect these forests’ carbon stocks. Reports indicate that anthropogenic activities have led to forest degradation and deforestation in Boabeng Fiema Monkey Sanctuary (BFMS) and Kogyae Strict Nature Reserve (KSNR). This study assessed the effects of these activities on the carbon stocks of BFMS and KSNR. Using satellite imagery, field measurements and allometric models, carbon stocks of the study area were assessed from 1992 to 2023. The assessment revealed significant losses attributed to anthropogenic activities, such as hunting, farming and charcoal burning. BFMS experienced a total loss of 40,236 Mg C, while KSNR lost 272,109 Mg C. The closed forests had the highest carbon stock amongst the different vegetation types, with soil representing the most significant carbon pool in the protected areas, revealing the influence of vegetation structure on carbon sequestration and the need for soil conservation. The substantial carbon sequestration potential observed in the different vegetation types of the study area indicates that the Forest-Savannah Transition Zone is a prospective area for climate change mitigation aligning with the Sustainable Development Goals (Goals 13 and 15) and the National Climate Change Policy of Ghana. These findings provide valuable insights for carbon trading and biodiversity conservation, emphasizing the potential of nature-based solutions in addressing global climate challenges.

Fire is associated with forest degradation and economic land concessions, but not land conversion in the rapidly transforming Cambodian landscape

Abstract Cambodia is beset by high deforestation rates and fire frequencies. From 2001–2020, forest cover declined by 34%, and cropland and rubber expanded by 31,401 km2 and 4,530 km2, respectively; meanwhile nearly 8.7 million fires burned 41.6% of the land. Fires may be associated with deliberate land change, stable land management systems, and unplanned forest degradation. We integrated annual land cover and monthly burned area data from 2001–2020 to test three hypotheses. First, if fire is used during land conversion, there would be a detectable pulse in fire activity in the year immediately prior to, and the year of land cover change. Our temporal analysis found statistically elevated burn rates in five of 16 transition tests, however, they were typically <1% outside the predicted range, indicating no practical significance in the association of fire with land cover change. Second, fire prevalence would be lower in land managed for conservation or agricultural production than unclassified or unmanaged land. persistent forest and shrubland burned at significantly higher rates than expected, cropland burned significantly less, burning was almost absent from rubber plantations, and forests in protected areas (PAs) exhibited lower total burn percentages than unclassified land or industrial economic land concessions (ELCs), thus supporting the fire-land management hypothesis. However, total burned area in ELCs was greater than unclassified land for several persistent land cover classes, suggesting that local landowners may prevent fire in commercially valuable private agricultural land, but there may be no such prevention measures in industrial ELCs. Anti-fire policy enforcement in ELCs should be enhanced. Third, forests that converted into (degraded) shrublands would experience increasing fire frequency in the years leading up to transition, a hypothesis we found strong support for through our temporal analysis. Cambodia’s 2013 Law on Fire Prevention and Fire Fighting deputizes the public to enforce its provision, however given that the vast majority of fires occur in persistent forest in state-owned land, collective action problems are likely to hinder its effective implementation.