Natural Forest Systems Research Articles

Exploring Genetic Diversity and Variability of Tamarind (Tamarindus indica L.): A Comprehensive Study in the Bilaspur Region of Chhattisgarh, India

The genetic diversity and variability of Tamarindus indica L., a valuable multipurpose tree species, was investigated through a comprehensive study conducted in the Bilaspur region. This research aimed to assess the morphological variations and growth responses of T. indica under contrasting environments, specifically agroforestry and natural forest systems. The study employed a rigorous scientific approach, encompassing field surveys, statistical analyses, and morphological assessments. The results indicated pronounced morphological differences between T. indica trees in the agroforestry and natural forest systems. T. indica trees in the natural forest exhibited significantly greater average height and diameter at the breast height (DBH) compared to those in agroforestry settings, highlighting the influence of the environment on growth parameters. Here, the crown diameter displayed homogeneity across both environments, suggesting a potential level of adaptability in this trait. The findings show the importance of considering environmental conditions when assessing the growth and development of T. indica, providing valuable insights for both scientific research and practical applications in agroforestry and conservation efforts.

Untangling the effect that replacing Ethiopia's natural forests with exotic tree plantations has on arbuscular mycorrhizal fungi

Arbuscular mycorrhizal fungi (AMF) have a broad distribution and establish symbiotic relationships with vascular plants in tropical regions. They play a crucial role in enhancing plant nutrient absorption, mitigating pathogenic infections, and boosting the resilience of host plants to abiotic stresses, including drought under specific conditions. Many natural forests in Ethiopia are being replaced by monospecific plantations. However, the impact of these actions on AMF is unknown and, despite their ecological functions, AMF communities in various forest systems have not been thoroughly investigated. In this study, we assessed soil AMF communities in natural and plantation forests by DNA metabarcoding of the ITS2 rDNA region and assessed the influence of climate and environmental variables on the AMF community. In total, 193 AMF operational taxonomic units (OTUs), comprising nine families and 15 genera, were recorded. Glomerales was the dominant order (67.9 % of AMF OTUs) and Septoglomus fuscum, Diversispora insculpta, and Funneliformis mosseae were the dominant species. AMF were more abundant in natural forests than in plantation forests and the composition of AMF communities differed significantly from those of plantation forest. In plantation forests, soil pH, organic carbon, total nitrogen, and available phosphorus significantly influenced the composition of AMF communities, whereas in natural forest, electrical conductivity, annual rainfall, and cumulative rainfall before sample collection were significantly correlated with AMF. SIMPER analysis identified the AMF responsible for composition variances among different forest types, with the Glomeraceae family being the most significant contributor, accounting for nearly 60 % of the dissimilarity. Our findings further our understanding of the ecological niche function and the role of AMF in Ethiopia's natural forest systems and highlight the importance of prioritizing the sustainable development of degraded natural forests rather than plantations to ensure the preservation of habitats conducive to maintaining various AMF communities when devising conservation and management strategies.

Taxonomic and functional composition of arthropod assemblages across contrasting three different land use systems

Soil microarthropods play a crucial role in agricultural ecosystems and are necessary for the upkeep of fertile and productive soils. Limited knowledge exists regarding the composition of soil microarthropod communities in changing agricultural and impervious land use systems. Hence, we conducted a comparative analysis of the soil microarthropod diversity in shifting cultivation and impervious land areas, as well as the surrounding natural forest ecosystem in Aizawl, Mizoram, northeast India. Additionally, we evaluated the influence of shifting cultivation and impervious land use regimes on the diversity of these microarthropods. The investigation was done between 2022 and 2023. Soil and litter samples (n=50) were gathered from three distinct land use systems. The soil microarthropods were extracted using the Berlese funnel method. Microarthropod taxa were identified down to the most specific taxonomic level feasible. The variety of soil microarthropods was significantly affected by the practice of shifting cultivation and in the impervious land areas, in comparison to the natural forest system. The soil chemical profiles were notably altered in the shifting agriculture and impermeable land use systems, indicating their detrimental effects on soil microarthropod diversity. This study presented the startling information on the diversity of soil microarthropods and their relationship with the land-use systems in Mizoram, a region in northeast India.

Examining the Shift in the Decomposition Channel Structure of the Soil Decomposer Food Web: A Methods Comparison.

Selecting the appropriate indicators and measuring time point numbers is important for accurately examining the shift in soil gross decomposition channel structure. Through a selected case study on a natural forest vs. rainfed arable system over a two-month-long experiment, the utility of three commonly employed indicators (fungi to bacteria ratio (F:B), fungivore to bacterivore ratio (FF:BF), and glucosamine to muramic acid ratio (GlcN:MurN)) were compared to reflect the shift in soil gross decomposition channel structure. The requirement of measuring the time point numbers for the three indicators was also assessed, and we suggest a potential methodology. Our results revealed that the GlcN:MurN ratio was more reliable for assessing the shifts in gross decomposition channel structure for long-term land use changes, while it was less sensitive to short-term drought compared with the other two indicators. The F:B ratio was more applicable than the FF:BF ratio for reflecting both long- and short-term changes. Furthermore, the reliability of the GlcN:MurN ratio was the least dependent on measuring time point numbers. We suggest the use of multiple indicators and the adoption of multiple measuring time points for the overall methodology.

Taxonomy and genesis of soils in contrasting ecosystems of Southern Western Ghats, India

Clay minerals formed during soil formation are imprints of ecosystem functioning and pedogenic processes in landscapes. The study evaluated the variations in taxonomy, soil weathering and pedogenic changes in contrasting forest soils in the Southern Western Ghats, India. Three different forest systems with comparable soil-forming factors vis-a-vis evergreen, moist deciduous and a man-made system (rubber plantation) were evaluated for physical, chemical, morphological, and pedogenic characteristics of the related soils. Soil profiles were dug up to 1.50 m in the selected ecosystems and horizon-wise soil samples were collected. All the pedons were classified in the soil order of Ultisols and subclassified as Ustic Palehumult (evergreen forest), Ustic Haplohumult (moist deciduous forest) and Typic Haplustult (rubber plantation), respectively. The soil pH was found to be acidic in all the ecosystems ranging from 4.6 to 5.8. Chlorite, hydroxyl interlayered vermiculite (HIV), mica, kaolinite, feldspars, gibbsite and quartz dominated the mineral assemblages in the clay fractions of soils of natural forest systems. The losses of SiO2 in the non-clay fraction and corresponding enrichment of the component in the clay-sized fraction in all horizons indicated an active continuous weathering process in all the systems of this region. Clay accumulation by way of formation and translocation was highest in the lower horizons of the soils of evergreen (Bt2 at a depth range of 28–57 cm) and moist deciduous (Bt3C at a depth range of 23–150 cm) forest, whereas it was highest at Bt1 at a depth range of 15–28 cm in the plantation soil. The depth variations in the clay formations in natural and manmade forest systems provide insights into ecosystems regulated profile development under natural and man-made systems in the humid tropics, a vital information gap hitherto in soil pedogenesis of the humid tropics. Such pedogenic assessments along with the factors responsible for such modifications would provide important inputs in developing soil health management strategies in the humid tropics.

Conversion of Forest Hillslopes into Tea Fields Increases Soil Nutrient Losses through Surface Runoff

The conversion of forest hillslopes into tea fields changes the slope structure, soil properties, and vegetation, which may increase the great variations in the nitrogen (N) and phosphorus (P) losses through the surface runoff and induce agricultural non-point source pollution, particularly during the first years of conversion. Therefore, a natural forest system and a newly reclaimed tea system were compared to determine the land use conversion effects on the surface runoff and resulting N and P losses during 2013–2016. The results showed that the soil bulk density (BD) at all the depths and the saturated soil conductivities (Ks) in the surface soil were higher in the tea system than in the forest system, indicating that great land use conversion impacts soil’s physical and hydraulic properties. The annual surface runoff volumes and ratios were significantly higher in the tea system than in the forest system (p < 0.05), and this increased surface runoff was largely attributed to the slope structure and soil property changes. The total P (TP), dissolved P (DP), and particle P (PP) concentrations in the surface runoff volumes were similar in the two systems, while the total N (TN) concentrations were higher in the tea system than in the forest system due to the high N fertilizer application rates in the tea system. The percentages of dissolved N (DN) in the TN and particle N (PN) in the TN were, respectively, lower and higher in the tea system than in the forest system, which was associated with increased soil erodibility due to the land use conversion. The mean annual N and P losses through the surface runoff were higher in the tea system (11.07 ± 4.03 kg N ha−1 yr−1 and 1.73 ± 0.19 kg P ha−1 yr−1) than in the forest system (4.51 ± 0.66 kg N ha−1 yr−1 and 0.78 ± 0.18 kg P ha−1 yr−1). The N and P losses exponentially correlated with the surface runoff in both systems; however, the coefficients of determination (R2) were higher in the forest system than in the tea system, indicating that the exponential relationship between the surface runoff and the N and P losses should be more stable in the forest system than in the newly reclaimed tea system. Therefore, more effort should be dedicated to reducing the N and P losses though the surface runoff when forest hillslopes are converted into tea fields, particularly during the first three years of conversion.

Soil carbon dynamics in the temperate Himalayas: Impact of land use management

Food security and environmental health are directly linked with soil carbon (C). Soil C plays a crucial role in securing food and livelihood security for the Himalayan population besides maintaining the ecological balance in the Indian Himalayas. However, soil C is being severely depleted due to anthropogenic activities. It is well known that land use management strongly impacted the soil organic carbon (SOC) dynamics and also regulates the atmospheric C chemistry. Different types of cultivation practices, i.e., forest, plantations, and crops in the Kashmir Himalayas, India, has different abilities to conserve SOC and emit C in the form of carbon dioxide (CO2). Hence, five prominent land use systems (LUC) (e.g., natural forest, natural grassland, maize-field-converted from the forest, plantation, and paddy crop) of Kashmir Himalaya were evaluated to conserve SOC, reduce C emissions, improve soil properties and develop understanding SOC pools and its fractions variations under different land use management practices. The results revealed that at 0–20 cm and 20–40 cm profile, the soil under natural forest conserved the highest total organic carbon (TOC, 24.24 g kg−1 and 18.76 g kg−1), Walkley-black carbon (WBC, 18.23 g kg−1 and 14.10 g kg−1), very-labile-carbon (VLC, 8.65 g kg−1, and 6.30 g kg−1), labile-carbon (LC, 3.58 g kg−1 and 3.14 g kg−1), less-labile-carbon (VLC, 2.59 g kg−1, and 2.00 g kg−1), non-labile-carbon (NLC, 3.41 g kg−1 and 2.66 g kg-1), TOC stock (45.88 Mg ha−1 and 41.16 Mg ha−1), WBC stock (34.50 Mg ha−1 and 30.94 Mg ha−1), active carbon pools (AC, 23.14 Mg ha−1 and 20.66 Mg ha−1), passive carbon pools (PC, 11.40 Mg ha−1 and 10.26 Mg ha−1) and carbon management index (CMI, 100), followed by the natural grassland. However, the lowest C storage was reported in paddy cropland. The soils under natural forest and natural grassland systems had a greater amount of VLC, LC, LLC, and NLC fraction than other land uses at both depths. On the other hand, maize-field-converted-from-forest-land-use soils had a higher proportion of NLC fraction than paddy soils; nonetheless, the NLC pool was maximum in natural forest soil. LUS based on forest crops maintains more SOC, while agricultural crops, such as paddy and maize, tend to emit more C in the Himalayan region. Therefore, research findings suggest that SOC under the Kashmir Himalayas can be protected by adopting suitable LUS, namely forest soil protection, and by placing some areas under plantations. The areas under the rice and maize fields emit more CO2, hence, there is a need to adopt the conservation effective measure to conserve the SOC without compromising farm productivity.

Nghiên cứu vai trò chỉ thị sinh học của Collembola trong đánh giá chất lượng đất ở khu vực Chạm Chu, Tuyên Quang

Collembola communities are differently affected by land use practices. This study relies on the relationships between Collembola community structures and land use systems as a proxy for characterizing changes in soil quality. Thus, Collembola community structure (density, richness of Collembola morphotypes, eco-morphological groups - edaphic, hemiedaphic and epigeic) were examined in agro-forestry ecosystems to evaluate the discriminative power of the Collembola community structure. Fifteen morphotypes of Collembola were recorded in this study, 4 belonging to the edaphic eco-morphological group, 6 hemiedaphic, and 5 epigeic. The hemiedaphic and epigeic groups, in agricultural system, were more influenced by changes in land uses than the groups in natural forest system. Collembola eco-morphological groups and density were better predictors for ecosystem functioning and can be used to distinguish differences between soil uses, reducing laboratory analysis time.

Evaluation of the effects of conservation practices carried out in the 1970s on soil properties in the Eastern Region of Paraguay

AbstractSoils in subtropical and tropical regions are extremely fragile to perturbations due to their sandy texture, acid nature, low soil organic carbon (SOC) and low cation exchange capacity. In Paraguay, deforestation and subsequent cultivation affect 60% of the land. Certain conservation practices were carried out in the 1970s in response to the important degree of degradation caused by the soil degradative processes. Although the management of crop soils is still very intensive, to date there is no data on how the practices are affecting the sustainability of the system. The objective of this study was to evaluate the chemical and physical properties of three subtropical soils (Ultisol, Alfisol and Oxisol) under different agricultural systems and types of management, aimed at conservation, in the Eastern Region of Paraguay. The agricultural systems differ in the main crop (soybean or maize) and rotation crop (oat, turnip, crotalaria, lupins, maize). The soil properties were compared with those in disturbed natural forests and eucalypt plantations established on former agricultural land. The physical and chemical properties of the soil were determined in the 0 to 40 cm layer. The soils in the disturbed natural forest systems were less acidic and contained more Ca, Mg and K than the cultivated soils. Relative to the seminatural forests, the cultivated soils contained 20 to 40% less SOC and had lower macronutrient reserves and higher bulk density (up to 1.45 g cm−3). The SOC was higher in the agricultural systems with oats sown as a rotation crop in winter. By contrast, the N content was higher in systems with lupins or turnips grown in winter. Even when managed using conservation practices (direct sowing, retention of harvest residues, green manure), the soils in the agricultural systems under study displayed signs of physical and chemical degradation. The findings show that these conservation practices are not sufficient to correct the impact of intensive agricultural management.

Land-use systems regulate carbon geochemistry in the temperate Himalayas, India

The Himalayan ecosystem is critical for ecological security and environmental sustainability. However, continuous deforestation is posing a serious threat to Himalayan sustainability. Changing land-use systems exert a tenacious impact on soil carbon (C) dynamics and regulate C emissions from Himalayan ecosystem. Therefore, this study was conducted to determine the changes in different C pools and associated soil properties under diverse land-use systems, viz. natural forest, natural grassland, maize field converted from the forest, plantation, and paddy field of temperate Himalaya in the surface (0–20 cm) and subsurface (20–40 cm) soils. The highest total organic carbon (24.24 g kg−1) and Walkley-black carbon contents (18.23 g kg−1), total organic carbon (45.88 Mg ha−1), and Walkley-black carbon stocks (34.50 Mg ha−1) were recorded in natural forest in surface soil (0–20 cm depth), while soil under paddy field had least total organic carbon (36.45 Mg ha−1) and Walkley-black carbon stocks (27.40 Mg ha−1) in surface soil (0–20 cm depth). The conversion of natural forest into paddy land results in 47.36% C losses. Among the cultivated land-use system, minimum C losses (29.0%) from different pools over natural forest system were reported under maize-filed converted from forest system. Land conversion causes more C losses (21.0%) in surface soil (0–20 cm depth) as compared to subsurface soil. Furthermore, conversion of forest land into paddy fields increased soil pH by 5.9% and reduced total nitrogen contents and microbial population by 28.0% and 7.0%, respectively. However, the intensity of total nitrogen and microbial population reduction was the lowest under maize fields converted from the forest system. The study suggested that the conversion of natural forest to agricultural land must be discouraged in the temperate Himalayan region. However, to feed the growing population, converted forest land can be brought under conservation effective maize-based systems to reduce C loss from the intensive land use and contribute to soil quality improvements and climate change mitigation.

'Only One Earth' – Celebrating soil science on World Environment Day 2022

'Only One Earth' – Celebrating soil science on World Environment Day 2022

Spatial dependency of soil chemicals in production systems in the anthropogenic dark earth

In general, anthrosols refer to anthropic soils of high fertility, but the concentration of these nutrients may vary according to the occupation of indigenous people in the past or due to current soil use. This study aimed to evaluate the spatial variability of the chemical attributes of the soil in areas of guandu bean production and pasture and to compare with natural forest systems on anthropogenic dark earth (ADE). For this assessment, 88 sampling points were selected in the area with natural forest vegetation and pasture and 90 sampling points in an area of guandu bean production. Soil samples were collected from layers 0.00–0.05, 0.05–0.10, and 0.10–0.20 m. Chemical analyses of the soil were conducted to determine organic matter, pH, aluminium, soil acidity, phosphorus, potassium, calcium, magnesium, cation-exchange capacity, sum of bases, and base saturation (V%). Data were analyzed using descriptive statistics and geostatistics to sample range, and sample density was estimated for each attribute. Guandu bean showed high content of soil organic matter in relation to pasture in the superficial layer (0.00–0.05 m). Based on sample density, lower variability and higher spatial continuity were observed for guandu bean in relation to pasture and natural forest in the layers of 0.00–0.05 and 0.05–0.10 m. It was found that the use and continuous management of ADE areas alter the content and distribution of soil fertility and, in some cases, may even improve chemical attributes when compared with areas not used with agricultural crops.

Multivariate relationships between litter productivity and its drivers in a tropical karst seasonal rainforest

Litter is a vital component of ecosystem functionality, which is inherently linked to net primary productivity and global biogeochemical cycles. To better understand the drivers that modify net primary productivity, we need to disentangle the processes that underly changes in the generation of litter. We employed structural equation models (SEMs) to test for the direct and indirect effects of biodiversity, the stand structural attributes, and abiotic drivers on annual litter production in a tropical karst seasonal rainforest. For this study, annual litter production was evaluated over a five-year period in 90 permanent sample litter traps in a dynamic 15-ha long-term forest plot in Southern China. For each circular plot stand (with central litter traps) we quantified biodiversity, structural variations, basal area, and growth rate, which are important for net primary productivity. The four best-fit SEMs with different metrics of biodiversity for the paths between biodiversity, structural attributes, abiotic drivers, and annual litter production had a similar goodness of fit to the data. They accounted for 42.7–47.8% of the variation in annual litter production, 4.7–16.8% of the variation in stand-level growth rate, 29.3% of the variation in stand-level basal area, 8.2–13.2% of the variation in stand structural variation, and 4.4–6.5% of the variation in biodiversity. Although biodiversity had a positive effect on annual litter production through direct or indirect effects via the stand-level growth rate, abiotic drivers had the strongest impacts on annual litter production. We also found that the structural attributes of the stands had positive effects on the annual litter production; however, only the stand-level growth rate had significant consistently positive effects on annual litter production in the four best-fit SEMs. These results implied that annual litter production is most strongly driven by abiotic factors, followed by stand structural attributes and biodiversity. Theoretically, our study supports that niche differentiation and facilitation might enhance productivity; however, this enhanced capacity is primarily contingent on how abiotic variations are controlled in the sampling of natural karst forest systems. Biodiversity and the conservation of specific habitats should therefore be a key component in the management of forest resources, forest conservation, and sustainability.

Neighbour effects do not always show consistent patterns, contrast of seed trait matters: evidence from a seed-rodent mutualism study

Coexisting plant species often share the same animal mutualists and enemies. The selection preference of an animal on a focal individual is not only directly affected by the focal individual’s intrinsic traits, but also indirectly affected by conspecific or interspecific neighbouring individuals. Many studies often show inconsistent neighbour effects by comparison of the results between the presence and absence of neighbours, without considering the contrasting functional traits between the focal individual and the neighbours. Rodent-seed interaction that is ubiquitous in many ecosystems was selected to test the neighbour effect by using artificial seeds with different tannin contents, a vital seed trait that directly influences rodent foraging preference. I compared the seed predation and dispersal preference of rodents by monitoring the fate of 1920 artificial seeds with different absolute tannin contents (from 0 to 25%) among three categories of neighbouring seeds with tannin contents of 0%, 10% and 25%, respectively. Obvious neighbour effects were observed, although the magnitude and direction of the effects differed among different processes of scatter-hoarding behaviour. Furthermore, the neighbour effect did not show a consistent pattern among seeds with different tannin contents. Our results strongly suggested that the neighbour effects of coexisting species should be considered when evaluating the foraging preferences of animal mutualists/predators upon a specific plant species. The contrasting functional traits between focal plants and neighbouring individuals should be considered when studying neighbour effects. By using the artificial seed study system, I found that the contrast of tannin content could explain the inconsistent patterns of neighbour effects (i.e. the fate of a specific seed is influenced by its neighbouring seeds) among different seeds. In natural forest systems, plant seeds have a diverse array of traits, all of which markedly affect rodent foraging behaviour. Furthermore, a large spatio-temporal variation in seed production among species may result in a distinct variation in the relative densities of different seeds, which in turn may lead to even more complex neighbour effects at the whole forest community level. Our results strongly suggested that the neighbour effects of coexisting species of seeds should be considered when evaluating seed dispersal and predation of a specific species. The contrasting seed traits between focal plants and neighbouring individuals should be considered when studying neighbour effects.

Variation in soil properties under different cropping and other land-use systems in Dura catchment, Northern Ethiopia.

There are limited reports about the impacts of long-term cropping and land-use systems (CLUS) on soil properties and nutrient stocks under smallholder farmers' conditions in developing countries. The objective of this research was to examine variation in soil properties and OC and TN stocks across the different CLUS in Dura sub-catchment, northern Ethiopia. Surveys and discussions on field history were used to identify nine CLUS, namely, tef (Eragrostis tef (Zucc) Trot)) mono-cropping (TM), maize (Zea mays L.) mono-cropping (MM), cauliflower (Brassica oleracea var. botrytis)-maize intercropping (IC1), red beet (Beta Vulgaris)-maize intercropping (IC2), cauliflower-tef-maize rotation (R1), onion (Allium cepa L.)-maize-onion rotation (R2), tr eated gully (TG), untreated gully (UTG), and natural forest system (NF). A total of 27 composite soil samples were randomly collected from the CLUS for soil analysis. Data were subjected to one-way analysis of variance and PCA. The lowest and highest bulk density was determined from NF (1.19 Mg m-3) and UTG (1.77 Mg m-3), respectively. Soil pH, EC and CEC varied significantly among the CLUS. The highest CEC (50.3 cmolc kg-1) was reported under TG followed by NF. The highest soil OC stock (175.3 Mg C ha-1) and TN stock (13.6 Mg C ha-1) were found from NF. The PCA chosen soil properties explained 87% of the soil quality variability among the CLUS. Such soil properties and nutrient stocks variability among the CLUS suggested that introduction of suitable management practices that sustain the soil system of the CLUS with poor soil properties and nutrient stocks are crucial for the study area conditions.

Contrasting land use systems and soil organic matter quality and temperature sensitivity in North Eastern India

Although quality of soil organic matter (SOM) plays an important role in carbon (C) cycling of cropland and natural ecosystems under the changing climatic scenario, its impact on temperature sensitivity (Q10) is seldom studied together in surface and sub-surface soils of natural and managed ecosystems situated at different altitudes. So, a study was conducted by collecting soil samples from 0 to 15 and 15 to 30 cm depths under natural forest (NF), mulberry plantation (MP), rice-mustard (RM) and rice-fallow (RF) systems of north-eastern region of India to find out the quality and Q10 of SOM under varying land uses at different altitudes. Soils were incubated at 15, 25 and 35 °C for 52 days to estimate C decay rates (k), intermediate (after 24 day) Q10(24), final Q10, activation energy (Ea) and SOM quality parameters. Results revealed that cumulative CO2 emission was the lowest under NF at 15 °C, while it was the lowest under RF at 35 °C. The proportion of C-mineralized to total soil organic C (SOC) was the highest under RF (situated at higher altitude) and the lowest under NF system (situated at lower altitude). The SOC of the NF system had the highest Q10 value and higher recalcitrant C. The Q10 values of NF were ∼16 and 44% higher in the 0–15 and 15−30 cm soil layers, respectively than managed ecosystems. The ratios of microbial biomass C (MBC) to SOC and Ea were well correlated (P < 0.05) with Q10. The Q10(24) of surface soil was higher in managed ecosystems, but Q10 was higher for sub-surface C in the natural ecosystem. Hence, protecting natural ecosystems is very important to mitigate climate change. We found MBC/SOC and Ea to be better predictors of SOM quality and these should be included in soil C models for predicting C dynamics. Path analysis and PCA analysis revealed that soil variants, SOM quality and C pools significantly affected Q10 but climatic variables had nonsignificant impact on Q10.

Susceptibility of Eurasian Scots pine, Pinus sylvestris L., to the aggressive North American mountain pine beetle, Dendroctonus ponderosae Hopkins

Introductions of alien forest insects can exert substantial ecological and economic impacts on natural forest systems. The mountain pine beetle, Dendroctonus ponderosae Hopkins, an aggressive bark beetle native to western North America, kills mature pines at outbreak levels and is currently expanding its geographic, altitudinal and host ranges across the continent. Its oligophagous feeding behavior and its ability to kill novel hosts in newly invaded areas of Alberta, Canada suggest that this insect could threaten pine forests in other regions of the world. Little is known of the susceptibility of Scots pine, Pinus sylvestris L., to mountain pine beetle. Scots pine is a potential novel host common to forests across Eurasia and introduced to North America. Laboratory studies indicate the insects can colonize and reproduce in harvested logs of the host. We measured outcomes of an outbreak by mountain pine beetle in mixed stands of mature Scots pine and ponderosa pine, P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm., a historical host for the insect, in the Black Hills of South Dakota, U.S.A. We conducted a retrospective assessment of beetle attack and tree mortality of 165 trees (54 Scots pine and 111 ponderosa pine) of similar size and proximity that experienced high beetle pressure for three to four years ending in 2015. Our results show that mountain pine beetle can detect and attack live trees of Scots pine. Notably, we found that nearly 90% of Scots pines showed signs of attack, while no evidence of attack was found on the historical host in mixed stands. However, we found that Scots pines received half the attack density and demonstrated fifteen fold less likelihood of mortality in one year’s time relative to ponderosa pine in nearby stands. These results are important for assessing the potential for mountain pine beetle to kill trees in Eurasia and North America in Scots pine stands.

Strip Clear-Cutting Application and Logging Typologies for Renaturalization of Pine Afforestation—A Case Study

Renaturalization treatment in black pine afforestation is an important topic that should be considered. There is a need to favor the evolution of artificial pine forests toward natural forest systems. Overall, this study focused on pine forests, and suggests one typology of clear-cutting (dismantling cutting) on strips, which is associated with different extraction management techniques. Some ecological and environmental aspects associated with renaturalization treatments that have been applied by different mechanizations in black pine afforestation have been highlighted, as well as how renaturalization and the active ecological management of these stands could affect soil and vegetation. The main objectives of this research were to: (1) analyze the impact of silvicultural treatment and logging activities on forest soil, and (2) assess tree regeneration and floristic biodiversity in an ecological management system, in terms of both quantity and quality characteristics. These analyses were planned to obtain an overview of the environmental impact related to a multifunctional approach to the forest management of black pine afforestation. Essentially, the answers to the main research questions are: (1) less invasive extraction systems seem to use a cable yarder and forest winch; (2) a clear soil recovery trend with good capabilities is visible, in particular for the two extraction systems by cable; however, over a three-year period, only a partial but substantial recovery has been shown; (3) in general, silvicultural treatment showed qualitative and quantitative improvement in terms of tree regeneration; in particular, the extraction systems by forest winch and cable yarder showed better results; (4) silvicultural treatment seems not to have led to improvement at the level of the herbaceous and shrubby layers; however, clear differences are shown among the different harvesting systems. Significant recovery after use of the cable yarder was observed.

Participatory scenario development process in addressing potential impacts of anthropogenic activities on the ecosystem services of Mt. Marsabit forest, Kenya

The Marsabit Forest Reserve (MFR), a green island in an arid environmental setting, generates multiple ecosystem goods and services (ES) to the local community critical for their livelihoods. The forest has been experiencing substantial land conversion for town expansion, agriculture production and settlements threatening long-term ES provision. Sustaining the forest ES under increasing anthropogenic pressures is one of the great challenges of the Marsabit forest community. We used focus group discussions in the thirteen locations around the forest and individual key informant's interviews in the identification of drivers of change and their potential impacts on ES in MFR. We used the scenario development process (SDP) in coming up with four divergent but plausible exploratory scenarios. The study established that the main ES provided by the forest was, water, fuelwood, forage (dry season grazing resource), medicinal plants and timber for construction. Stakeholders identified population pressure, unsustainable utilisation of forest resources, institutional barriers to effective resource management, land use and climate change as the main drivers impacting ES provision in the forest. Land use change and climate change were considered the most significant drivers yet the most uncertain in the future impacting ES provision in the MFR. The SDP identified four alternative future scenarios for the MFR by the year 2044 with the Marsabit we want scenario identified as the most desirable future for the sustainable supply of ES with adequate adaptation to observed changes. Stakeholders came up with a joint action plan implementation matrix for the identified scenario while mitigating the negative aspects of the alternative scenarios. The results support the need for participatory land use planning that takes into to account the growing threat of climate change to natural forest systems.

Multifunctional natural forest silviculture economics revised: Challenges in meeting landowners’ and society's wants. A review

Aim of study: This paper objective focuses on the contribution of multifunctional natural forest silviculture, incorporating both private and public product managements, to forest and woodland economics.Area of study: Spain and California (USA).Material and methods: This conceptual article has developed a critical revision of the existing literature on the main economic issues for multifunctional natural forest silviculture in the last decades.Main results: Multifunctional natural silviculture has secular roots as a local practice, but as a science of the natural environment applied to the economic management of forest lands it is still in the process of maturation. Timber silviculture remains the central concern of forest economics investment in scientific publications. By contrast, silvicultural modeling of the natural growth of firewood, browse and other non-timber forest products from trees and shrubs receives scant attention in scientific journals. Even rarer are publications on multifunctional natural silviculture for forest and woodland managements, including environmental services geared to people’s active and passive consumption. Under this umbrella, private environmental self-consumption is represented by the amenities enjoyed by private non-industrial landowners. As for environmental public products, the most relevant are carbon, water, mushrooms, recreation, landscape and threatened biodiversity.Research highlights: This paper is a good example for the conceptual research on forestry techniques and economic concepts applied to multifunctional silviculture in Mediterranean areas of Spain and California. The combination of technical knowledge and private and public economic behaviors definitively contributes to the multifunctional management of natural forest systems.