A scoping review of human health co-benefits of forest-based climate change mitigation in Europe.

Climate change is a pressing global challenge with profound implications for human health. Forest-based climate change mitigation strategies, such as afforestation, reforestation, and sustainable forest management, offer promising solutions to mitigate climate change and simultaneously yield substantial co-benefits for human health. The objective of this scoping review was to examine research trends related to the interdisciplinary nexus between forests as carbon sinks and human health co-benefits. We developed a conceptual framework model, supporting the inclusion of exposure pathways, such as recreational opportunities or aesthetic experiences, in the co-benefit context. We used a scoping review methodology to identify the proportion of European research on forest-based mitigation strategies that acknowledge the interconnection between mitigation strategies and human impacts. We also aimed to assess whether synergies and trade-offs between forest-based carbon sink capacity and human co-benefits has been analysed and quantified. From the initial 4,062 records retrieved, 349 reports analysed European forest management principles and factors related to climate change mitigation capacity. Of those, 97 studies acknowledged human co-benefits and 13 studies quantified the impacts on exposure pathways or health co-benefits and were included for full review. Our analysis demonstrates that there is potential for synergies related to optimising carbon sink capacity together with human co-benefits, but there is currently a lack of holistic research approaches assessing these interrelationships. We suggest enhanced interdisciplinary efforts, using for example multideterminant modelling approaches, to advance evidence and understanding of the forest and health nexus in the context of climate change mitigation.

Natural disturbance regimes as a guide for sustainable forest management in Europe.

In Europe, forest management has controlled forest dynamics to sustain commodity production over multiple centuries. Yet over-regulation for growth and yield diminishes resilience to environmental stress as well as threatens biodiversity, leading to increasing forest susceptibility to an array of disturbances. These trends have stimulated interest in alternative management systems, including natural dynamics silviculture (NDS). NDS aims to emulate natural disturbance dynamics at stand and landscape scales through silvicultural manipulations of forest structure and landscape patterns. We adapted a "Comparability Index" (CI) to assess convergence/divergence between natural disturbances and forest management effects. We extended the original CI concept based on disturbance size and frequency by adding the residual structure of canopy trees after a disturbance as a third dimension. We populated the model by compiling data on natural disturbance dynamics and management from 13 countries in Europe, covering four major forest types (i.e., spruce, beech, oak, and pine-dominated forests). We found that natural disturbances are highly variable in size, frequency, and residual structure, but European forest management fails to encompass this complexity. Silviculture in Europe is skewed toward even-aged systems, used predominately (72.9% of management) across the countries assessed. The residual structure proved crucial in the comparison of natural disturbances and silvicultural systems. CI indicated the highest congruence between uneven-aged silvicultural systems and key natural disturbance attributes. Even so, uneven-aged practices emulated only a portion of the complexity associated with natural disturbance effects. The remaining silvicultural systems perform poorly in terms of retention compared to tree survivorship after natural disturbances. We suggest that NDS can enrich Europe's portfolio of management systems, for example where wood production is not the primary objective. NDS is especially relevant to forests managed for habitat quality, risk reduction, and a variety of ecosystem services. We suggest a holistic approach integrating NDS with more conventional practices.

Identification and genetic diversity analysis of a male-sterile gene (MS1) in Japanese cedar (Cryptomeria japonica D. Don).

Identifying causative genes for a target trait in conifer reproduction is challenging for species lacking whole-genome sequences. In this study, we searched for the male-sterility gene (MS1) in Cryptomeria japonica, aiming to promote marker-assisted selection (MAS) of male-sterile C. japonica to reduce the pollinosis caused by pollen dispersal from artificial C. japonica forests in Japan. We searched for mRNA sequences expressed in male strobili and found the gene CJt020762, coding for a lipid transfer protein containing a 4-bp deletion specific to male-sterile individuals. We also found a 30-bp deletion by sequencing the entire gene of another individual with the ms1. All nine breeding materials with the allele ms1 had either a 4-bp or 30-bp deletion in gene CJt020762, both of which are expected to result in faulty gene transcription and function. Furthermore, the 30-bp deletion was detected from three of five individuals in the Ishinomaki natural forest. From our findings, CJt020762 was considered to be the causative gene of MS1. Thus, by performing MAS using two deletion mutations as a DNA marker, it will be possible to find novel breeding materials of C. japonica with the allele ms1 adapted to the unique environment of each region of the Japanese archipelago.

Short-term impacts of forest clear-cut on soil structure and consequences for organic matter composition and nutrient speciation: A case study.

Clear-cuts of forests severely affect soil structure and thus soil organic matter (SOM) and nutrient cycling dynamics therein, though with yet unknown consequences for SOM composition as well as phosphorus (P) and sulfur (S) chemical form within the soil microaggregate size fraction. To determine the effects of conventional clear-cutting on soil chemistry in a Cambisol of the Wüstebach Forest (northwestern Germany), we sampled the mineral A- and B-horizons prior to clear-cut as well as 10 and 24 month thereafter. We measured the SOM composition of soil microaggregates using pyrolysis field ionization mass spectrometry (Py-FIMS), as well as P and S chemical form and speciation using wet-chemical extractions and X-ray absorption near edge structure (XANES) spectroscopy. We found that clear-cut led to an increase of the microaggregate size fraction up to 6% due to break-down of macroaggregates and initially significantly increased total elemental concentrations (C, N, P, S) due to the introduction of slash-residues. The SOM of slash-residues consisted to a substantial amount of sterols and was generally found to be of low thermal stability and probably did not contribute to aggregate stability. Deterioration of the aggregate structure probably led to an exposure of originally inaccessible sites within aggregates to the attack by soil microorganisms and thus to an increased P and S turnover as reflected in a significantly reduction of available P proportions (4 to 7%) and a reduction of the most reduced S forms (5%). A probable increased microbial activity and contribution to SOM after clear-cut is also reflected in the significantly increasing hexose:pentose ratio by 0.25 between 10 and 24 month after clear-cut, significantly increasing the general thermal stability of SOM in the microaggregate size fraction and believed to contribute to aggregate stability. This indicated that a first deterioration of the aggregate structure after clear-cut might in the long-term be remediated with time.

The reduction effects of riparian reforestation on runoff and nutrient export based on AnnAGNPS model in a small typical watershed, China.

The continuous deterioration of the aquatic environment in rivers and streams is increasingly causing social and political tensions. To alleviate aquatic environmental problems, especially for the nonpoint source pollution, establishment of riparian forest buffers has been demonstrated as an effective control measure. However, few comprehensive studies of the reduction effects of riparian reforestation on the aquatic environment have been performed, particularly in identifying the suitable widths of reforestation projects. In this paper, the Annualized Agricultural Non-Point Source (AnnAGNPS) model was used to simulate the reduction effects of riparian reforestation on runoff and nutrient loads in Wucun watershed, China. The results showed that 20-m, 40-m, and 60-m widths of riparian buffer reforestation had significant effects on the yearly loads of total nitrogen (TN) and total phosphorus (TP), with reduced rates of 23.21 to 56.2% and 18.16 to 52.14%, respectively. The reduction effect on annual runoff varied from 2.8 to 5.4%. Furthermore, the reduction effect of nutrients performed best during the transition period, while the best runoff reduction was found during the dry period. These distinct reductions indicated that the implementation of riparian forest buffers was capable of reducing the risk and frequency of flooding and eutrophication, especially during the wet and transition periods. Additionally, the 20-m width of riparian buffer reforestation achieved the highest reduction efficiency for runoff, and the 40-m width was the most suitable reforested riparian buffer width for TN and TP. Therefore, 40 m may be the optimum buffer width for the implementation of riparian reforestation in the Wucun watershed. These research results provided scientific information on selecting the optimum buffer width for aquatic environmental regulators and managers as the reduction effects of different widths of riparian buffers on runoff and nutrients were different when considering buffer reforestation.

Assessing effectiveness of long-term forestry best management practices on stream water quality at a basin scale-a case study in Southern USA.

Forestry best management practices (BMPs) have proven to be very effective in protecting adjacent stream water quality at the plot scale. However, our knowledge is incomplete about the effectiveness of forestry BMPs in large watersheds where industrial forests are intensively managed. In this study, we compared long-term concentrations and loadings of total suspended solids (TSS), nitrate/nitrite nitrogen (NO3NO2-N), total Kjeldahl nitrogen (TKN), and total phosphorus (TP) before (1978-1988) and after extensive implementation of forestry BMPs (1994-2008) at the outlet of a 5000-km2 river basin that is predominately covered by intensively managed pine forests in Central Louisiana, USA. Our study shows that after extensive BMP implementation, both concentrations and loads of TSS in the basin outlet decreased significantly from 34 to 25 mg L-1 and from 55,000 to 36,700 t year-1, respectively. However, no significant difference was found in NO3NO2-N, TKN, and TP concentrations between the two periods. The results of nutrient loadings varied, whereby the annual nitrogen loading declined without significant differences (from 1790 to 1600 t year-1 for TKN and from 176 to 158 t year-1 for NO3NO2-N, respectively) but the annual TP loading increased significantly (from 152 to 192 t year-1) after BMP implementation. The increase in TP loading is likely due to an increased application of phosphorus fertilizer, which offset BMPs' effects especially during high-flow conditions. These results strongly suggest that current forestry BMPs in this region are effective in reducing sediment loading, but current BMP guidelines for fertilization and nutrient management need to be reviewed and improved.

More fishers and fewer martens due to cumulative effects of forest management and climate change as evidenced from local knowledge.

BACKGROUND: Monitoring of fur-bearing species populations is relatively rare due to their low densities. In addition to catch data, trappers' experience provides information on the ecology and status of the harvested species. Fisher (Pekania pennanti) and American marten (Martes americana) are mustelids that are sensitive to forest management and therefore considered to be ecological indicators of forest health. Fisher populations have increased in eastern North America since the early 2000s and this could have resulted in a northeastern extension of the species' range and increased overlap with marten's range. Moreover, habitats of both species are subject to natural and anthropogenic disturbances. The objective of this study was to document the knowledge held by local trappers in the northern area of sympatry between fisher and marten to identify factors that could explain variation in populations of the two species and interactions between them. METHOD: Forty-one semi-directed interviews with Indigenous and non-Indigenous trappers in the Abitibi-Témiscamingue region of western Quebec (Canada), at the northern limit of the overlapping ranges of the two mustelid species. RESULTS: Trappers highlighted the lack of exclusivity of marten and fisher to coniferous forests, although marten is more closely associated with them than is fisher. Fisher apparently also takes advantage of open environments, including agroforestry systems. Moreover, climate change increases the frequency of freeze-thaw events that cause the formation of an ice crust on the snow surface, which favors fisher movements. CONCLUSION: The fisher was identified as a competitor and even a predator of the marten. Furthermore, the fisher is less affected than the marten by forest management, and it also seems to benefit from climate change to a greater extent.

Nutrient limitation in tropical secondary forests following different management practices.

Secondary forests now make up more than one-half of all tropical forests, and constraints on their biomass accumulation will influence the strength of the terrestrial carbon (C) sink in the coming decades. However the variance in secondary tropical forest biomass for a given stand age and climate is high and our understanding of why is limited. We constructed a model of terrestrial C, nitrogen (N), and phosphorus (P) cycling to examine the influence of disturbance and management practices on nutrient limitation and biomass recovery in secondary tropical forests. The model predicted that N limited the rate of forest recovery in the first few decades following harvest, but that this limitation switched to P approximately 30-40 yr after abandonment, consistent with field data on N and P cycling from secondary tropical forest chronosequences. Simulated biomass recovery agreed well with field data of biomass accumulation following harvest (R2  = 0.80). Model results showed that if all biomass remained on site following a severe disturbance such as blowdown, regrowth approached pre-disturbance biomass in 80-90 yr, and recovery was faster following smaller disturbances such as selective logging. Field data from regrowth on abandoned pastures were consistent with simulated losses of nutrients in soil organic matter, particularly P. Following any forest disturbance that involved the removal of nutrients (i.e., except blowdown), forest regrowth produced reduced biomass relative to the initial state as a result of nutrient loss through harvest, leaching and/or sequestration by secondary minerals. Differences in nutrient availability accounted for 49-94% of the variance in secondary forest biomass C at a given stand age. Management lessons from this study are the importance of strategies that help retain nutrients on site, recognizing the role of coarse woody debris in immobilization and subsequent release of nutrients, and the potential for nutrient additions to enhance biomass growth and recovery in secondary tropical forests.

Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests.

Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m(-2)·yr(-1)), P addition (15 g P m(-2)·yr(-1)), and N and P addition (15 + 15 g N and P m(-2)·yr(-1), respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

Ethnopedology and soil quality of bamboo (Bambusa sp.) based agroforestry system.

It is widely recognized that farmers' hold important knowledge of folk soil classification for agricultural land for its uses, yet little has been studied for traditional agroforestry systems. This article explores the ethnopedology of bamboo (Bambusa sp.) based agroforestry system in North East India, and establishes the relationship of soil quality index (SQI) with bamboo productivity. The study revealed four basic folk soil (mati) types: kalo (black soil), lal (red soil), pathal (stony soil) and balu (sandy soil). Of these, lal mati soil was the most predominant soil type (~ 40%) in bamboo-based agroforestry system. Soil physio-chemical parameters were studied to validate the farmers' soil hierarchal classification and also to correlate with productivity of the bamboo stand. Farmers' hierarchal folk soil classification was consistent with the laboratory scientific analysis. Culm production (i.e. measure of productivity of bamboo) was the highest (27culmsclump(-1)) in kalo mati (black soil) and the lowest (19culmsclump(-1)) in balu mati (sandy soil). Linear correlation of individual soil quality parameter with bamboo productivity explained 16 to 49% of the variability. A multiple correlation of the best fitted linear soil quality parameter (soil organic carbon or SOC, water holding capacity or WHC, total nitrogen) with productivity improved explanatory power to 53%. Development of SQI from ten relevant soil quality parameters and its correlation with bamboo productivity explained the 64% of the variation and therefore, suggest SQI as the best determinant of bamboo yield. Data presented indicate that the kalo mati (black soil) is sustainable or sustainable with high input. However, the other three folk soil types (red, stony and sandy soil) are also sustainable but for other land uses. Therefore, ethnopedological studies may move beyond routine laboratory analysis and incorporate SQI for assessing the sustainability of land uses managed by the farmers'. Additional research is required to incorporate principal component analysis for improving the SQI and site potential assessment. It is also important to evaluate the minimum data set (MDS) required for SQI and productivity assessment in agroforestry systems.

Hybrid MCDA Methods to Integrate Multiple Ecosystem Services in Forest Management Planning: A Critical Review.

Multi-criteria decision analysis (MCDA) is a decision aid frequently used in the field of forest management planning. It includes the evaluation of multiple criteria such as the production of timber and non-timber forest products and tangible as well as intangible values of ecosystem services (ES). Hence, it is beneficial compared to those methods that take a purely financial perspective. Accordingly, MCDA methods are increasingly popular in the wide field of sustainability assessment. Hybrid approaches allow aggregating MCDA and, potentially, other decision-making techniques to make use of their individual benefits and leading to a more holistic view of the actual consequences that come with certain decisions. This review is providing a comprehensive overview of hybrid approaches that are used in forest management planning. Today, the scientific world is facing increasing challenges regarding the evaluation of ES and the trade-offs between them, for example between provisioning and regulating services. As the preferences of multiple stakeholders are essential to improve the decision process in multi-purpose forestry, participatory and hybrid approaches turn out to be of particular importance. Accordingly, hybrid methods show great potential for becoming most relevant in future decision making. Based on the review presented here, the development of models for the use in planning processes should focus on participatory modeling and the consideration of uncertainty regarding available information.

Biochar application during reforestation alters species present and soil chemistry.

Reforestation of landscapes is being used as a method for tackling climate change through carbon sequestration and land restoration, as well as increasing biodiversity and improving the provision of ecosystem services. The success of reforestation activities can be reduced by adverse field conditions, including those that reduce germination and survival of plants. One method for improving success is biochar addition to soil, which is not only known to improve soil carbon sequestration, but is also known to improve growth, health, germination and survival of plants. In this study, biochar was applied to soil at rates of 0, 1, 3 and 6 t ha(-1) along with a direct-seed forest species mix at three sites in western Victoria, Australia. Changes in soil chemistry, including total carbon, and germination and survival of species were measured over an 18 month period. Biochar was found to significantly increase total carbon by up to 15.6% on soils low in carbon, as well as alter electrical conductivity, Colwell phosphorous and nitrate- and ammonium-nitrogen. Biochar also increased the number of species present, and stem counts of Eucalyptus species whilst decreasing stem counts of Acacia species. Biochar has the potential to positively benefit reforestation activities, but site specific and plant-soil-biochar responses require targeted research.

Impacts of selective logging on inbreeding and gene flow in two Amazonian timber species with contrasting ecological and reproductive characteristics.

Selective logging in Brazil allows for the removal of up to 90% of trees above 50 cm diameter of a given timber species, independent of a species' life history characteristics or how quickly it will recover. The genetic and demographic effects of selective logging on two Amazonian timber species (Dipteryx odorata Leguminosae, Jacaranda copaia Bignoniaceae) with contrasting ecological and reproductive characteristics were assessed in the same forest. Genetic diversity and gene flow were characterized by genotyping adults and seed sampled before and after logging, using hypervariable microsatellite markers. Overall, there were no short-term genetic impacts on the J. copaia population, with commercial application of current Brazilian forest management regulations. In contrast, for D. Odorata, selective logging showed a range of genetic impacts, with a 10% loss of alleles, and reductions in siring by pollen from trees within the 546-ha study area (23-11%) and in the number of pollen donors per progeny array (2.8-1.6), illustrating the importance of the surrounding landscape. Asynchrony in flowering between D. odorata trees led to trees with no breeding partners, which could limit the species reproduction and regeneration under current regulations. The results are summarized with other published studies from the same site and the implications for forest management discussed. The different types and levels of impacts associated with each species support the idea that ecological and genetic information by species, ecological guild or reproductive group is essential in helping to derive sustainable logging guidelines for tropical forests.

The short-term effects of management changes on watertable position and nutrients in shallow groundwater in a harvested peatland forest.

Management changes such as drainage, fertilisation, afforestation and harvesting (clearfelling) of forested peatlands influence watertable (WT) position and groundwater concentrations of nutrients. This study investigated the impact of clearfelling of a peatland forest on WT and nutrient concentrations. Three areas were examined: (1) a regenerated riparian peatland buffer (RB) clearfelled four years prior to the present study (2) a recently clearfelled coniferous forest (CF) and (3) a standing, mature coniferous forest (SF), on which no harvesting took place. The WT remained consistently below 0.3 m during the pre-clearfelling period. Results showed there was an almost immediate rise in the WT after clearfelling and a rise to 0.15 m below ground level (bgl) within 10 months of clearfelling. Clearfelling of the forest increased dissolved reactive phosphorus concentrations (from an average of 28-230 µg L(-1)) in the shallow groundwater, likely caused by leaching from degrading brash mats.

Effects of calcite and magnesite application to a declining Masson pine forest on strongly acidified soil in Southwestern China.

Liming of strongly acidified soil under a Masson pine (Pinus massoniana Lamb.) forest was studied through a seven-year field manipulation experiment at Tieshanping, Chongqing in Southwestern China. To distinguish between the individual effects of Ca(2+) and Mg(2+) addition, we separately applied calcite (CaCO3) and magnesite (MgCO3), rather than using dolomite [CaMg(CO3)2]. Both calcite and magnesite additions caused a significant increase in pH and a decrease in dissolved inorganic monomeric aluminium (Ali) concentration of soil water. Ecological recovery included increases of herb biomass (both treatments) and Mg content in Masson pine needles (magnesite treatment only). However, the growth rate of Masson pine did not increase under either treatment, possibly because of nutrient imbalance due to phosphorus (P) deficiency or limited observation period. In China, acid deposition in forest ecosystems commonly coincides with large inputs of atmogenic Ca(2+), both enhancing Mg(2+) leaching. Calcite addition may further decrease the Mg(2+) availability in soil water, thereby exacerbating Mg(2+) deficiency in the acidified forest soils of southern and southwestern China. The effect of anthropogenic acidification of naturally acid forest soils on P availability needs further study.

[Effects of stand density on Oligostachyum lubricum leaf carbon, nitrogen, and phosphorus stoichiometry and nutrient resorption].

Taking pure Oligostachyum lubricum forest as test object, this paper studied the matured and withered leaves carbon (C), nitrogen (N), and phosphorus (P) stoichiometry and N and P resorption patterns of 1-3 years old stands at the densities of 24600-29800 stem hm-2 (D, ), 37500-42600 stem hm-2 (D2 ), 46500 - 52800 stem hm-2 (D3), and 76500 - 85500 stem hm-2 (D4). With increasing stand density, the matured leaves C, N, and P contents and withered leaves C and P contents had an overall decrease, the withered leaves N content decreased after an initial increase, and the matured leaves C content at density )4 decreased dramatically. The leaf C/N and C/P ratio increased with increasing stand density, whereas the leaf N/P ratio increased first but decreased then. At stand densities D3 and D4, the leaf N and P utilization efficiencies were significantly higher than those at D, and D2. With increasing stand density, the leaf N resorption capacity increased after an initial decrease, while the leaf P resorption capacity increased steadily. At stand densities D,-D3, the matured leaves N/P ratio was 16.24-19.37, suggesting that the P limitation occurred, leaf establishment increased, and population increase and expansion enhanced. At density D4, the matured leaves N/P ratio was 13.42-15.74, implying that the N limitation strengthened, leaf withering and defoliation increased, and population increase inhibited. All the results indicated that O. lubricum could regulate its leaf C, N and P contents and stoichiometry and enhance the leaf N and P utilization efficiency and resorption capacity to adapt to the severe competition of environment resources at high stand density. In our experimental condition, 46500-52800 stem hm-2 could be the appropriate stand density for O. lubricum management.

Effects of increased nitrogen deposition and rotation length on long-term productivity of Cunninghamia lanceolata plantation in southern China.

Cunninghamia lanceolata (Lamb.) Hook. has been widely planted in subtropical China to meet increasing timber demands, leading to short-rotation practices that deplete soil nutrients. However, increased nitrogen (N) deposition offsets soil N depletion. While long-term experimental data investigating the coupled effects related to short rotation practices and increasing N deposition are scarce, applying model simulations may yield insights. In this study, the CenW3.1 model was validated and parameterized using data from pure C. lanceolata plantations. The model was then used to simulate various changes in long-term productivity. Results indicated that responses of productivity of C. lanceolata plantation to increased N deposition were more related to stand age than N addition, depending on the proportion and age of growing forests. Our results have also shown a rapid peak in growth and N dynamics. The peak is reached sooner and is higher under higher level of N deposition. Short rotation lengths had a greater effect on productivity and N dynamics than high N deposition levels. Productivity and N dynamics decreased as the rotation length decreased. Total productivity levels suggest that a 30-year rotation length maximizes productivity at the 4.9 kg N ha(-1) year(-1) deposition level. For a specific rotation length, higher N deposition levels resulted in greater overall ecosystem C and N storage, but this positive correlation tendency gradually slowed down with increasing N deposition levels. More pronounced differences in N deposition levels occurred as rotation length decreased. To sustain C. lanceolata plantation productivity without offsite detrimental N effects, the appropriate rotation length is about 20-30 years for N deposition levels below 50 kg N ha(-1) year(-1) and about 15-20 years for N deposition levels above 50 kg N ha(-1) year(-1). These results highlight the importance of assessing N effects on carbon management and the long-term productivity of forest ecosystems.