To predict the value of trade between countries, a differential gravity model of bilateral trade flows was formulated and estimated with panel data from 2005 to 2014 for each of the commodity groups HS44 (wood and articles of wood), HS47 (pulp of wood, fibrous cellulosic material) and HS48 (paper and paperboard). The parameters were estimated with a large database by ordinary least squares, fixed-effects and random-effects methods. For the three commodity groups, the results were stable across methods. For HS44, exports were inelastic (0.33 ± 0.19) with respect to the gross domestic product (GDP) of exporters and elastic (1.95 ± 0.15) with the GDP of importers. For HS47, exports were elastic with respect to the exporters GDP (1.67 ± 0.55) and importers GDP (1.10 ± 0.36). Exports of HS48 were inelastic with the exporters GDP (0.81 ± 0.21) and elastic with respect to the importers (1.00 ± 0.14). For all three products, there were marked decreases in exports in 2009 and 2012 independent of GDP. The estimated elasticities were used to predict the growth rate of trade flows from 2015 to 2020 based on exogenous GDP projections of the International Monetary Fund. Another application investigated the effects of the Trans-Pacific Partnership agreement on the trade of forest products between the 12 member countries.

Sustainable methods are required to protect newly planted tree seedlings from insect herbivore attack. To this end, here Norway spruce (Picea abies (L.) Karst.) seeds were treated with 2.5 mM nicotinamide (NIC), 2.5 mM nicotinic acid (NIA), 3 mM jasmonic acid (JA) or 0.2 mM 5-azacytidine (5-Aza), and 6-month-old seedlings grown from these seeds were planted at a reforestation area in central Sweden. Attack by pine weevils (Hylobius abietis) was reduced by 50 per cent by NIC treatment, 62.5 per cent by JA treatment and 25 per cent by 5-Aza treatment, when compared with seedlings grown from untreated seeds. Watering 18-month-old spruce seedlings with 2 mM NIC or 2 mM NIA did reduce attack during the first season in the field by 40 and 53 per cent, respectively, compared with untreated plants. Girdling was also reduced by the different treatments. Analysis of conifer seedlings treated with 5-Aza points at a possible involvement of epigenetic mechanisms in this defensive capacity. This is supported by a reduced level of DNA methylation in the needles of young spruce seedlings grown in a greenhouse from NIC-treated seeds. Seed treatment for seedling defense potentiation is simple, inexpensive and also a new approach for forestry with many potential applications.

This study analyzed differences between actual and modelled fire predictions for two recent fires that affected the Golestan National Park in northeastern Iran. FARSITE and FlamMap minimum travel time (MTT) fire modelling systems were used to compare spatial differences in burned area between observed and modelled fires. Then, the spatial variability in fire spread and behaviour related to differences in fuel types and topography was analyzed. Comparison between the observed and simulated fire perimeters showed a relatively good agreement. For both case studies, the simulations performed with the MTT algorithm presented slightly higher accuracy than the FARSITE ones. Although we found spatial differences in fire intensity and rate of spread modelling outputs, the average values in burned areas provided by FARSITE and FlamMap MTT simulations were very similar. The comparison of fire spread models provided a better understanding of their potential limits and differences in fire growth and behaviour predictions over heterogeneous-fuel landscapes, complex topography and changing weather conditions.

National forest inventories (NFIs) have to be properly designed in order to yield statistically representative data and make best use of limited resources. A key element to accomplish this is the knowledge of the local variability in the sampled forest stand features. In this study, we estimated the variability of tree taxonomic richness and carbon (C) stock in logged-over and unlogged lowland tropical forests of Papua New Guinea, to define the optimal plot and sample size needed to estimate these characteristics in the context of the forthcoming implementation of the new NFI. We used data from 133 one-hectare permanent sample plots to calculate the coefficient of variation (CV) of C stock and taxonomic richness at different simulated plot sizes. CV was seen to rapidly decrease with increasing plot size up to 0.2–0.3 ha for both features following an inverse-exponential trend. Optimum plot size ranged between 0.08 and 0.32 ha, with 75–164 plots needed to achieve an estimation within 5 per cent of the true mean (95 per cent confidence), depending on the stand feature and the previous silvicultural treatment. We concluded that the establishment of a network of 319 permanent sample plots between 0.2 and 0.3 ha in size would represent an efficient sampling scheme in lowland forests for the new NFI.

We studied the effects of Acacia seyal Del. intercropping and biochar soil amendment on soil physico-chemical properties and sorghum (Sorghum bicolor L.) yields in a two-year field experiment conducted on a silt loam site near Renk in South Sudan. A split-plot design with three replications was used. The main factor was tree-cropping system (dense acacia + sorghum, scattered acacia + sorghum, and sole sorghum) and biochar (0 and 10 Mg ha−1) was the subplot factor. The two acacia systems had lower soil pH, N and higher C/N ratios compared to the sole sorghum system. Biochar significantly increased soil C, exchangeable K+ contents, field capacity and available water content, but reduced soil exchangeable Ca2+ and effective CEC, and had no effect on soil pH. Acacia intercropping significantly reduced sorghum grain yields while biochar had no significant effect on sorghum yields. The land equivalent ratio (LER) for sorghum yield was 0.3 for both acacia systems in 2011, with or without biochar, but increased in 2012 to 0.6 for the scattered acacia system when combined with biochar. The reduction in sorghum yields by the A. seyal trees was probably due to a combination of competition for water and nutrients and shading. The lack of a yield response to biochar maybe due to insufficient time or too low a dosage. Further research is needed to test for the effects of tree intercropping and biochar and their interactions on soil properties and crop yields in drylands.

Concerns about sustainable management and conservation of multipurpose trees in their habitat have led to increased number of studies on the ecological characterization of their population. Such knowledge on Faidherbia albida, the most used tree in agroforestry parklands in Ethiopia, is limited. F. albida population was characterized in and compared between two agroforests having different conservation status in Northern Ethiopia. Population structural parameters along with environmental factors and human activities were assessed in 42 randomly installed plots using a transect method. Size class distribution was used to describe and analyze the species long-term population dynamics. Adult density was almost three times higher in Zongi agroforest (19.9 ± 2.9 trees ha−1) where the species has been conserved and managed for longer time compared to Abraha-atsbeha agroforest (7.9 ± 2.5 trees ha−1). The same trend was observed for tree morphological parameters which were significantly higher at Zongi than Abraha-atsbeha. However, size class distributions coefficient of skewness and the median diameter indicated a declining and vulnerable population at Zongi and an increasing population at Abraha-atsbeha. Species population characteristics were influenced by environmental factors such as altitude, stone cover, erosion severity, slope, and human-related disturbances including land use, fodder harvesting, distance away from the center of the village and proximity of household to the plots. The study confirms the impact of conservation, environmental factors and human disturbances on shaping F. albida population and recommends the consideration of the trade-offs between them to design effective conservation and management strategies to sustain F. albida agroforests.

The use of silvopasture systems on farms in the Northeastern United States has never been documented. Our objective was to gather baseline data to describe silvopasture practices and perspectives in the Northeastern United States. To accomplish this, we investigated the structure, management of, and reasons for use of silvopastures in New York state and New England through a series of interviews and inventories on 20 farms purposefully chosen as practicing silvopasture. Thematic content analysis was conducted to summarize interview results and identify trends related to silvopasture practices. Three farmers in this study had been practicing silvopasture on their farms over 30 years; the rest were new to silvopasture in the past 10 years. Only three of 20 farmers interviewed in this study had experience practicing silvopasture prior to implementing it on their farms. Forest conversion to silvopasture was the primary starting point for silvopastures observed on regional farms. Orchard, open field edge, outdoor living barn, and plantation silvopastures were also documented on multiple farms. Shade and a desire to maximize use of farm woodlands were primary reasons for silvopasture utilization. This research provides evidence that silvopastures are being used to diversify regional farms. For the practice to be advanced in the region further research is needed on the topic.

Population abundance estimates are important for management, but can be challenging in low density, wide-ranging, and endangered species, such as Sonoran pronghorn (Antilocapra americana sonoriensis). The Sonoran pronghorn population has been increasing; however, population estimates are currently derived from a biennial aerial count which does not provide survival or recruitment estimates. We identified individuals using noninvasively collected fecal DNA and used robust design capture-recapture to estimate abundance and survival for Sonoran pronghorn in the United States between 2013 and 2014. Separate population estimates were generated for developed water holes (drinkers) and drinker and non-drinker locations in 2014. The population using drinkers was 116 (95% CI: 102–131) and 121 individuals (95% CI: 112–132) in 2013 and 2014. The population estimate for all locations was 144 individuals (95% CI: 132–157). Adults had higher annual survival probabilities (0.83, 95% CI: 0.69-0.92) than fawns (0.41, 95% CI: 0.21–0.65). This new method of using targeted sampling and noninvasive genetic sampling capture-recapture with Sonoran pronghorn fecal DNA proved successful. Our results provided the first survival estimates for this population in over 2 decades as well as precise estimates of the population using drinkers. This method also presents opportunities for targeted sampling in other systems for broadly distributed species, such as in African savanna ecosystems, where many species congregate at watering sites.

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Payments to compensate landowners for carrying out costly land use measures which benefit endangered species and habitats have become an important policy instrument. When designing such payments, it is important to take into account that spatially connected habitats are more valuable for many species than isolated ones. One way of incentivizing landowners to provide connected habitats is by offering an agglomeration bonus, where landowners receive a payment if they conserve their land, and a bonus on top, if this land is spatially connected. Recent research compared the cost-effectiveness of the agglomeration bonus with two alternatives: an "all-or-nothing" agglomeration payment where landowners receive a payment only if the conserved land parcels have a certain level of spatial connectivity, and a spatially homogeneous payment where landowners receive a payment for conserved land parcels irrespective of their location. Depending on the parameters, the cost-effectiveness of the agglomeration bonus was found to be either dominated by one of the two other options or very close to the better performing option. This suggests that the agglomeration bonus should not be given priority as a policy design option. However, that finding is based on research that only considers single species. In the present research note we ask whether the same applies to two species when for one species the homogeneous payment and for the other the agglomeration payment is the most cost-effective payment design. When the aim is to conserve both species, we find that the agglomeration bonus is more cost-effective than the other two options, thus rehabilitating the bonus as a policy design option. The practical relevance of this insight is demonstrated in a case study.

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The rise of the Internet as a trade platform has resulted in a shift in the illegal wildlife trade. As a result of increased scrutiny that illegal wildlife trade is receiving, there are concerns that the online trade will move onto the darkweb. In this preliminary study, we provide a baseline of illegal wildlife trade on the darkweb. We downloaded and archived 9,852 items from the darkweb, then searched these based on a list of 121 keywords associated with illegal online wildlife trade, including 30 keywords associated with illegally traded elephant ivory on the surface web. Results were compared with known illegally traded items, specifically cannabis, cocaine and heroin. Of these 121 keywords, only four resulted in hits, of which only one was potentially linked to illegal wildlife trade. This sole case was the sale and discussion of Echinopsis pachanoi (San Pedro cactus), which has hallucinogenic properties. This negligible level of activity on the darkweb, compared to the open and burgeoning trade on the surface web, may indicate a lack of successful enforcement against illegal wildlife trade on the surface web, although other hypothesis are considered and explored.

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The study aimed to test the potential anthelmintic activity of Salix babylonica (SB) extract for the control of gastrointestinal and pulmonary parasites in sheep and goats under field conditions. A representative sample of 20 % of all animals reared in 8 sheep and 7 goat farms was used in the study. Animals from each farm were randomly selected for a total number of 93 sheep and 75 goats. Animals suffered a natural gastrointestinal nematode infection and had never been treated with chemical anthelmintic drugs. The SB extract (20 mL) was orally administered weekly before the morning feeding to each animal for 60 days. Fecal eggs or oocysts were counted at 0, 1, 20, 40, and 60 days after starting the extract administration. Differences (P < 0.01) in the fecal oocyst and egg output of Eimeria, Dictyocaulus, and Moniezia were observed between sheep and goats. In addition, the treatment influenced (P < 0.05) egg outputs of Cooperia, Dictyocaulus, and Trichuris. Fecal egg or oocyst counts of Haemonchus contortus, Eimeria, Cooperia, Chabertia, Dictyocaulus, Moniezia, and Ostertagia were time-dependent (P < 0.05). For sheep, administration of SB decreased (P < 0.05) the fecal eggs count of H. contortus, Cooperia, Chabertia, Dictyocaulus, Moniezia, and Trichuris. After 20 days of treatment, H. contortus, Cooperia, or Moniezia were not detected. For goats, SB reduced (P < 0.05) the fecal egg counts of H. contortus, Cooperia, Chabertia, and Moniezia. Moreover, decreases were observed (P < 0.05) for Chabertia, Trichostrongylus, and Ostertagia. Eggs of H. contortus and Moniezia were not present in the feces after 1 day of administration of the extract. It could be concluded that the weekly administration of SB extract at 20 mL per animal can be used to treat gastrointestinal and lung nematodes of small ruminants in organic and traditional farming systems of tropical regions.

Silvopastoral management strategies seek to expand spatial and temporal boundaries of forage production and promote ecosystem integrity through a combination of tree thinning and understory pastures. We determined the effects of water extracts of leaf litter from three species of overstory hardwood trees, yellow poplar, red maple, and white oak, on germination of common forage species: alfalfa, red and white clover, crabgrass, orchardgrass, and tall fescue without and with endophytes to increase understanding about potential interactions between silvopastures and overstory deciduous trees. Litter extracts reduced germination in red and white clover in a concentration dependent manner with greatest effects observed for poplar > maple > oak extracts. These reductions were linearly related to increasing osmolality and electrical conductivity of the leaf extracts. Modified Gompertz growth curve models, fit to data, further indicated treatment with litter extracts, especially poplar, delayed and slowed germination. Similarly, cumulative germination of a variety of grasses was inhibited by filtered 6 % (w/v) litter extracts with the effects of poplar > maple > oak. However, germination of all forages resumed after rinsing extract-treated seeds with water indicating inhibition could be due, in part, to osmotic effects of extracts or water-soluble allelopathic compounds. Final germination varied with forage species and extract type, but in most instances, did not reach the level of the control further suggesting specific ion toxicities as well. Management practices that account for the interactions between trees and forages are needed to ensure successful establishment and persistence of mixed species swards in silvopastoral systems.

Non Timber Forest Products play an important role as source of food and income generation in developing countries. In Burkina Faso, many wild tree species provide various useful products, among them the local oil tree, Lophira lanceolata which occurs in the western part of the country. This study aimed at assessing the habitat diversity and population structure of L. lanceolata’s natural stands according to land cover types. Two sites were considered: Banfora, where the use value of fruits is unknown and Orodara, where fruits are exploited for oil production. A stratified and oriented sampling scheme based on the occurrence of L. lanceolata and land cover was applied using rectangular plots of 50 m × 20 m. Phytosociological and quantitative inventories were carried out to assess the woody species diversity of stands and L. lanceolata population structure, respectively. Species diversity indices, structural parameters were computed and analyses of variance, Chi square test were performed to compare sites according to land cover types. The results showed high woody species diversity associated with L. lanceolata stands (H = 3.2–3.6). The densities of L. lanceolata ranged between 94 and 280 trees per hectare, with significant differences between land cover types and sites. The population pattern showed a good regeneration potential and high resource availability. L. lanceolata was fairly resilient to human pressure and tended to recolonize disturbed lands. With a high potential for sustainable management, L. lanceolata is a promising NTFP species which can contribute to improve the local and national economy.

Traditional agroecosystems are considered as main conservatories of landraces biodiversity because they preserve their dynamic processes and farmers’ knowledge of selection and management inherent in the development of local cultivars. The Mediterranean region still harbours traditional agroecosystems of particular importance for preserving crop biodiversity, being sweet chestnut (Castanea sativa Miller) a good example. This is one of the multipurpose species of most economic importance in the Mediterranean basin, cultivated extensively for fruit production, and the majority of varieties are the result of the selection of landraces by farmers. In this study, a set of European chestnut traditional varieties were evaluated in order to characterise its genetic resources and detect a possible response in the adaptive potential of this germplasm. Results of Bayesian analysis revealed a clear structure among cultivars from Italy and Spain with a low degree of admixture between them. Furthermore, a strong structure was detected within germplasm from each country congruent with their geographic origin. Statistical analyses did not reveal any significant marker deviating from neutral expectations. Results were discussed considering previous studies carried out on neutral and morphological markers, concluding that information provided by different markers was more powerful in detecting the maximum amount of genetic variation in chestnut varieties, and establishing a baseline to continue identifying markers underlying phenotypic differentiation and/or response to environmental cues among varieties.

Living snow fences (LSFs) are a cost-effective windbreak practice designed to mitigate blowing and drifting snow problems along transportation routes. Shrub-willows (Salix spp.) have been proposed as a LSF species to provide multiple benefits, given their potential to reach effective heights and densities soon after planting and provide a marketable biomass product. However, information regarding their establishment and snow storage capacity in LSF settings is limited. We investigated establishment and potential snow storage capacity of three shrub-willow varieties in LSF planting arrangements of two and four rows after one growing season post-coppice on a two-year-old root system in south-central Minnesota, USA. We found willows had an average survival of 89 %, an average height of approximately 1 m, and potential snow storage capacities ranging from 1 to 9 t m−1. Compared to the mean annual snow transport of the south-central region (39.9 t m−1), none of the willow LSF varieties and planting arrangements were able to trap all of the predicted blowing snow at the study site after two growing seasons post-coppice. However, using willow LSF models, we observed that willow LSFs could exceed local snow transport after 2–3 growing seasons post-coppice. Additionally, four-row willow LSF arrangements trapped approximately 20 % more snow than to two-row arrangements, and willow variety did not affect snow storage. These results add to the limited literature on shrub-willow LSFs and can guide the design of effective willow LSFs.

Programs and projects employing payments for ecosystem service (PES) interventions achieve their objectives by linking buyers and sellers of ecosystem services. Although PES projects are popular conservation and development interventions, little is known about their adherence to basic ecological principles. We conducted a quantitative assessment of the degree to which a global set of PES projects adhered to four ecological principles that are basic scientific considerations for any project focused on ecosystem management: collection of baseline data, identification of threats to an ecosystem service, monitoring, and attention to ecosystem dynamics or the formation of an adaptive management plan. We evaluated 118 PES projects in three markets—biodiversity, carbon, and water—compiled using websites of major conservation organizations; ecology, economic, and climate-change databases; and three scholarly databases (ISI Web of Knowledge, Web of Science, and Google Scholar). To assess adherence to ecological principles, we constructed two scientific indices (one additive [ASI] and one multiplicative [MSI]) based on our four ecological criteria and analyzed index scores by relevant project characteristics (e.g., sector, buyer, seller). Carbon-sector projects had higher ASI values (P < 0.05) than water-sector projects and marginally higher ASI scores (P < 0.1) than biodiversity-sector projects, demonstrating their greater adherence to ecological principles. Projects financed by public–private partnerships had significantly higher ASI values than projects financed by governments (P < 0.05) and marginally higher ASI values than those funded by private entities (P < 0.1). We did not detect differences in adherence to ecological principles based on the inclusion of cobenefits, the spatial extent of a project, or the size of a project's budget. These findings suggest, at this critical phase in the rapid growth of PES projects, that fundamental ecological principles should be considered more carefully in PES project design and implementation in an effort to ensure PES project viability and sustainability.

Una Valoración del Apego a los Principios Ecológicos Básicos por parte de Proyectos de Pagos por Servicios Ambientales

Los programas y los proyectos que emplean intervenciones de pagos por servicios ambientales (PSA) alcanzan sus objetivos al enlazar a los compradores y a los vendedores de los servicios ambientales. Aunque los proyectos de PSA son intervenciones populares de conservación y de desarrollo, se sabe poco sobre su apego a los principios ecológicos básicos. Realizamos una valoración cuantitativa del grado al cual un conjunto global de proyectos de PSA se apega a cuatro principios ecológicos que son consideraciones científicas básicas para cualquier proyecto enfocado en el manejo de ecosistemas: colecta de datos de línea base, identificación de amenazas para un servicio ambiental, monitoreo y atención a las dinámicas del ecosistema o a la formación de un plan de manejo adaptativo. Evaluamos 118 proyectos de PSA en tres mercados – biodiversidad, carbono y agua – recopilados con el uso de los sitios web de las mayores organizaciones de conservación, bases de datos ecológicos, económicos y de cambio climático, y tres bases de datos de expertos (ISI Web of Knowledge, Web of Science y Google Scholar). Para valorar el apego a los principios ecológicos construimos dos índices científicos (uno aditivo [ICA] y uno multiplicativo [ICM]) con base en nuestros cuatro criterios ecológicos y analizamos los puntajes de índice por características de proyecto relevante (es decir, sector, comprador, vendedor). Los proyectos del sector-carbono tuvieron valores ICA más altos (P < 0.1) que los proyectos del sector-biodiversidad, lo que demuestra su mayor apego a los principios ecológicos. Los proyectos financiados por asociaciones público-privadas tuvieron valores ICA más altos que los proyectos financiados por el gobierno (P < 0.05) y valores ICA marginalmente más altos que aquellos financiados por entidades privadas (P < 0.1). No detectamos diferencias en el apego a los principios ecológicos basadas en la inclusión de co-beneficios, la extensión espacial de un proyecto o el tamaño del presupuesto de un proyecto. Estos descubrimientos sugieren, en esta fase crítica del crecimiento rápido de los proyectos de PSA, que los principios ecológicos fundamentales deberían ser considerados con mayor cuidado en el diseño y en la implementación de proyectos de PSA como un esfuerzo por asegurar la viabilidad y sustentabilidad de los proyectos de PSA.

Agroforestry is known to have multiple economic and environmental benefits. Despite this, the adoption of agroforestry in Viet Nam is limited both in extent and diversity of components and practices. Our study identified gaps for agroforestry adoption in current policies and policy implementation. National policy and provincial instructions and decisions were reviewed and discussed during ten stakeholders’ consultation workshops. The review and workshops concluded that there were no specific national and few provincial specific policies promoting agroforestry. In addition, the segregation of policies into agriculture and forestry, promoted monoculture practices and discouraged the integration of mixed annual and perennial tree species. Completing the forestland allocation process was considered essential for long-term investment on land and providing collateral for loans. More holistic policies, such as a provincial strategy for agroforestry development that would enable flexible integration of agriculture, forestry and livestock were perceived to be more effective and inclusive to poor and non-poor farmers. Specific cross-cutting budget allocation would be necessary for capacity building, upscaling agroforestry models, procurement of high-quality inputs, and establishing post-harvest processing and marketing investments.

The role of citizen science in research and natural resource monitoring and management is increasing, as evidenced by the growing number of peer-reviewed publications (including a special section in this journal) and calls for involving citizens in monitoring and governance (through, for example, “participatory research” [Danielsen et al. 2014] and “participatory monitoring” [Kennett et al. 2015]). Citizen science projects can be targeted to a specific research question (and thus involve very specific data-collection protocols) or can be more open-ended (giving rise to a need to collect data for which the uses may be unknown or changing) (Wiersma 2010). Advances in online content production and sharing technologies (i.e., Web 2.0), mobile computing, and sensor-equipped devices have contributed to a dramatic rise in online citizen science projects, in which citizens contribute sightings (e.g., eBird [Sullivan et al. 2009]), transcribe data (e.g., Old Weather [Eveleigh et al. 2013]), or classify phenomena (e.g., Galaxy Zoo [Hopkin 2007]). It is these online projects, also referred to as crowdsourcing (Franzoni & Sauermann 2014), that have been the focus of our research and that inform the opinions presented here.

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