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Forest biomass harvest has the potential to provide feedstocks for energy production to offset fossil fuel consumption. However, concerns have been raised regarding the ecological sustainability of removing additional biomass from forests, in particular the impacts on biodiversity. In this paper, we used a suite of ground-dwelling arthropod taxa (ground beetles, spiders, and rove beetles) to measure community compositional changes along a gradient of biomass removal treatments 7 years postharvest, and compared against reference. Based on multivariate regression trees, changes in species composition reflected the intensity gradient of the biomass removal treatments or stand attributes associated with the level of forest floor disturbance across all arthropod groups. For each arthropod group, changes in composition were defined primarily by reductions or loss of abundant forest associated species and increases in the number and abundance of species associated with more xeric conditions and increased disturbance intensity. There were no differences between full-tree and tree-length treatments. Overall, results indicated a strong arthropod response to the removal of overstory, forest floor disturbance, and reductions in understory cover mostly resulting from the glyphosate applications. Arthropod recovery would benefit from overstory retention, reduction in forest floor disturbance, and judicious use of glyphosate. Key words: biomass harvesting, glyphosate, Carabidae, spiders, Staphylinidae, 1. Introduction Recovery of residual forest biomass from harvesting operations, including branches, unmerchantable tree-tops, and even stumps, may provide an additional source of renewable energy and reduce reliance on fossil [...]

For many of the world's fisheries, harvest control rules (HCRs) are the main tools for supporting decision-making. We previously clarified the optimal shape of the HCR to achieve multiple fisheries management objectives (maximising average catch, reducing variation in yields, and avoiding stock collapse) and ensure robustness to estimation errors in biomass by numerically estimating the optimal values of the 21 biological reference points (BRPs) comprised in the HCR. However, for actual management, a simple but comprehensive functional form to emulate the optimal HCR is desirable, as numerical HCR optimisation with many BRPs is time-consuming. Here, we introduced three objective utility functions (U1-U3) representing HCR performance for composite management objectives: mean-variance utility functions, where the performance indicator for variation in yields is the standard deviation (U1) or the annual average variance (U2) of yields, and the constant relative risk aversion utility function (U3). We derived two equations to emulate the optimal HCRs with three adjusting parameters corresponding to the management objectives and different magnitudes of estimation errors. These equations will help stakeholders discuss desired management strategies by showing expected catch and risk by adjusting the parameter values. Key words: bio-economics, fishery management objective, harvest control rule, management strategy evaluation, utility function, 1. Introduction To realise a sustainable society, wide-ranging problems need to be solved. In 2015, the United Nations adopted the Sustainable Development Goals (SDGs), comprising 17 goals and 169 targets, [...]

In this study, a multispecies gadget model (GadCap) simulating the interactions among the Flemish Cap cod (Gadus morhua), redfish (Sebastes spp.), and shrimp (Pandalus borealis) has been incorporated as the operating model in a management strategy evaluation (MSE) framework (a4a-FLR) to test the performance of multiple combinations of harvest control rules (HCRs) for the three stocks when recruitment uncertainty and assessment error are accounted for. The results indicate that due to the strong trophic interactions, it is not possible to achieve the precautionary exploitation of all the stocks at the same time. Maintaining shrimp biomass above the limit reference point ([B.sub.lim]) would require unsustainable fishing pressure on cod and redfish to reduce predation mortality. In contrast, maintaining cod biomass above [B.sub.lim] would involve high predation on and high risk of collapse of the shrimp and redfish stocks. The implementation of alternative two-stage HCRs would reduce predation, resulting in higher productivity and lower probability of collapse for cod and redfish. The results of this study support the need of accounting for species interactions when designing management strategies for a group of interdependent commercial stocks. Un modele multi-especes Gadget (GadCap) qui simule les interactions de la morue (Gadus morhua), des sebastes (Sebastes spp.) et de la crevette nordique (Pandalus borealis) sur le bonnet Flamand a ete integre comme modele d'exploitation dans un cadre (a4a-FLR) devaluation de strategies de gestion (ESG) afin de valider la performance de differentes combinaisons de regles de controle des prises (RCP) pour les trois stocks quand l'incertitude reliee au recrutement et l'erreur d'evaluation sont prises en compte. Les resultats indiquent que, en raison des fortes interactions trophiques, l'atteinte de l'exploitation prudente simultanee de tous les stocks n'est pas possible. Le maintien d'une biomasse de crevette superieure au point de reference limite ([B.sub.lim]) necessiterait une pression de peche a la morue et aux sebastes non durable pour reduire la mortalite par predation. Le maintien de la biomasse de morue au-dessus du [B.sub.lim] necessiterait quant a lui une forte predation et un risque eleve d'effondrement des stocks de crevette et de sebastes. L'application de differentes RCP en deux volets reduirait la predation, entrainant une productivite accrue et une plus faible probabilite d'effondrement de la morue et des sebastes. Les resultats de l'etude soulignent la necessite de tenir compte des interactions d'especes dans la conception de strategies de gestion pour un groupe de stocks commerciaux interdependants. [Traduit par la Redaction], Introduction Traditional approaches to fisheries management consider species exploited in the same ecosystem as if they were completely independent (i.e., a single-species approach) when defining reference points, harvest control rules [...]

Nightshade (Solanum species) is a priority African indigenous vegetable of great importance that plays a significant role in nutrition, food security and income generation. Much research attention on nightshade has focused on leaf yields, nutritional value, agronomic practices and post-harvest handling. However, African nightshade production is mainly constrained by lack of quality seeds occasioned by methods of seed harvesting, processing and storage. This study sought to find out existing knowledge on methods of seed harvesting, processing and storage techniques and their associations with farmers' characteristics. A household survey was done in Siaya, Kakamega, Vihiga, Kisumu, Busia and Kisii counties in Kenya between June 2014 and June 2015. The survey targeted farmers who produced and processed nightshade seeds in a bid to document existing methods of nightshade seed harvesting, processing and storage techniques. Purposive sampling was conducted on the targeted counties so as to survey only households that grow and process nightshade seeds. Scheduled interviews together with structured questionnaires were used to collect data. A total of 60 farmers were interviewed. Data were collected on nightshade production, cultural practices, harvesting processing and storage techniques, seed accessibility and availability, seed quality, quantity, cost and the challenges facing the nightshade seed production. Data collected were subjected to descriptive statistics using Statistical Package for Social Sciences (SPSS) version 21. Significantly more women were involved in nightshade seed production than men (X2= 4.81, P = 0.028). While, the level of education of farmers significantly influenced seed sourcing (X2 = 17.99, P = 0.021), the age and sex of farmers did not affect seed sourcing. The choice of methods used for nightshade seed extraction was not significantly associated with age, sex and the level of education. Similarly, nightshade seed packaging and storage techniques are not influenced by age, sex and level of education. Nightshade seed processing techniques were predominantly traditional and the seed systems informal. Farmers produced their own seeds and stored them for periods of less than one year. Therefore, farmers should be trained on production, storage and use of quality African nightshade seeds and more studies that focus on improvement, standardising and formalizing nightshade seed systems should be done.Key words: Indigenous vegetables, Nightshade seeds, Production, Harvesting, Processing, Storage techniques, Seed systems, INTRODUCTIONAfrican nightshade (Solanum spp.) is a group of African Indigenous Vegetable (AIV) species that are cultivated and consumed in many parts of sub-Saharan Africa especially in Eastern, Western and Southern [...]

The Washington State Department of Natural Resources (DNR) manages over 800,000 hectares of forested state trust lands and 20,000 kilometers of forest roads in Washington State. Forest harvest and road reconstruction decisions greatly impact the agency's cash flows and its ability to meet its fiduciary obligations. We introduce a mixed-integer programming model that integrates harvest and road scheduling decisions. We show how DNR embedded the new model in its workflows and applied it to the Upper Clearwater River Landscape in the Olympic Experimental State Forest. We find that the forest valuation of the Upper Clearwater increased by $0.5-$l million (0.4-1.1 percent) because of the new method, which allowed the DNR to concentrate capital expenditures in support of harvest and road operations in both time and space. This led to a 14.5 percent reduction in the size of the active road network. DNR is now in the process of scaling the new approach to the entire forest estate. History: This paper was refereed. Funding: This study was funded by the Washington State Department of Natural Resources. Keywords: integer * forestry * transportation: road * scheduling * natural resources, Introduction Forest roads are an integral, yet expensive, component of forestry (Greulich 2002). They also increase the risk of wildfires, sediment delivery (Bowker et al. 2010, Bettinger et al. 1998, [...]