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Adaptive management is a systematic approach for linking learning with implementation to facilitate ongoing improvement in natural resource management. The idea of learning from experience and adapting subsequent policies, strategies and actions, is intuitively appealing. However, application of adaptive management has been hindered by several obstacles, including a paucity of documented lessons from existing adaptive management practices and inadequate attention to the complex social aspects of learning. Here we address these two impediments through (i) a case study of an established version of adaptive management and its application in the context of protected area management plans, and (ii) its critical comparison and conceptual integration with the seminal theory of organizational knowledge creation (TOKC), which emphasizes the social aspects of learning. As case study, we focus on Strategic Adaptive Management (SAM), which has been iteratively developed and implemented by South African National Parks for more than 20 years. We used TOKC as a conceptual sounding board to reflect on and appraise the learning that takes place through SAM. A comparison of the main steps of the SAM cycle with corresponding stages outlined by TOKC revealed remarkable complementarity between these two approaches, but also important differences. The conceptual comparison deepened our understanding of SAM's learning performance as well as potential, revealing strengths, weaknesses and opportunities for improvement. Key insights include that valuable and different forms of learning takes place during each step of the SAM cycle. This learning can be enhanced through careful attention to approaches for creating, sharing and making explicit the tacit knowledge of individuals. Furthermore, dialogue and co-learning with stakeholders should be maintained beyond the visioning and objectives setting step of SAM. Based on insights gained, we developed a new and complementary conceptualization of SAM, as a spiraling process of organizational learning enabled by the interplay between tacit and explicit forms of knowledge, which in turn is mediated by different types of social interactions, media and engagement with practice. We believe that this conceptualization can help to better acknowledge and enable learning as one of the most fundamental purposes and outcomes of SAM, and adaptive management more generally.
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Conocimiento , Organizaciones , HumanosRESUMEN
The idea that noncrop habitat enhances pest control and represents a win-win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win-win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
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Productos Agrícolas , Ecosistema , Modelos Biológicos , Control Biológico de Vectores , Animales , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/parasitologíaRESUMEN
Honeybees (Apis mellifera L.) have great potential for detecting and monitoring environmental pollution, given their wide-ranging foraging behaviour. Previous studies have demonstrated that concentrations of metals in adult honeybees were significantly higher at polluted than at control locations. These studies focused at a limited range of heavy metals and highly contrasting locations, and sampling was rarely repeated over a prolonged period. In our study, the potential of honeybees to detect and monitor metal pollution was further explored by measuring the concentration in adult honeybees of a wide range of trace metals, nine of which were not studied before, at three locations in the Netherlands over a 3-month period. The specific objective of the study was to assess the spatial and temporal variation in concentration in adult honeybees of Al, As, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, Ti, V and Zn. In the period of July-September 2006, replicated samples were taken at 2-week intervals from commercial-type bee hives. The metal concentration in micrograms per gram honeybee was determined by inductive coupled plasma-atomic emission spectrometry. Significant differences in concentration between sampling dates per location were found for Al, Cd, Co, Cr, Cu, Mn Sr, Ti and V, and significant differences in average concentration between locations were found for Co, Sr and V. The results indicate that honeybees can serve to detect temporal and spatial patterns in environmental metal concentrations, even at relatively low levels of pollution.
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Abejas/metabolismo , Contaminantes Ambientales/metabolismo , Metales Pesados/metabolismo , Animales , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Contaminación Ambiental/estadística & datos numéricos , Metales Pesados/análisis , Países BajosRESUMEN
Sustainability indicators have become essential tools to deal with compartmentalized resources planning and management in cities. The development of water, energy, and food nexus (WEF nexus) indicators is a prominent goal of current research, but the focus is mainly on economic issues and material flows. Attention to the local scale and context, social aspects, and the inclusion of non-academic actors is mostly lacking. To address these gaps, this paper reports and reflects on the co-creation of sustainability indicators related to the WEF nexus in the city of São Paulo, Brazil. With a transdisciplinary approach, non-academic actors were included in the different stages of the process using the Urban Living Lab methodology, to improve the usability of the produced indicators' set. The case of São Paulo concerned on-going actions in the peri-urban and rural areas of the city which seek to improve environmental protection by stimulating more sustainable forms of agriculture. Thirty-four indicators were developed through a sequence of interactive activities, such as workshops, meetings, and field trips. The presented process aims to strongly enhance usability by actively involving users from the start, connecting the nexus approach to previous knowledge and familiar frameworks, paying attention to the local scale and context, and to social aspects, and by anticipating future use in various ways.
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We conducted a study to assess to what extent current ecolabels contain standards that stimulate conservation and sustainable use of on-farm biodiversity of agricultural landscapes (agrobiodiversity). First, we developed an agrobiodiversity management yardstick to assess and compare the labeling schemes of ecolabels for arable farming. Key characteristics of the yardstick are the five levels linking the abstract notion of agrobiodiversity management to concrete measures on a farm and its foundation upon expert judgment regarding the effect of farming practices on agrobiodiversity. Several environmental themes, among them agrobiodiversity management, are regulated through the standards of labeling schemes of ecolabels. With the aid of this yardstick, the labeling schemes were scrutinized and the number, average efficacy, and compulsory nature of relevant standards was determined for 10 categories of farm management. The results show that all examined ecolabels contain at least some standards that stimulate conservation and sustainable use of agrobiodiversity, but there are large differences between the labels. We consider the results of the five ecolabels to be insufficient to warrant their usefulness as a governance strategy that the Dutch government could refer to and depend on as part of a national agrobiodiversity policy to stimulate agrobiodiversity.
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Agricultura/normas , Biodiversidad , Ecología , Agricultura/métodos , Conservación de los Recursos NaturalesRESUMEN
Immobilized preys are routinely used in agro-ecological exposure studies to quantify predation of pests under field conditions, but this method has not been validated. Our purpose was to determine the validity of using immobilized adults of the major rice pest Nilaparvata lugens, brown plant hopper (BPH), as sentinels. We used direct observation by video recording to determine the causal agents of removal of field exposed BPH sentinels with two experiments: 1) we recorded removal events of dead, immobilized BPH; and 2) we compared removal of (i) dead, immobilized BPH, (ii) live, immobilized BPH, and (iii) live, mobile BPH. Long-horned grasshoppers were responsible for most removals of dead, immobilized BPH, in both experiments. Predatory ground beetles removed most of the live, immobilized BPH, whereas frogs were the major predators of live, mobile BPH. Overall, we showed that removal of immobilized sentinel prey is not representative for predation of live, mobile prey, stressing the need for a critical assessment of commonly used sentinel methods. In addition, we found that frogs played the major role in predation of BPH in rice. As current strategies to enhance biocontrol of planthoppers in rice focus on arthropod natural enemies, this finding could have major implications.
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Hemípteros/fisiología , Oryza/parasitología , Conducta Predatoria/fisiología , Grabación en Video , Animales , Conducta Alimentaria , FilogeniaRESUMEN
Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m(2) yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries.