Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2024
Forfattere
Belachew Gizachew Zeleke Deo D. Shirima Jonathan Rizzi Collins Byobona Kukunda Eliakimu ZahabuSammendrag
Tanzania dedicates a substantial proportion (38%) of its territory to conservation, with a large number of Protected Areas (PAs) managed under various regimes. Nevertheless, the country still experiences high rates of deforestation, which threaten the ecological integrity and socio-economic benefits of its forests. We utilized the Global Forest Change Dataset (2012–2022) and implemented a Propensity Score Matching (PSM) approach followed by a series of binomial logit regression modeling. Our objectives were to evaluate (1) the likelihood of PAs in avoiding deforestation compared with unprotected forest landscapes, (2) the variability in effectiveness among the different PA management regimes in avoiding deforestation, (3) evidence of leakage, defined here as the displacement of deforestation beyond PA boundaries as a result of protection inside PAs. Our findings reveal that, despite ongoing deforestation within and outside of PAs, conservation efforts are, on average, three times more likely to avoid deforestation compared with unprotected landscapes. However, the effectiveness of avoiding deforestation significantly varies among the different management regimes. National Parks and Game Reserves are nearly ten times more successful in avoiding deforestation, likely because of the stringent set of regulations and availability of resources for implementation. Conversely, Nature Forest Reserves, Game Controlled Areas, and Forest Reserves are, on average, only twice as likely to avoid deforestation, indicating substantial room for improvement. We found little evidence of the overall leakage as a consequence of protection. These results highlight the mixed success of Tanzania’s conservation efforts, suggesting opportunities to enhance the effectiveness of many less protected PAs. We conclude by proposing potential strategic pathways to enhance further the climate and ecosystem benefits of conservation in Tanzania.
Forfattere
Gunda ThömingSammendrag
Conservation biological control (CBC) is a sustainable measure for ecological intensification in agriculture to establish and maintain robust natural enemy populations. CBC is contributing to integrated pest management with reduced use of pesticides and support of native biodiversity in agroecosystems. Despite rapidly expanding research on CBC during the last decades, its application in pest management at the farm level is very limited. Here, we tested a CBC strategy in a 5-year on-farm study at three locations in East Norway. This CBC strategy combined two tools to increase biological control of aphids in spring barley; 1-ATTRACT, the application of a volatile organic compound (VOC) attractant that increases lacewing egg laying, and 2-HABITAT, the maintenance of natural border vegetation. We found that the VOC attractants recruited natural enemies and guided them to the right place at the right time from the border vegetation into the cropping area to control the aphid population efficiently and reliably. The results also showed that the VOC attractants combined with periodical maintained natural border vegetation provided a higher lacewing activity and aphid suppression than with annual sown floral buffer strips. We found that maintained natural border vegetation supported by VOC attractants provided lacewing populations that controlled aphids up to 100 m into the cropping area. Without VOC attractants we recorded lacewing activity up to 50 m from the border into the cropping area if natural border vegetation was available, and up to 25 m if no border vegetation existed. The overall results demonstrated the feasibility of this CBC approach under Norwegian farming conditions leading to the successful adoption of this CBC-strategy by the farming community.
Sammendrag
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Sammendrag
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Sammendrag
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Forfattere
Rasmus Bang Bjørn Gunnar Hansen Mario Guajardo Jon Kristian Sommerseth Ola Flaten Leif Jarle AsheimSammendrag
CONTEXT An important question for farmers is whether to run their farm conventionally or organically. This choice can significantly affect the farm's financial performance and its impact on the environment. OBJECTIVE The primary objective of this study is to compare the profitability of conventional and organic cattle systems and investigate how it is associated with individual farm characteristics, like forage production capacity, forage quality, milk quota, animal housing capacity, and their relative presences. METHOD We employ a whole farm optimization model, customized for Norwegian cattle farming. The primary goal of this model is to maximize the gross margin by optimizing decisions related to land usage and animal inventory while adhering to a set of constraints. We systematically solve more than 200,000 model instances, with varying farm characteristics. RESULTS AND CONCLUSIONS The results can be distilled to the following key points: If forage of good quality is readily available, but the livestock operation cannot be expanded due to animal housing and milk quota restrictions, organic may outcompete conventional farming. Otherwise, gross margin is maximized with conventional farming. These findings emphasize the crucial role of forage production capacity and quality in relation to available milk quota and infrastructure when considering the transition from conventional to organic farming. Extensive sensitivity analyses affirm the robustness of these conclusions. Regional regulatory factors, such as government farm payments, also play a significant role, and influence the optimal farming approach. Additionally, we show that increases in organic price premiums can markedly impact the competitiveness of organic farming, even in a system where government payments make out a significant part of the farm revenue. SIGNIFICANCE The model can support farmers to make informed decisions about converting to organic or conventional farming. It can also be used by policymakers to determine the level of support required to make it worthwhile for different types of farms to convert. We also show that existing government payment schemes give rise to regional differences in the incentives for organic farming in Norway. To ensure equal incentives for organic farming across the country, the organic payments would have to be regionally adjusted, in line with the other already regionally dependent government payments. This insight may be of significant interest to policymakers and other stakeholders.
Forfattere
Mario Guajardo Rasmus Bang Leif Jarle Asheim Ola Flaten Bjørn Gunnar Hansen Jon Kristian SommersethSammendrag
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Forfattere
Mario Guajardo Rasmus Bang Leif Jarle Asheim Ola Flaten Bjørn Gunnar Hansen Jon Kristian SommersethSammendrag
Interest for organic products and concerns regarding sustainable practices raise an important question for farmers: should they run their farms conventionally or organically? We address this question by means of a mathematical programming model, which aims to optimize gross margin of cattle farms. We implement the model using data from Norway, including government support stipulations and a number of other features. A computational study allows us to assess the economic performance of organic farming compared to conventional farming systems. We derive some insights into the conditions when organic outperforms conventional systems, and vice versa. These hold significant relevance not only to farmers, but also to farm advisors and policy makers.
Sammendrag
The aim was to determine the growth of pollen tubes throughout the transmitting tissue and the process of fertilization in open, optimal and over pollination on the 3rd, 6th and 9th day after pollination of pistillate flowers, together with apomixis. The experiment was carried out over 2 years in Lovasberény, Fejér district, Hungary, which differed in temperature conditions. The average number of pollen tubes in the locule of the ovary was significantly higher in 2017 (1.3%) than in 2019 (1%). A higher percentage of fruit set was recorded in 2017 compared to 2019. The percentage of apomictic fruits from variant of unpollination was higher in 2017 (10%) than in 2019 (3.7%). Based on these results it can be concluded that pollen tube growth and post-fertilization processes together with apomixis of cultivar ‘AK’ are better adaptable to lower temperatures. These findings may help us to move walnut production to the north or to higher altitudes, where the climate is more continental.
Forfattere
Abirami Ramu Ganesan Kannan Mohan Sabariswaran Kandasamy Ramya Preethi Surendran Ragavendhar Kumar Durairaj Karthick Rajan Jayakumar RajarajeswaranSammendrag
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