Browsing by Author "Mbogga, Michael S."

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    Assisted migration to address climate change: recommendations for aspen reforestation in western Canada
    (Ecological applications, 2011) Gray, Laura K.; Gylander, Tim; Mbogga, Michael S.; Chen, Pei-Yu; Hamann, Andreas
    Human-aided movement of species populations in large-scale reforestation programs could be a potent and cost-effective climate change adaptation strategy. Such largescale management interventions, however, tend to entail the risks of unintended consequences, and we propose that three conditions should be met before implementing assisted migration in reforestation programs: (1) evidence of a climate-related adaptational lag, (2) observed biological impacts, and (3) robust model projections to target assisted migration efforts. In a case study of aspen (Populus tremuloides Michaux.) we use reciprocal transplant experiments to study adaptation of tree populations to local environments. Second, we monitor natural aspen populations using the MODIS enhanced vegetation index as a proxy for forest health and productivity. Last, we report results from bioclimate envelope models that predict suitable habitat for locally adapted genotypes under observed and predicted climate change. The combined results support assisted migration prescriptions and indicate that the risk of inaction likely exceeds the risk associated with changing established management practices. However, uncertainty in model projections also implies that we are restricted to a relatively short 20-year planning horizon for prescribing seed movement in reforestation programs. We believe that this study exemplifies a safe and realistic climate change adaptation strategy based on multiple sources of information and some understanding of the uncertainty associated with recommendations for assisted migration. Ad hoc migration prescriptions without a similar level of supporting information should be avoided in reforestation programs.
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    Bioclimate envelope model predictions for natural resource management: dealing with uncertainty
    (Journal of Applied Ecology, 2010) Mbogga, Michael S.; Wang, Xianli; Hamann, Andreas
    Bioclimate envelope models are widely used to predict the potential distribution of species under climate change, but they are conceptually also suitable to match policies and practices to anticipated or observed climate change, for example through species choice in reforestation. Projections of bioclimate envelope models, however, come with large uncertainties due to different climate change scenarios, modelling methods and other factors. 2. In this paper we present a novel approach to evaluate uncertainty in model-based recommendations for natural resource management. Rather than evaluating variability in modelling results as a whole, we extract a particular statistic of interest from multiple model runs, e.g. species suitability for a particular reforestation site. Then, this statistic is subjected to analysis of variance, aiming to narrow the range of projections that practitioners need to consider. 3. In four case studies for western Canada we evaluate five sources of uncertainty with two to five treatment levels, including modelling methods, interpolation type for climate data, inclusion of topo-edaphic variables, choice of general circulation models, and choice of emission scenarios. As dependent variables, we evaluate changes to tree species habitat and ecosystem distributions under 144 treatment combinations. 4. For these case studies, we find that the inclusion of topo-edaphic variables as predictors reduces projected habitat shifts by a quarter, and general circulation models had major main effects. Our contrasting modelling approaches primarily contributed to uncertainty through interaction terms with climate change predictions, i.e. the methods behaved differently for particular climate change scenarios (e.g. warm&moist scenarios) but similar for others. 5. Synthesis and applications. Partitioning of variance components helps with the interpretation of modelling results and reveals how models can most efficiently be improved. Quantifying variance components for main effects and interactions among sources of uncertainty also offers researchers the opportunity to filter out biologically and statistically unreasonable modelling results, providing practitioners with an improved range of predictions for climate-informed natural resource management.
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    Carbon stock of Agoro Agu Central Forest Reserve, in Lamwo District, Northern Uganda
    (Research Square, 2022) Birungi, Vicent; Workeneh-Dejene, Sintayehu; Mbogga, Michael S.; Dumas-Johansen, Marc
    Uganda has since not undertaken carbon stock inventories for these conservation areas, especially with dry Afromontane forests like Agoro-agu central forest reserve (CFR). This study was carried out to estimate carbon stock of Agoro-agu CFR, for its potential in climate change mitigation. A stratified sampling design was used, where 65 sample plots were established. Nested, fixed area circular sample plots with sub-plots of varying radii for tree height, diameter measurements and soil sampling. The mean total carbon stock of Agoro-agu CFR was estimated at 606.7 mg ha-1, for which 409, 72, 124 and 0.24 mg ha-1 was stored as above ground carbon, below ground carbon, soil organic carbon and carbon in litter herbs and grass respectively. The study illustrates the carbon sequestration potential of the forest for any results-based payment projects for climate change mitigation, which calls for multi-stakeholders’ collaboration from direct resource users to national level to enhance forest conservation and reduce forest degradation.
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    Expansion of Commercial Sugarcane Cultivation among Smallholder Farmers in Uganda: Implications for Household Food Security
    (Land, 2018) Mwavu, Edward N.; Kalema, Vettes K.; Bateganya, Fred; Byakagaba, Patrick; Waiswa, Daniel; Enuru, Thomas; Mbogga, Michael S.
    Understanding the impact of commercial agriculture in the face of global change is critical to support strategies that ensure food security and alleviate poverty among households. We assessed the contribution of commercial sugarcane cultivation to household-level food security among smallholder farmers in Busoga sub-region, eastern Uganda. Land use changes are motivated by quick commercial gains rather than sustained food production; a situation that influences food security. The majority of households cultivate few crop varieties, lack adequate and nutritious foods, and have inadequate income to purchase food to meet their needs. Inadequacy of food within some commercial sugarcane-cultivating households suggests that generating income does not necessarily increase food security. To cope with food insecurity, households offer labour in exchange for food, borrow food, ration food, and at times steal. This is exacerbated by increasing food crop failures, large family sizes, trade in food items, and declining availability of food and land for food production. Commercial sugarcane cultivation is the main driver of food insecurity but given its perceived economic benefits, future sugarcane plantations expansion in the region is probably inevitable. Therefore, future policy should be designed to provide triple-win strategies (i.e., food security, poverty alleviation, and climate change adaptation) that provide sustainable livelihoods.
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    Gender differentiated vulnerability to climate change in Eastern Uganda
    (Climate and Development, 2019) Balikoowa, Kenneth; Nabanoga, Gorettie; Mwesigye Tumusiime, David; Mbogga, Michael S.
    Climate change literature is rife with the assertion that women are more vulnerable to climate change, which state is expected to reflect on female-headed households. However, this assertion has however not been empirically proven aside from the general poverty-gender linkages. This study used primary data collected in 2016 from 735 randomly selected households from four districts in Eastern Uganda to construct a gender vulnerability index to compare and explain the drivers of vulnerability between male and female-headed households. The results show that female-headed households were more vulnerable (GVI-IPCC = −0.134) than male-headed households (GVI-IPCC = −0.176). The results further show that disparity in adaptive capacity mediates vulnerability between male and female-headed households. This underscores the importance of proactive interventions rather than protectionist approaches to reducing vulnerability. The study has extended the analytical utility of the livelihood vulnerability index to create a gender vulnerability index for comparing contextual groups of households in Eastern Uganda.
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    Historical and projected climate data for natural resource management in western Canada
    (Agricultural and forest meteorology, 2009) Mbogga, Michael S.; Hamann, Andreas; Wang, Tongli
    In this paper we present a comprehensive set of interpolated climate data for western Canada, including monthly data for the last century (1901–2006), future projections from general circulation models (68 scenario implementations from 5 GCMs), as well as decadal averages and multiple climate normals for the last century. For each of these time periods, we provide a large set of basic and derived biologically relevant climate variables, such as growing and chilling degree days, growing season length descriptors, frost free days, extreme minimum temperatures, etc. To balance file size versus accuracy for these approximately 15,000 climate surfaces, we provide a stand-alone software solution that adds or subtracts historical data and future projections as medium resolution anomalies (deviations) from the high resolution 1961–1990 baseline normal dataset. For a relative quality comparison between the original normal data generated with the Parameter Regression of Independent Slopes Model (PRISM) and derived historical data, we calculated the amount of variance explained (R2) in original weather station data for each year and month from 1901 to 2006. R2 values remained very high for most of the time period covered for most variables. Reduction in data quality was found for individual months (as opposed to annual, decadal or 30-year climate averages) and for the early decades of the last century. We discuss the limitations of the database and provide an overview of recent climate trends for western Canada.
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    Stalk-eyed fly, Diopsis sp. population dynamics under varying temperature and Relative Humidity in rice ecosystems
    (2018) Kayongo, Charles; Mbogga, Michael S.; Goncalves de Abreu, Aluana; Masika, Fred; Masanza, Michael; Freitas Barrigossi, Jose Alexandre; Kizito, Elizabeth B.
    Although the stalk-eyed fly (Diopsis sp.) has been observed in Ugandan rice fields, there is limited information on the fly’s population and its potential threat to rice production. This study assessed the stalk-eyed fly (Diopsis longicornis and Diopsis apicalis) population dynamics under varying temperature and relative humidity in rice ecosystems of Uganda. It was conducted in purposively selected small scale rice farming sub-counties in low land rain fed and irrigated rice agro-ecologies (Lake Victoria Crescent, Kasese transition zone and Northern moist farmlands). Diopsis sp. populations were monitored by sampling rice fields every 40 days for a period of 17 months. Weather parameters including air temperature and humidity were recorded by use of data loggers throughout the study period. R-statistical tool and MS Excel were used to assess the population dynamics and interactions of the diopsids. D. longicornis fly was dominantly abundant in rice fields of Lake Victoria Crescent and Northern Moist zones while D. apicalis was dominant in Kasese transition zone. There was significant mean count variations per survey for both species in all the agro-ecological zones with P-values of 0.000958 (D. longicornis) and 1.12e-12 (D. apicalis) in Lake Victoria crescent, 0.000473 (D. apicalis) and 0.0173 (D. longicornis) in Northern moist farmlands, 0.0188 (D. apicalis) and 0.0353 (D. longicornis) in Kasese transition zone. Temperature and relative humidity had a direct effect on the population of both species in Northern moist zone and only on D. apicalis in Kasese transition zone. The optimum/favorable temperatures for abundance were between 27oC and 29oC. Interpretation of the results? Integrated pest management strategies and introduction of improved Diopsis pest resistant rice varieties are some of the recommendations for managing the stalk-eyed fly populations in these rice ecosystems.