| 1. |
- Beche, Dinkissa, et al.
(författare)
-
Prevalence of major pests and diseases in wild and cultivated coffee in Ethiopia
- 2023
-
Ingår i: Basic and Applied Ecology. - 1439-1791 .- 1618-0089. ; 73, s. 3-9
-
Tidskriftsartikel (refereegranskat)abstract
- The study of pests and diseases on crops and crop relatives in the wild is valuable from both a theoretical and an applied point of view. Few studies have addressed multiple pests and diseases in such ecosystems. Our objectives were to (1) compare the prevalence of multiple pests and diseases on coffee in forests and more managed landscapes and (2) assess how spatial, environmental, host density and management factors affect the incidence and severity of coffee pests and diseases across forests.To achieve these objectives we studied different pests, diseases and one hyperparasite on wild and semi-wild coffee from 84 plots of 20 × 20 m across a forested landscape in southwest Ethiopia and compared the results to previous studies of more intensively managed adjacent landscapes.The prevalence of all surveyed coffee leaf pests and diseases was high (>71% of investigated plots) and very similar to the levels in more intensively managed landscapes reported in the literature. The incidence rates of all pests, diseases and the hyperparasite showed a high variation among the plots, and correlation with each other in some cases. However, this variation was weakly related to the measured environmental and management variables, but coffee pests and diseases were often positively related to high coffee density.One possible explanation for the similar prevalence is that, although the landscapes are different, the local environmental conditions have much in common since coffee is also grown under indigenous shade trees in more intensively managed landscapes. However, the variability in pest and disease levels among sites was large and it is difficult to predict where they attain high levels. There is a need of detailed investigations on drivers of spatio-temporal population dynamics of these species, including their natural enemies, to be able to provide advice for development of sustainable coffee disease management.
|
|
| 2. |
- Christiansen, Ditte Marie, 1990-, et al.
(författare)
-
Effects of past and present microclimates on northern and southern plant species in a managed forest landscape
- 2023
-
Ingår i: Journal of Vegetation Science. - 1100-9233 .- 1654-1103. ; 34:4
-
Tidskriftsartikel (refereegranskat)abstract
- Questions: Near-ground temperatures can vary substantially over relatively short distances, enabling species with different temperature preferences and geographical distributions to co-exist within a small area. In a forest landscape, the near-ground temperatures may change due to management activities that alter forest density. As a result of such management activities, current species distributions and performances might not only be affected by current microclimates, but also by past conditions due to time-lagged responses.Location: Sweden.Methods: We examined the effects of past and current microclimates on the distributions and performances of two northern, cold-favoured, and two southern, warm-favoured, plant species in 53 managed forest sites. Each pair was represented by one vascular plant and one bryophyte species. We used temperature logger data and predictions from microclimate models based on changes in basal area to relate patterns of occurrence, abundance, and reproduction to current and past microclimate.Results: The two northern species were generally favoured by microclimates that were currently cold, characterised by later snowmelt and low accumulated heat over the growing season. In contrast, the two southern species were generally favoured by currently warm microclimates, characterised by high accumulated heat over the growing season. Species generally had higher abundance in sites with a preferred microclimate both in the past and present, and lower abundance than expected from current conditions, if the past microclimate had changed from warm to cold or vice versa, indicating time-lags in abundance patterns of the species.Conclusions: Our results show a potential importance of past and present microclimate heterogeneity for the co-existence of species with different temperature preferences in the same landscape and highlight the possibility to manage microclimates to mitigate climate change impacts on forest biodiversity.
|
|
| 3. |
- Christiansen, Ditte M., 1990-, et al.
(författare)
-
High-resolution data are necessary to understand the effects of climate on plant population dynamics of a forest herb
- 2024
-
Ingår i: Ecology. - 0012-9658 .- 1939-9170. ; 105:1
-
Tidskriftsartikel (refereegranskat)abstract
- Climate is assumed to strongly influence species distribution and abundance. Although the performance of many organisms is influenced by the climate in their immediate proximity, the climate data used to model their distributions often have a coarse spatial resolution. This is problematic because the local climate experienced by individuals might deviate substantially from the regional average. This problem is likely to be particularly important for sessile organisms like plants and in environments where small-scale variation in climate is large. To quantify the effect of local temperature on vital rates and population growth rates, we used temperature values measured at the local scale (in situ logger measures) and integral projection models with demographic data from 37 populations of the forest herb Lathyrus vernus across a wide latitudinal gradient in Sweden. To assess how the spatial resolution of temperature data influences assessments of climate effects, we compared effects from models using local data with models using regionally aggregated temperature data at several spatial resolutions (≥1 km). Using local temperature data, we found that spring frost reduced the asymptotic population growth rate in the first of two annual transitions and influenced survival in both transitions. Only one of the four regional estimates showed a similar negative effect of spring frost on population growth rate. Our results for a perennial forest herb show that analyses using regionally aggregated data often fail to identify the effects of climate on population dynamics. This emphasizes the importance of using organism-relevant estimates of climate when examining effects on individual performance and population dynamics, as well as when modeling species distributions. For sessile organisms that experience the environment over small spatial scales, this will require climate data at high spatial resolutions.
|
|
| 4. |
- Getachew, Merkebu, et al.
(författare)
-
Effects of shade tree species on soil biogeochemistry and coffee bean quality in plantation coffee
- 2023
-
Ingår i: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 347
-
Tidskriftsartikel (refereegranskat)abstract
- Shade trees are used in many coffee production systems across the globe. Beyond the benefits on biodiversity conservation, climate buffering, carbon sequestration and pathogen regulation, shade trees can impact the soil nutrient status via, for instance, litter inputs and nitrogen fixation. Since soil nutrients affect coffee quality and taste, there is also a potential indirect effect of shade tree species on coffee quality. Yet, in spite of the potentially large impact of shade tree species, quantitative data on the effects of shade trees on (i) soil biogeochemistry and (ii) the associated coffee bean quality remain scarce. To what extent four widely used shade trees species (Acacia abyssinica L., Albizia gummifera L., Cordia africana L. and Croton macrostachyus L.) in a plantation coffee agroforestry system impact soil biogeochemistry, and how this in turn affects coffee quality, measured as cupping scores and bean size. A significant negative impact of N-fixing shade tree species on soil pH and base cation concentrations was found. Plant-available and total phosphorus was enhanced by the presence of Albizia gummifera L. Thus, the present findings demonstrate that careful selection and integration of shade tree species such as Acacia abyssinica L. and Albizia gummifera L. into coffee production systems is a good practice for sustaining soil chemical properties in coffee agroecosystem. Despite the impacts on soil chemical characteristics, the shade tree species had no effect on coffee cup quality but did affect the bean mass. In this particular study, an attempt was made to quantify the impacts of widely used shade tree species on soil biogeochemistry and the subsequent effect on coffee bean quality in a plantation agroforestry system over the course of one season in southwest Ethiopia. However, it might be feasible to accommodate both relatively sparse time-series experimental data consisting of coffee farms from plantations and smallholders, which needs to be the goal of future research to accurately examine the impacts on the outcome variables.
|
|
| 5. |
- Hylander, Kristoffer, 1970-
(författare)
-
Living on the edge : effectiveness of buffer strips in protecting biodiversity on boreal riparian forests
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objective of this thesis is to evaluate the ecological consequences of buffer strip retention on riparian and terrestrial biodiversity. Earlier studies on forest buffer strips have evaluated their effectiveness in relation to water quality and aquatic biota. However, forests along streams are species rich habitats for many organism groups. Buffer strip management is assumed to be important also for protecting such species. Current approaches to biodiversity-oriented forest management practices need to be scientifically evaluated. In this thesis the effects on bryophytes and land snails have been evaluated.A before-and-after experiment along 15 small streams in northern Sweden showed that buffer strips of 10 m on each side of the stream moderated the negative effects exhibited at the clear-cuts. The number of land snail species remained similar as to before logging and the number of vanished bryophyte species was lower in the buffer strips than in the clear-cuts. The ground moisture influenced the survival rate of land snails at the clear-cuts. At mesic sites many species vanished but at wet sites the snail fauna was unaffected by the logging.Many bryophyte species, most of them liverworts, decreased or disappeared in the buffer strips. These were mostly growing on substrates elevated from the forest floor, such as logs, stumps and tree-bases. A number of nationally red-listed species, sensitive for changes in microclimate, were among those decreasing most. Thus, for the species in most need of protection the buffer strips were too narrow.An experiment with bryophyte transplants followed over a season showed that wet ground moisture moderated the negative edge effects in narrow buffer strips. On the other hand, the growth in mesic and moist sites was almost as low as in comparable clear-cuts.Microclimatic edge effects are stronger at south facing than north-facing edges of forest clear-cuts. This was shown in an experiment using bryophyte growth as an indicator of differences in microclimate. However, the depth of edge influence seemed to be similar between north- and south-facing forest edges, >30 m for one species. An explanation for this could be that wind penetrates deeper into edges than solar radiation and has a more variable direction.In conclusion, narrow buffer strips consist entirely of edge habitat. For many species the environment in buffer strips is good enough for persistence. For others, most notably bryophyte species on convex substrates, wider buffer strips are needed to ensure long-term survival.
|
|
| 6. |
- Kemppinen, Julia, et al.
(författare)
-
Microclimate, an important part of ecology and biogeography
- 2024
-
Ingår i: Global Ecology and Biogeography. - 1466-822X .- 1466-8238.
-
Tidskriftsartikel (refereegranskat)abstract
- Brief introduction: What are microclimates and why are they important? Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next.Microclimate investigations in ecology and biogeography: We highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles.Microclimate applications in ecosystem management: Microclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity.Methods for microclimate science: We showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state-of-the-art of the field.What's next? We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management.
|
|
| 7. |
- Kemppinen, Julia, et al.
(författare)
-
Microclimate, an important part of ecology and biogeography
- 2024
-
Ingår i: GLOBAL ECOLOGY AND BIOGEOGRAPHY. - 1466-822X .- 1466-8238. ; 33:6
-
Tidskriftsartikel (refereegranskat)abstract
- Brief introduction: What are microclimates and why are they important?Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next.Microclimate investigations in ecology and biogeographyWe highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles.Microclimate applications in ecosystem managementMicroclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity.Methods for microclimate scienceWe showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state-of-the-art of the field.What's next?We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management.
|
|
| 8. |
- Nurihun, Biruk Ayalew, 1983-, et al.
(författare)
-
Impact of climate and management on coffee berry disease and yield in coffee's native range
- 2024
-
Ingår i: Basic and Applied Ecology. - 1439-1791 .- 1618-0089. ; 76, s. 25-34
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change might increase plant diseases, reduce crop yields and threaten the livelihoods of millions of smallholder farmers globally. It is thus important to understand the relationships between climate, disease levels and yield to improve management strategies for sustainable agroforestry in a changing climate. One of the major threats to coffee production in Africa is the coffee berry disease (Colletotrichum kahawae). To investigate the effects of climatic and management variables on coffee berry disease (CBD) incidence and yield, we recorded minimum and maximum temperature and relative humidity, as well as CBD and yield, along a broad environmental and management gradient in southwestern Ethiopia during two consecutive years. CBD was affected by several climatic and management variables. For example, CBD incidence increased with minimum temperature during the fruit expansion stage, and decreased with minimum temperature during the endosperm filling stage. CBD incidence was negatively affected by the proportion of resistant cultivars, whereas the coffee structure index (pruning) had no effect on disease incidence. Coffee yield decreased with increasing minimum temperature during the flowering period in 2018 and maximum temperature during the fruit developmental period in 2019. Coffee yield was negatively affected by canopy cover and positively affected by the coffee structure index in both years. Our findings highlight that CBD and yield were affected by different climatic and management variables. Yet, managing for low disease levels and high yield is practically difficult due to season -dependent effects of several climatic variables. One way to break the correlation of climatic variables between seasons might be to take advantage of differences among shade trees in the presence or timing of leaf drop. To reduce CBD incidence, using resistant cultivars is an effective strategy, but this might threaten the wild coffee genetic reservoir.
|
|
| 9. |
- Nurihun, Biruk Ayalew, 1983-, et al.
(författare)
-
Impact of climate on a host-hyperparasite interaction on Arabica coffee in its native range
- 2024
-
Ingår i: Journal of Applied Ecology. - 0021-8901 .- 1365-2664. ; 61:3, s. 538-550
-
Tidskriftsartikel (refereegranskat)abstract
- Natural enemies of plant pathogens might play an important role in controlling plant disease levels in natural and agricultural systems. Yet, plant pathogen–natural enemy interactions might be sensitive to climatic changes. Understanding the relationship between climate, plant pathogens and their natural enemies is thus important for developing climate-resilient, sustainable agriculture.To this aim, we recorded shade cover, daily minimum and maximum temperature, relative humidity, coffee leaf rust and its hyperparasite at 58 sites in southwestern Ethiopia during the dry and wet season for 2 years.Coffee leaf rust severity was positively related to the maximum temperature. Hyperparasite severity was higher when the minimum temperature was low (i.e. in places with cold night temperatures). While canopy cover did not have a direct effect on rust severity, it reduced rust severity indirectly by lowering the maximum temperature. Canopy cover had a direct positive effect on the hyperparasite severity during one surveying period.Synthesis and applications. Our findings highlight that coffee leaf rust and its hyperparasite are both affected by shade cover and temperature, but in different ways. On the one hand, these niche differences lead to the worrying prediction that levels of coffee leaf rust will increase, and its hyperparasite will decrease, with climate change. On the other hand, these niche differences between coffee leaf rust and its hyperparasite provide opportunities to develop strategies to manage the environment (such as shade cover and microclimate) in such a way that the rust is disfavoured and the hyperparasite is favoured.
|
|
| 10. |
- Nurihun, Biruk Ayalew, 1983-, et al.
(författare)
-
Using local knowledge to reconstruct climate-mediated changes in disease dynamics and yield-A case study on Arabica coffee in its native range
- 2024
-
Ingår i: Plants, People, Planet. - 2572-2611.
-
Tidskriftsartikel (refereegranskat)abstract
- Societal Impact StatementAdapting agriculture to climate change requires an understanding of the long-term relationship between climate, disease dynamics, and yield. While some countries have monitored major crop diseases for decades or centuries, comparable data is scarce or non-existent for many countries that are most vulnerable to climate change. For this, a novel approach was developed to reconstruct climate-mediated changes in disease dynamics and yield. Here, a case study on Arabica coffee in its area of origin demonstrates how to combine local knowledge, climate data, and spatial field surveys to reconstruct disease and yield time series and to postulate and test hypotheses for climate-disease-yield relationships.Summary While some countries have monitored crop diseases for several decades or centuries, other countries have very limited historical time series. In such areas, we lack data on long-term patterns and drivers of disease dynamics, which is important for developing climate-resilient disease management strategies.We adopted a novel approach, combining local knowledge, climate data, and spatial field surveys to understand long-term climate-mediated changes in disease dynamics in coffee agroforestry systems. For this, we worked with 58 smallholder farmers in southwestern Ethiopia, the area of origin of Arabica coffee.The majority of farmers perceived an increase in coffee leaf rust and a decrease in coffee berry disease, whereas perceptions of changes in coffee wilt disease and Armillaria root rot were highly variable among farmers. Climate data supported farmers' understanding of the climatic drivers (increased temperature, less rainy days) of these changes. Temporal disease-climate relationships were matched by spatial disease-climate relationships, as expected with space-for-time substitution.Understanding long-term disease dynamics and yield is crucial to adapt disease management to climate change. Our study demonstrates how to combine local knowledge, climate data and spatial field surveys to reconstruct disease time series and postulate hypotheses for disease-climate relationships in areas where few long-term time series exist.
|
|
