Invasive Futures

Traditional rangeland management systems and livelihoods in Kenya generally, and in the Baringo basin specifically, are slowly changing due to environmental and ecological pressures and system-immanent drivers such as rangeland degradation and changing aspirations of the land users. Invasive plant species are spreading rapidly and taking over the pastoral communal lands, hindering livestock mobility. Households are transitioning to crop agriculture to adapt to the invasion, but as arable farming expands, the seasonal availability and quality of pasture decreases, further negatively impacting agro-pastoral livelihoods. Ecological shocks such as plant invasion thus become a key element in future-making, as they will accelerate social-ecological transitions and livelihood transformative processes in future rangelands.

• Which resource attributes and management practices favour enhanced invasion of alien plant species?

• How does invasion affect the productivity of crop- and rangelands (e.g., forage availability and quality, crop yields) and shape future systems shifts?

• Which economic constraints, risks, and opportunities affect aspirations, and how do aspirations affect systems dynamics, including agrarian and livelihood changes, and future-related behaviour (economic mobility)?

• Which feedback processes and patterns of transformation from agrarian and livelihood changes emerge, and how do poverty and aspiration traps constitute barriers to future-making capacities? How do patterns differ across diverse agents (by gender, class, ethnicity, and other intersectional factors?

• What is the potential of role models and collective action on invasion management?

• Analysis of digital elevation models
• Monitoring of wells
• Remote sensing soil moisture assessments
• Geostatistical modelling
• Isotopic analysis of topsoil organic matter
• Mass-spectrometric analysis of stable isotopes
• Diachronic analysis
• Analysis of fast-moving ecological threats (locusts and fall armyworm)
• Individual, household, and field surveys
• Focus group discussions
• Behavioural-economic experiments

a) Invasive spread: Prosopis has been established in the area since the 1980s. It is mostly found in the seasonally inundated plains, where 65% of households report being infested. Grazed pastures had much higher infestations than frequently cropped farmlands, and semi-nomadic pastoralists and agro-pastoralist households were more impacted by Prosopis infestation than cropland farmers.

Parthenium was reported by most pastoralists and many crop farmers to be an emergent problem in the area. It invades mainly moist places, along irrigation and drainage channels, and as ruderal plant along roadsides (water runoff from tarmac roads create moist niche environments). Parthenium is likely to expand north of Marigat supporting progressing infrastructure development and system shift from (agro-)pastoralism towards sedentary crop cultivation.

b) Environmental attributes: Results indicate that high stand densities or recent spread dynamics of Parthenium and Prosopis are closely linked with high soil moisture or with larger quantities of available water in the environment. Thus, seasonal dynamics of soil moisture are related to dynamics in seed germination, growth, and stand densities of the invasive plants. The relation between species vigor and recent spread dynamics appears further to be associated with soil fertility attributes such as relatively high soil C and N contents, with low C:N ratios in the soil organic matter, and, to a lesser extent, with plant available P.

c) Impact on households and livelihoods: An economic survey collected attributes of 530 households and aspirations of farmers and (agro-)pastoralists in the face of these invasive species and the related livelihood threats. Households generally aspire beyond their current status regarding income, assets, livestock, and social status. However, ecological shocks such as massive invasion dynamics of Prosopis and the emerging spread of Parthenium have negative effects on aspirations. Education, access to agricultural extension services, and households’ wealth status are additional determinants of aspiration formation. Cooperative membership contributes positively to the formation of income and asset aspirations.

d) Response strategies and land-use patterns: Coping with risks and uncertainties entails changes in livelihood strategies and shifts in production systems. Preliminary observations indicate that practices of future-making appear to be dominated by shifts from pastoral land use towards agro-pastoralism or even intensive crop farming. However, the extent of livelihood shifts further appears to depend on resource endowments and physical, social, and educational infrastructure, with better-off actors acting as pacemakers. Men-headed households are observed to engage more and sustain their engagement in diversified livelihoods, specifically intensive crop farming and agro-pastoralism with larger livestock, while a substantial number of women-headed households (mainly widows) remain in single livelihoods, such as small-scale livestock raising. The differences in aspirations, with women having lower aspirations, are associated with these different livelihood transitions. While women may aspire to shift to invasion-adaptive livelihood strategies, they are unable to translate their aspirations into actions due to their poor endowments.

The integrated agro-economic project on invasive futures is linked to several CRC projects – such as “Future roads” (B05) which will together study the effects of progressing infrastructure developments around Lake Baringo on the spread dynamics of invasive plants and the effects of invasive spread dynamics as push - pull factors for system shift. A GIS-based analysis of soil-moisture maps and road constructions will provide input to the model for explaining current and projecting future invasive-species distribution. Together with project on “Future Infections” (B02) the project will use the invasive-spread mapping to target studies on vector populations for of arboviral spread and the emerging risks. Invasion-related arboviral infections may constitute an additional push force that can accelerate land-use changes.

Publications:

• Bacud, Heckelei, Ihli. The unknown link between aspiration and livelihoods: Does aspiration explain gendered livelihood diversification in pastoral settings?
• Ihli, Heckelei, Rommel, Baylis. Impact of collective action video intervention on farmers' community aspirations and cooperation in invasive species management: Evidence from an RCT in Kenya
• Mutuku, Becker, Kamiri. The role of parthenium invasion on agricultural land use change in the Njemp Flats: A change detection analysis.

Master's Theses:

• The trajectories of rural livelihoods and welfare outcomes in agro-pastoral zones in four African countries: Are farmers’ livelihood dynamics a transformation or survival process?
• Gendered perceptions of ecological degradation and preferences in control management
• Gendered impacts of invasive plant land invasion on aspirations
• Contract farming and land use dynamics – How does contract farming impact livelihood/land use dynamics of agro-pastoralists
• Aspirations and agricultural technological investments in rural Africa
• Parthenium invasion dynamics on performance attributes of selected field crops and pastures.
• Soil attributes and Parthenium invasion dynamics- How do soil fertility attributes and soil moisture patterns influence Parthenium invasion dynamics?