Mapping <i>Prosopis </i>spp. within the Tarach water basin, Turkana, Kenya using Sentinel-2 imagery

Ng, Wai‐Tim; Immitzer, Markus; Floriansitz, Matthias; Vuolo, Francesco; Luminari, L.; Adede, Chrisgone; Wahome, R.G.; Atzberger, Clement

doi:10.1117/12.2241279

Cited by 6 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To model the Eastern African niches, we used data collected during several ground surveys between 2008 and 2017 (Ng et al. , , Shackleton et al. , Witt et al.…”

Section: Methodsmentioning

confidence: 99%

Niche change analysis as a tool to inform management of two invasive species in Eastern Africa

et al. 2020

View full text Add to dashboard Cite

Significant progress has been made in providing guidelines and recommendations for assessing the ecological niche, stage of invasion, and probability of invasive alien plant species (IAPS) potential distribution in space and time. We followed these recommendations by developing and comparing ordination and species distribution models (SDMs) of two important woody IAPS in Eastern Africa, Prosopis juliflora and Lantana camara, and interpreting the results to inform IAPS management. The two species differ in their invasion history in Eastern Africa; while L. camara was widely introduced there in the 19th century, P. juliflora was only planted at selected locations in the 1970s and 1980s. For the SDMs, machine learning algorithms were used to generate one ensemble model each for P. juliflora and L. camara. For ordination, we used bioclimatic variables, performed a principal component analysis, and compared the native and global niches of the species with the Eastern African niche. Niches varied substantially depending on the percentage of marginal climates excluded from the models. Additional analysis of the local niches surrounding the original P. juliflora plantations showed that they are complementary, which may have led to an overestimation of regional niche filling. While niche expansion was absent or small depending on the percentage of marginal climates excluded, analysis of the stages of invasion suggested that P. juliflora may have started to adapt to novel climatic conditions and that L. camara is approaching a pseudo‐stable equilibrium in Eastern Africa. The SDMs showed that large areas in Eastern Africa that have not yet been invaded by P. juliflora are suitable or will become suitable with climate change. For L. camara, the global SDM predicted a considerably larger suitable area than the Eastern African one, raising uncertainty about the areas to be included in a regional management strategy. Thus, combining ordination and SDMs and integrating a geographic component into ordination is useful in assessing IAPS invasion stages and potential niche shifts, and the results help inform IAPS policy and management. The combined approach can also serve to guide experimental studies addressing divergences between results generated with the different approaches.

show abstract

“…To model the Eastern African niches, we used data collected during several ground surveys between 2008 and 2017 (Ng et al. , , Shackleton et al. , Witt et al.…”

Section: Methodsmentioning

confidence: 99%

Niche change analysis as a tool to inform management of two invasive species in Eastern Africa

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The Turkana County in Kenya was selected as study area because of the high prevalence of Prosopis spp . (Ng, Immitzer, et al, ). The study area is located in the Rift Valley of northern Kenya (Figure ) between latitudes 01°00′N and 05°28′N and longitude 34°02′E and 36°43′E, covering 68,680 km 2 .…”

Section: Methodsmentioning

confidence: 99%

“…The Turkana County in Kenya was selected as study area because of the high prevalence of Prosopis spp. (Ng, Immitzer, et al, 2016a). The…”

Section: Study Areamentioning

confidence: 99%

“…The EM output was in agreement with our field observations and in correspondence with the Prosopis spp. cover for the Tarach basin, Turkana County, Kenya mapped in 2016 (Ng, Immitzer, et al, 2016a). This study applied remote sensing for detecting the Prosopis spp., cover in 2016, using Sentinel-2 satellite data and in situ observations.…”

Section: Potential Distribution and Invasion Patternmentioning

confidence: 99%

“…In Turkana County, Kenya Prosopis spp. has become omnipresent (Ng, Immitzer, et al, 2016a). It is crucial to understand its invasion dynamics to effectively negate the adverse impacts and to build analytical frameworks to manage priority areas, that is, early detection of outbreaks and eradication efforts (Schachtschneider & February, 2013;Shackleton, Maitre, Pasiecznik, & Richardson, 2014).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ensemble approach for potential habitat mapping of invasive Prosopis spp. in Turkana, Kenya

Silva

Rima

et al. 2018

Ecology and Evolution

Self Cite

View full text Add to dashboard Cite

Aim Prosopis spp. are an invasive alien plant species native to the Americas and well adapted to thrive in arid environments. In Kenya, several remote‐sensing studies conclude that the genus is well established throughout the country and is rapidly invading new areas. This research aims to model the potential habitat of Prosopis spp. by using an ensemble model consisting of four species distribution models. Furthermore, environmental and expert knowledge‐based variables are assessed.LocationTurkana County, Kenya.MethodsWe collected and assessed a large number of environmental and expert knowledge‐based variables through variable correlation, collinearity, and bias tests. The variables were used for an ensemble model consisting of four species distribution models: (a) logistic regression, (b) maximum entropy, (c) random forest, and (d) Bayesian networks. The models were evaluated through a block cross‐validation providing statistical measures.ResultsThe best predictors for Prosopis spp. habitat are distance from water and built‐up areas, soil type, elevation, lithology, and temperature seasonality. All species distribution models achieved high accuracies while the ensemble model achieved the highest scores. Highly and moderately suitable Prosopis spp. habitat covers 6% and 9% of the study area, respectively.Main conclusionsBoth ensemble and individual models predict a high risk of continued invasion, confirming local observations and conceptions. Findings are valuable to stakeholders for managing invaded area, protecting areas at risk, and to raise awareness.

show abstract

Integrated Participatory Approach Reveals Perceived Local Availability of Wild Edible Plants in Northwestern Kenya

et al. 2022

View full text Add to dashboard Cite

Availability is a crucial aspect of wild edible plants (WEPs) consumption by indigenous communities. Understanding the local perception of this availability helps to determine, which contribution WEPs can make to rural communities. We used an integrated participatory approach to investigate important parameters and themes that influenced the perception of availability of woody WEPs. We demonstrate the approach in three communities in Turkana County, Kenya. By availability, we referred to the ease of accessing, harvesting, transporting, and processing WEPs for consumption. We conducted three focus group discussions (FGDs). We asked FGD participants to list, score, and discuss availability. We used logistic regression and mixed-content analysis to identify important parameters and themes, respectively. The most important WEPs were the toothbrush tree (Salvadora persica L.), Indian jujube (Ziziphus mauritiana Lam.), and mbamba ngoma (Balanites rotundifolia (Tiegh.) Blatt.). Distance, seasonality, price, and adequacy of harvested WEPs for household consumption were important parameters. Culture and tradition, distribution of WEPs, seasonality, and climate change emerged as important themes. We showed the importance of using an integrated participatory approach when assessing the perception of WEPs’ availability by local communities and could be used in comparable arid and semi-arid areas with semi-nomadic pastoralists across Africa.

show abstract

Mapping Prosopis spp. within the Tarach water basin, Turkana, Kenya using Sentinel-2 imagery

Cited by 6 publications

References 18 publications

Niche change analysis as a tool to inform management of two invasive species in Eastern Africa

Niche change analysis as a tool to inform management of two invasive species in Eastern Africa

Ensemble approach for potential habitat mapping of invasive Prosopis spp. in Turkana, Kenya

Integrated Participatory Approach Reveals Perceived Local Availability of Wild Edible Plants in Northwestern Kenya

Contact Info

Product

Resources

About