Airborne remote sensing of spatiotemporal change (1955–2004) in indigenous and exotic forest cover in the Taita Hills, Kenya

Pellikka, Petri; Lötjönen, Milla; Siljander, Mika; Lens, Luc

doi:10.1016/j.jag.2009.02.002

Cited by 155 publications

(196 citation statements)

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“…Kasigau ( À3 182 0 N; 38 165 0 E; B1500 m) still harbour pristine, interconnected and intact cloud forest, in which 46 and 22 individuals were sampled, respectively; (ii) In the Chyulu Hills ( À2 166 0 N; 37 187 0 E; B2200 m), cloud forests constitute a forest-grassland mosaic that has at least persisted since the Massai pastoralists caused regular fires many hundreds of years ago. A total of 52 individuals were sampled in two forest fragments located at the northern-and southernmost edges of the mountain range; (iii) In the Taita Hills ( À3 141 0 N; 38 130 0 E; B1800 m), continuous cloud forest has been transformed into isolated and degraded forest remnants mainly due to small-scale subsistence agriculture, with a particularly marked loss, deterioration and isolation of the remaining forest cover since the 1960s (Pellikka et al, 2009). Here, a total of 270 individuals were sampled in 11 forest fragments located along the entire higher elevational range.…”

Section: Sampling Schemementioning

confidence: 99%

“…We sampled populations in each of the above mentioned forest types with contrasting habitat history and current characteristics. To study genetic and phenotypic population effects of rapid habitat change, we sampled and measured both museum specimens and current captures, covering past and recent episodes of forest fragmentation (Pellikka et al, 2009). We further performed Species Distribution Models (SDMs) based on bioclimatic variables to project current and future (2080) climatic niches of Z. poliogaster.…”

Section: Introductionmentioning

confidence: 99%

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Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

Habel

Mulwa

Gassert³

et al. 2014

Heredity

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The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size.

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Section: Sampling Schemementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

Habel

Mulwa

Gassert³

et al. 2014

Heredity

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“…In particular, several studies indicate that space-borne sensors can be used to obtain spatially extensive information from landscapes on a global scale (Hu et al, 2007;Lamonaca et al, 2008;Pellikka et al, 2009;Propastin and Panferov, 2013).…”

Section: Fvc (Fractional Vegetationmentioning

confidence: 99%

Estimation of Fractional Vegetation Cover in Sand Dunes Using Multi-spectral Images from Fixed-wing UAV

Choi¹,

Lee²,

Jung³

et al. 2016

Journal of the Korean Society of Surveying, Geodesy, Photogramm

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Since the use of UAV (Unmanned Aerial Vehicle) is convenient for the acquisition of data on broad or inaccessible regions, it is nowadays used to establish spatial information for various fields, such as the environment, ecosystem, forest, or for military purposes. In this study, the process of estimating FVC (Fractional Vegetation Cover), based on multi-spectral UAV, to overcome the limitations of conventional methods is suggested. Hence, we propose that the FVC map is generated by using multi-spectral imaging. First, two types of result classifications were obtained based on RF (Random Forest) using RGB images and NDVI (Normalized Difference Vegetation Index) with RGB images. Then, the result map was reclassified into vegetation and nonvegetation. Finally, an FVC map-based RF were generated by using pixel calculation and FVC map-based GI (Gutman and Ignatov) model were indirectly made by fixed parameters. The method of adding NDVI shows a relatively higher accuracy compared to that of adding only RGB, and in particular, the GI model shows a lower RMSE (Root Mean Square Error) with 0.182 than RF. In this regard, the availability of the GI model which uses only the values of NDVI is higher than that of RF whose accuracy varies according to the results of classification. Our results showed that the GI mode ensures the quality of the FVC if the NDVI maintained at a uniform level. This can be easily achieved by using a UAV, which can provide vegetation data to improve the estimation of FVC. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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“…In this study, we focus on the Taita Hills, in south-eastern Kenya, where the overuse of natural resources and consequent environmental degradation (e.g. Newmark 1998;Pellikka et al 2009;Erdogan et al 2011) are placing pressure on water-related ES. We use historical analysis to trace the changes undergone by water-related ES during the last few decades and assess the factors that have created a situation of unsustainable management (Mosse 1997;Adger et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Local assessment of changes in water-related ecosystem services and their management: DPASER conceptual model and its application in Taita Hills, Kenya

Hohenthal

Owidi

Minoia

et al. 2015

International Journal of Biodiversity Science, Ecosystem Servic

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Fresh water provisioning is a crucial ecosystem service (ES) in the agrarian societies of East Africa. Water resources are highly dependent on several other ES such as the water retention capacity of vegetation and the purification properties of soil. However, ES are constantly challenged by dynamic changes within water-land-vegetation-human relations. Environmental policies usually address immediate anthropic pressures but overlook multiple historical stressors, or 'drivers'. This article presents a local assessment of changes in the water-related ES in the Taita Hills, Kenya, applying the Drivers, Pressures, Actions, State, Ecosystem services, Responses (DPASER) model, adapted from the Drivers, Pressures, State, Impacts, Responses (DPSIR) framework, boosted with ecosystem services and human actions and combined into a historical perspective. A review of the legislation, interviews, participatory mapping, timelines and focus group discussions were used in data gathering. The results indicate that land demarcation in the 1960s and consequent land privatization have been the main drivers of change in water-related ES, since these determined the prioritization of agricultural production over conservation of forests, wetlands and rivers. This case study shows that the degradation of water-related ES is strongly linked to historical development of land ownership and loss of commonality, and suggests enhancement of inter-sectoral management.

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Airborne remote sensing of spatiotemporal change (1955–2004) in indigenous and exotic forest cover in the Taita Hills, Kenya

Cited by 155 publications

References 19 publications

Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

Estimation of Fractional Vegetation Cover in Sand Dunes Using Multi-spectral Images from Fixed-wing UAV

Local assessment of changes in water-related ecosystem services and their management: DPASER conceptual model and its application in Taita Hills, Kenya

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