Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Kürdistan’inda Kontrgerilla Stratejisi Olarak Çevre Tahribati
    Etten, J. van; Jongerden, J.P. ; Vos, H. de; Klaasse, A. ; Hoeve, A. - \ 2009
    Toplum ve Kuram 1 (2009)1. - p. 71 - 95.
    This study examines environmental aspects of the conflict between the Turkish state and the insurgent Kurdistan Workers Party (Partiya Karkerên Kurdistan or PKK). Since the early 1990s, several civil society groups have claimed that the Turkish army burned forests and destroyed other livelihood resources in the Kurdistan region of Turkey as it evacuated settlements. This study reports the results of a case study of destruction in Tunceli, eastern Turkey, undertaken in order to evaluate support for such claims. The geospatial techniques in case-specific approaches to the study of armed conflict had been used for this purpose. Through the analysis of satellite images, this study verified eyewitness reports and confirmed that substantial burnings did indeed take place in the study area between 1991 and 1994. It is argued that this destruction was not irrational or wan-ton, but that it was part of a strategy used by the Turkish army in the early 1990s that aimed at actively transforming the war environment
    Images of war: using satellite images for human rights monitoring in Turkish Kurdistan
    Vos, H. de; Jongerden, J.P. ; Etten, J. van - \ 2008
    Disasters 32 (2008)3. - ISSN 0361-3666 - p. 449 - 466.
    In areas of war and armed conflict it is difficult to get trustworthy and coherent information. Civil society and human rights groups often face problems of dealing with fragmented witness reports, disinformation of war propaganda, and difficult direct access to these areas. Turkish Kurdistan was used as a case study of armed conflict to evaluate the potential use of satellite images for verification of witness reports collected by human rights groups. The Turkish army was reported to be burning forests, fields and villages as a strategy in the conflict against guerrilla uprising. This paper concludes that satellite images are useful to validate witness reports of forest fires. Even though the use of this technology for human rights groups will depend on some feasibility factors such as prices, access and expertise, the images proved to be key for analysis of spatial aspects of conflict and valuable for reconstructing a more trustworthy picture
    Environmental destruction as a counterinsurgency strategy in the Kurdistan region of Turkey
    Etten, J. van; Vos, H. de; Jongerden, J.P. ; Klaasse, A. ; Hoeve, E. van - \ 2008
    Geoforum 39 (2008)5. - ISSN 0016-7185 - p. 1786 - 1797.
    armed conflict - civil-war - science - scale
    We examine environmental aspects of the conflict between the Turkish state and the insurgent Kurdistan Workers Party (Partiya Karkerên Kurdistan or PKK). Since the early 1990s, several civil society groups have claimed that the Turkish army burned forests and destroyed other livelihood resources in the Kurdistan region of Turkey as it evacuated settlements. We report the results of a case study of destruction in Tunceli, eastern Turkey, undertaken in order to evaluate support for such claims. We demonstrate the use of geospatial techniques in case-specific approaches to the study of armed conflict. Through the analysis of satellite images, we verified eyewitness reports and confirmed that substantial burnings did indeed take place in the study area between 1991 and 1994. We argue that this destruction was not irrational or wanton, but that it was part of a strategy used by the Turkish army in the early 1990s that aimed at actively transforming the war environment
    Genetic diversity of maize (Zea mays L. ssp. mays) in communities of the western highlands of Guatemala: geographical patterns and processes.
    Etten, J. van; Fuentes, M.R. ; Molina, L.G. ; Ponciano, K.M. - \ 2008
    Genetic Resources and Crop Evolution 55 (2008)2. - ISSN 0925-9864 - p. 303 - 317.
    natural-populations - similarity - markers - mexico - flow
    This study concerns spatial genetic patterning, seed flow and the impact of modern varieties in maize populations in Chimaltenango, Guatemala. It uses a collection of 79 maize seed samples from farmers in the area and five samples derived from modern varieties. Bulked SSR markers employed with bulked samples (ten plants) were used. Genetic distances between populations based on these SSR data were used as a measure of co-ancestry. The study describes the genetic variation in space, assesses the association of maize diversity with spatial and environmental descriptors and quantitative traits, and provides a test of the impact of improved varieties. Maize diversity showed significant isolation-by-distance locally, but not regionally. This was interpreted as evidence for a difference between local and regional mechanisms of seed exchange; regional exchange is more related to innovation. There was also a significant association with altitude and ear/grain characteristics (related to racial classifications). Also, consistent evidence for the influence of modern varieties of maize was found, although its impact was limited spatially. It is argued that the spatial distributions of maize diversity are important to consider for germplasm collection, but should be seen as a recent outcome of dynamic processes.
    Forest Burning as Counter-Insurgency in Turkish Kurdistan: an analysis from space
    Jongerden, J.P. ; Vos, H. de; Etten, J. van - \ 2007
    International Journal of Kurdish Studies 21 (2007)1&2. - ISSN 1073-6697 - p. 1 - 15.
    Spatial-data sharing: Applying social-network analysis to study individual and collective behaviour
    Omran, E.S.E. ; Etten, J. van - \ 2007
    International Journal of Geographical Information Science 21 (2007)6. - ISSN 1365-8816 - p. 699 - 714.
    centrality
    Spatial-Data Sharing (SDS) is a crucial aspect of spatial-data infrastructures. This paper introduces Social-Network Analysis to research on SDS. By mapping out relationships among social actors using Social-Network Analysis, the collective properties of SDS in organizations can be investigated. Previous theoretical approaches have focused exclusively on individual behaviour. This paper attempts to expand this focus and applies Social-Network Analysis in a study of SDS in a project of the Egyptian Survey Authority. It concentrates on the emerging pattern of SDS between social actors in the organization and their perceptions and attitudes. Social-Network Analysis results show that SDS in this organization corresponds strongly to the existing hierarchy in the organization. Individual beliefs and perceptions of SDS show patterns that correspond strongly to the network structure. Project leaders are central in the SDS network and optimistic about SDS. Workers lower in the organization feel they have less control and express more concern about constraints regarding SDS than workers higher up in the organization. The paper shows that Social-Network Analysis can be a useful tool to study SDS and complements approaches to individual behaviour. Social-Network Analysis could be expanded to study inter-organizational SDS, could be implemented with digital technology, and could be refined to distinguish behaviour and networks according to different information types.
    Regional and local maize seed exchange and replacement in the western highlands of Guatemala
    Etten, J. van; Bruin, S. de - \ 2007
    Plant genetic resources: characterization and utilization 5 (2007)2. - ISSN 1479-2621 - p. 57 - 70.
    Regional distributions of crop diversity are important to take into account for the spatial design of in situ, farmer-participatory interventions in crop genetic management. Regional seed flows are an important factor in shaping geographical distributions of crop diversity. This study contributes to the insight in these seed flows, focusing on maize (Zea mays L.) in Chimaltenango, an area in the western highlands of Guatemala. A social survey of 257 households on different aspects of seed management produced information on cultivar naming, seed sources, reasons and causes of the discontinuation of seed lots, and important explanatory variables associated with different seed sources. A small portion of the reported seed lots originated from regional seed sources. The main motivation of regional seed exchange and the discontinuation of seed lots was to achieve change in plant characteristics of the crop, especially to obtain lower plants and shorter growing cycles. It is argued that farmer selection fails to achieve such change, and in fact leads to an equilibrium with high plants and long growing cycles. Seed exchange functions as an escape to this trend. Other factors of influence on seed exchange are altitude and ethnicity. The study also highlights the issue of geographical directionality in seed exchange patterns.
    Changes in farmers' knowledge of maize diversity in highland Guatemala
    Etten, J. van - \ 2006
    Journal of Ethnobiology and Ethnomedicine 2 (2006)12. - ISSN 1746-4269 - p. 1 - 17.
    Small-scale studies on long-term change in agricultural knowledge might uncover insights with broader, regional implications. This article evaluates change in farmer knowledge about crop genetic resources in highland Guatemala between 1927/37 and 2004. It concentrates on maize (Zea mays ssp. mays L.) in one Guatemalan township, Jacaltenango, an area with much ecological and maize diversity. It relies on a particular type of baseline information: lists of farmer-defined cultivars drawn up by ethnographers in the first half of the twentieth century. A questionnaire format based on two independent lists of local farmer cultivars dating from 1927 and 1937 was used to assess changes in maize diversity. Comparisons between attributes given to each cultivar in the past and in 2004 were used as a partial test of the stability of cultivar identity. In farmers' perceptions, cultivar loss was low and limited to certain cultivars adapted to the warmer environments. Crop production problems were mentioned as the main motives for change. No evidence for a loss of cultivars due to the political violence of the 1980s was found. In the lower areas many newly introduced cultivars were found, which reportedly provide solutions for the production problems the older cultivars have. The article contrasts these findings with those of an earlier study which suggested much cultivar loss due to political violence, and draws conclusions about the methodological implications
    Forest burning as a counterinsurgency strategy in Eastern Turkey. Paper presented at the World Congress of Kurdish Studies, organized by the Kurdish Institute of Paris and Salahaddin University, Arbil, Iraqi Kurdistan, September 6 to September 9, 2006
    Jongerden, J.P. ; Etten, J. van; Vos, H. de - \ 2006
    - 16 p.
    Beginning in the early 1990s, the Turkish Army was reported to use the burning of forests, fields and villages as a strategy in the conflict against the insurgent PKK. A case study of armed conflict in Tunceli, Eastern Turkey was done to evaluate this claim using satellite images for the verification of eye-witness reports collected by human rights groups. This paper establishes that substantial forest burnings took place between 1991 and 1994 in the study area. Turkey follows an international trend of resource destruction as an intentional goal of its counterinsurgency strategy
    Seeds, hands and lands : maize genetic resources of highland Guatemala in space and time
    Etten, J. van - \ 2006
    Wageningen University. Promotor(en): Paul Richards; Arnold Bregt, co-promotor(en): Sytze de Bruin; Harro Maat. - - 132
    boeren - kennis - maïs - plantenveredeling - genetische bronnen van plantensoorten - genetische diversiteit - bedrijfsvoering - innovaties - guatemala - zea mays - farmers - knowledge - maize - plant breeding - plant genetic resources - genetic diversity - management - innovations - guatemala - zea mays
    Crop genetic resources are an important aspect of agricultural production. Agricultural innovation through plant breeding is generally seen as an efficient means to support food security and economic development in poor areas. Modern varieties of maize, a major cereal and the subject of this study, are at present used on roughly half of the tropical acreage of this crop. Several strategies are being developed to reach the other half, which involve farmers being more active in the innovation process. Field studies of farmers' seed and crop management aim to support the design of farmer-participatory plant breeding activities. In these approaches and studies there is a tendency to focus on seed selection as the core process of plant genetic innovation. The present study concentrates on the gene pool of maize in the western highlands ofGuatemala, as shaped by seed exchange and replacement by farmers. Maize is traditional in this area, and the main food crop.

    Chapter 1 gives a conceptual critique of existing models in participatory plant breeding. There is a tendency to focus on seed selection as the core process of plant genetic innovation. The present study argues that this model should be broadened and sees gene flow as a part of the creative process of crop evolution. This conceptual change implies that more attention should be paid to seed exchange, as seeds are a main vehicle for gene flow in cereals. Also, attention should not be paid only to individual decision making but also to the connections and structures which provide the conditions under which exchange takes place. Over longer periods, individual seed exchange transactions add up to a collective gene pool structure, with 'emergent' properties beyond the scope of individual farmers, but nevertheless important for the design of management strategies for crop genetic resources. The goal of this research is to gain insight into the shaping of the gene pool as a collective entity in the case of highlandGuatemala. To reach this goal, this study combines different research methods in an interdisciplinary way to reconstruct historical change and explain the current geographical structure in the maize gene pool.

    Chapter 2 explores the historiographic and ethnographic literature on highlandGuatemalato sketch five centuries of change in social connectivity and technological needs and identifying disasters with consequences for maize seed. It suggests that events like human disease epidemics of the colonial period, resulting in demographic decline, have had an important influence on the continuity and spatial distribution of maize genetic resources. Also it is pointed out that the twentieth century brought both regional social integration and local fragmentation, and that this, together with demographic recuperation, is important in relation to the maize biodiversity and farmers' knowledge about it. Concerns about diversity conservation should not lead to attempts to resist economic integration; the formerly closed character of communities is largely a colonial product and historical connections between communities are perhaps deeper than often thought. The same may go for maize genetic resources. Instead, maize agriculture should confront the challenges of modernity in ways that support collaboration between communities.

    Chapter 3 elaborates a more detailed study on historical change in farmer knowledge about maize diversity between 1927/1937 and 2004. In 1927 and 1937, two lists with local cultivars and their characteristics were drawn up by ethnographers for thetownshipofJacaltenango. Close inspection made clear that these two lists were rather consistent, and that a useful comparison with data on farmer knowledge in 2004 could thus be made. By using a sample of informants spread across several communities and ecologies in the township, an unequal spatial distribution of farmer knowledge was anticipated. A technique from cognitive anthropology, consensus analysis, was used to assess the likelihood of consensus about the presence of each cultivar. The current study found that absolute diversity losses were few, and involved cultivars that are probably not genetically unique, since they were introduced before 1937 as a result of labour migration to coffee farms. Many newly introduced maize types were reported by farmers. Seed introductions corresponded to different forms of regional mobility, including forced migration and maize trade. This chapter further highlights the importance of taking into account spatial differences in knowledge between communities in the same township. A previous study in the same area, based on interviews in several township head towns, concluded, incorrectly, according to the present study, that substantial cultivar losses had occurred.

    Chapter 4 investigates contemporary farmer seed exchange and replacement based on 257 formal interviews in the highland townships of Chimaltenango. The study focuses on (1) the spatial distribution of cultivar names, (2) seed sources and flows, (3) reasons to discard seeds and (4) variables explaining choices between different seed sources. The fourth element was based on the application of classification trees to the interview data, supplemented with spatial data from another source. The distribution of cultivar names suggested that regional exchange of seeds of traditional and modern varieties occurs, but is constrained by altitudinal differences in the landscape. The data also indicate that most seed flows are local, and that regional seed flows are mostly taking place within the administrative department. Regional seed flows originate often in cities. When farmers discarded seed lots they were mainly motivated by their disadvantages (high plants and long growing cycles). This result was consistent with the finding that regional seed introductions were associated with seed lots with short plants and short growing seasons. This confirms that regional seed exchange is an important source of innovations. It is argued that farmers are dependent on regional sources to counteract the local tendency of cultivars to become taller and tardier. This tendency is probably the result of unintended selection for more competitive plants.

    Chapter 5 is a study of the spatial distribution of maize populations. By investigating a collection of 80 samples of maize seed from the department of Chimaltenango, and five modern varieties, it attempts to infer the seed exchange processes shaping the current spatial structure of the maize gene pool. Location, altitude, morphological, phenological, and molecular marker (SSR) data were analysed. The analysis identified altitudinal differences in the landscape as an important constraining factor in seed exchange, which is related to adaptation as measured by yield. Locally it found evidence for an isolation-by-distance effect, which points to a falling intensity of seed exchange over longer distances. However, over longer ranges (>8 km), this effect disappears. This was interpreted as evidence for the existence of different mechanisms for local and regional seed exchange. In this chapter, evidence for the influence of modern varieties is also presented. This influence was detected for the lower areas only.

    Chapter 6 argues on the basis of the findings in the preceding chapters that farmers in highland Guatemala maintain maize genetic resources in open systems. Although local seed exchange is common and is an important shaping force for the maize gene pool, occasional regional seed exchange is important in both past and present. The present spatial distribution of maize populations reflects dynamic processes and should not be conserved as such. To innovate, farmers take direct advantage of the differences between crop populations evolving in different places, in order to achieve phenotypic changes in their own fields. It is not artificial selection that is the main creative force in local innovation - the dominant view among advocates of participatory plant breeding - but the flow of seed lots in the landscape. Consequently, efforts to support seed-based innovation should not only focus on selection or local adaptation, but strengthen the capacities of innovation through seed exchange between locales. Innovation should seek to further exploit ecological complementarities between areas (and not only the representation of broader zones of ecological adaptation). For this end, new regional infrastructures to handle seeds and information may need to be created.
    Molding maize: the shaping of a crop diversity landscape in the western highlands of Guatemala
    Etten, J. van - \ 2006
    Journal of Historical Geography 32 (2006)4. - ISSN 0305-7488 - p. 689 - 711.
    domestication - intensification - ethnography - subsistence - population - conquest - indians - mexico
    Today¿s domesticated plants not only embody past humanenature interactions, but also reflect social history. Human seed exchange, replacement and loss are important forces in shaping crop diversity. This essay explores regional history in relation to the shaping of maize diversity in the western highlands of Guatemala. This is an area of exceptional maize heterogeneity and a peripheral part of the region where maize was domesticated. Maize diversity seems to have developed through geographic isolation in networks of seed exchange that were generally very local in scope. However, recent studies on Mexican maize suggest otherwise. However, few studies have examined crop diversity or seed exchange from a historical perspective. A closer examination of regional history suggests which processes might be important for shaping the present geographical distribution of maize diversity. Seeds were occasionally transported over longer distances. As a consequence, maize diversity is geographically not characterised by sharp differences between farming communities; the main differences are to be found in regional occurrences. This challenges antimodern ideas of closed, local native ecologies. Consequently, the conservation of maize genetic resources is a challenge, but not entirely contradictory with its transforming socio-economic context.
    Maíz para Guatemala : propuesta para la reactivación de la cadena agroalimentaria del maíz blanco y amarillo
    Fuentes López, M.R. ; Etten, J. van; Ortega Aparicio, A. ; Vivero, J.L. - \ 2005
    Guatemala : FAO (PESA Investigación 1) - ISBN 9789992286401 - 141 p.
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