Debris-flow activity in abandoned channels of the Manival torrent reconstructed with LiDAR and tree-ring data

Hydrogeomorphic processes are a major threat in many parts of the Alps, where they periodically damage infrastructure, disrupt transportation corridors or even cause loss of life. Nonetheless, past torrential activity and the analysis of areas affected during particular events remain often imprecise. It was therefore the purpose of this study to reconstruct spatio-temporal patterns of past debris-flow activity in abandoned channels on the forested cone of the Manival torrent (Massif de la Chartreuse, French Prealps). A Light Detecting and Ranging (LiDAR) generated Digital Elevation Model (DEM) was used to identify five abandoned channels and related depositional forms (lobes, lateral levees) in the proximal alluvial fan of the torrent. A total of 156 Scots pine trees (Pinus sylvestris L.) with clear signs of debris flow events was analyzed and growth disturbances (GD) assessed, such as callus tissue, the onset of compression wood or abrupt growth suppression. In total, 375 GD were identified in the tree-ring samples, pointing to 13 debris-flow events for the period 1931–2008. While debris flows appear to be very common at Manival, they have only rarely propagated outside the main channel over the past 80 years. Furthermore, analysis of the spatial distribution of disturbed trees contributed to the identification of four patterns of debris-flow routing and led to the determination of three preferential breakout locations. Finally, the results of this study demonstrate that the temporal distribution of debris flows did not exhibit significant variations since the beginning of the 20th century.

Surgical technique: The capsular arthroplasty: a useful but abandoned procedure for young patients with developmental dysplasia of the hip

Codivilla in 1901, Hey Groves in 1926, and Colonna in 1932 described similar capsular arthroplasties--wrapping the capsule around the femoral head and reducing into the true acetabulum--to treat completely dislocated hips in children with dysplastic hips. However, these procedures were associated with relatively high rates of necrosis, joint stiffness, and subsequent revision procedures, and with the introduction of THA, the procedure vanished despite some hips with high functional scores over periods of up to 20 years. Dislocated or subluxated hips nonetheless continue to be seen in adolescents and young adults, and survival curves of THA decrease faster for young patients than for patients older than 60 years. Therefore, joint preservation with capsular arthroplasty may be preferable if function can be restored and complication rates reduced.

Indigenous land reconfiguration and fragmented institutions: a historical political ecology of Tsimane’ lands (Bolivian Amazon)

Lands inhabited by indigenous peoples often have low population density but abundant natural resources. For those reasons, many actors have historically attempted to occupy those lands or use the resources in them. Increasing pressures over lands occupied by indigenous peoples have resulted in the awakening of indigenous peoples over their rights to land and resources generating many debates over indigenous peoples' rights to land and self-governance. In this article, we provide a historical and geographical overview of territorial and governance issues among the Tsimane', an indigenous group native to the Bolivian Amazon. We examine how the Bolivian state economic policies implemented during the 20th century affected the Tsimane' ancestral lands, and how – over the late-20th century – the Bolivian state accommodated Tsimane' claims to lands in between multiple interests. We show how national policies led to the reconfiguration of Tsimane' territoriality and to a fragmented institutional representation. Current indigenous territories and indigenous political representation are an expression of conflictive policies that have involved multiple actors and their specific interests on indigenous lands and its resources.

Marginal lands or marginal people? Analysing key processes determining the outcomes of large-scale land acquisitions in Lao PDR and Cambodia

This chapter aims to overcome the gap existing between case study research, which typically provides qualitative and process-based insights, and national or global inventories that typically offer spatially explicit and quantitative analysis of broader patterns, and thus to present adequate evidence for policymaking regarding large-scale land acquisitions. Therefore, the chapter links spatial patterns of land acquisitions to underlying implementation processes of land allocation. Methodologically linking the described patterns and processes proved difficult, but we have identified indicators that could be added to inventories and monitoring systems to make linkage possible. Combining complementary approaches in this way may help to determine where policy space exists for more sustainable governance of land acquisitions, both geographically and with regard to processes of agrarian transitions. Our spatial analysis revealed two general patterns: (i) relatively large forestry-related acquisitions that target forested landscapes and often interfere with semi-subsistence farming systems; and (ii) smaller agriculture-related acquisitions that often target existing cropland and also interfere with semi-subsistence systems. Furthermore, our meta-analysis of land acquisition implementation processes shows that authoritarian, top-down processes dominate. Initially, the demands of powerful regional and domestic investors tend to override socio-ecological variables, local actors’ interests, and land governance mechanisms. As available land grows scarce, however, and local actors gain experience dealing with land acquisitions, it appears that land investments begin to fail or give way to more inclusive, bottom-up investment models.

Dispersal and microsite limitation in an abandoned calcareous grassland of the southern prealps

Dispersal limitation is often involved when the species composition of a dry abandoned grassland shows a slow response to resumed regular mowing. A seed-addition experiment, using 32 species which do not belong to the local species pool, was performed on Monte San Giorgio (southern Switzerland) to test whether the low recruitment success was due to dispersal limitation or due to unfavourable microsite conditions. In October 1997, 20 species were individually sown in six 3 × 4 m blocks of a 2 × 2 factorial “partial” split-plot design with treatments of abandonment vs. mowing and undisturbed vs. root-removed soil, this last being applied in small naturally-degradable pots. Moreover, 12 species were sown only in the treatments on undisturbed soil. Seedlings of sown and spontaneously germinating seeds were observed on 16 occasions over one 12-month period. Seeds of 31 out of the 32 species germinated. Twenty-four species showed germination rates higher than 5% and different seasonal germination patterns. Established vegetation, especially the tussocks ofMolinia arundinacea, reduced the quality of microsites for germination. Whereas a few species germinated better under the litter ofMolinia arundinacea, many more germinated better under the more variable microsite conditions of a mown grassland. Only a few seedlings of 25 species out of the 31 germinated species survived until October 1998. Seedling survival was negatively affected by litter, unfavourable weather conditions (frost and dry periods followed by heavy rains) and herbivory (slugs and grasshoppers). Tussocks ofMolinia arundinacea, however, tended to protect seedlings. The poor establishment success of “new” species observed in abandoned meadows on Monte San Giorgio after resumed mowing is due to dispersal and microsite limitations.