Hydrological connectivity does change over 70 years of abandonment and afforestation in the spanish Pyrenees

24 Pags.- 7 Figs.- 3 Tabls. The definitive version is available at: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-145XRunoff connectivity depends on topography, rainfall, man-made elements (terraces, trails, roads and drainage systems) and vegetation. In this study, we quantified the effects of 70 years of human activities on runoff connectivity in the mountainous Araguás afforested sub-catchment (17·2 ha; Central Spanish Pyrenees). The IC index of hydrological connectivity was chosen to perform this metric over six land use scenarios at high spatial resolution (1 × 1 m of cell size). The current scenario (year 2012) was simulated with three flow accumulation algorithms (MD, MD8 and D8). MD8 was linked with the most frequent hydrological response of the sub-catchment (rainfall intensity and stream flow during 7 years) and generated the most representative pattern of connectivity, especially in the linear landscape elements (LLE). This algorithm was chosen to simulate five past scenarios (1945, 1956, 1973, 1980 and 2006). In all scenarios, the highest connectivity appeared related to trails and roads, as well as to streams and gullies, whereas the lowest appeared related to stonewalls in 1945 and 1956 to hillslopes in 1973, and the following afforestation. Changes in connectivity mainly depended on the changes in the vegetation factor and in a minor way in the total length, spatial location and type of LLE. Afforestation promoted lower and more stable connectivity at both local and catchment scales.This research was supported by a Marie Curie Intra-European Fellowship in the project ‘MED-AFFOREST’ (PIEF-GA-2013-624974). Dr López-Vicente acknowledges the financial support of his postdoctoral contract to the project ‘EroCostModel’ (CGL2014-54877-JIN; Programme Jóvenes Investigadores), and Dr Nadal-Romero was a recipient of a Ramón y Cajal research contract. Both contracts are of the Spanish Ministry of Economy and Competitiveness.Peer reviewe

The effects of revegetation in the natural environment and perception of the people linked to Camero Viejo (Iberian System)

During the 20th century, Euro-Mediterranean mountains underwent a process of marginalization, with high rates of emigration, land abandonment, reduction of livestock census and poor use of pasture and forest products. Marginalization, with the abandonment of most of the fields and pastures, encouraged secondary succession processes that favored the expansion of shrubs and forests. Simultaneously, the administration encouraged the reforestation of large areas for economic purposes (the increase of wood and paper pulp production) and environmental objectives (the regulation of floods and prevention of soil erosion and degra- dation). As a result of these changes, Mediterranean mountain landscapes have been simplified and homogenized, fragmentation has been reduced and many of their cultural values are being degraded, a trend that also involves the loss of local knowledge on sustainable land management. The expansion of vegetation shows other negative effects, including an increase of fire risk, a reduction in water availability, the concentration of sediment sources in ancient agricultural terraces (which maintain the most fertile and deepest soils), loss of biodiversity and problems for the economic sustainability of the mountain, due to pasture degradation, and the loss of an attractive landscape. On the other hand, we must take into account that the impacts of land use changes in mountain areas occur not only at a local scale, but also at regional and global scales, as mountain ecosystems provide a range of goods and services to the society. The aim of this study is to investigate the diversity of opinions that people linked to Camero Viejo (Iberian Range) present about the major environmental changes since the mid-twentieth century: (i) vegetation cover dynamics, (ii) soil erosion, (iii) water yield and quality, (iv) fire risk, and (v) changes in wildlife and landscape. This perception will be related to current changes, quantified from land cover and land uses maps, information taken in the administration, and literature of the study area. The final objective is to find out which social groups have a closer or unrealistic perception; in that way, decision-makers could obtain more information to develop and implement new public policies

Geoecology in Mediterranean mountain areas: a tribute to Prof. José María García-Ruiz

The origin of this special issue arose from a scientific meeting held in Logroño (Spain) in October 2014, under the theme Geoecology in extreme environments: mountains and semiarid areas (Arnáez et al., 2014). The main motivation of the event was to recognise, on the occasion of his retirement, the outstanding contribution of Prof. José María García-Ruiz to the progress of Geoecology in Mediterranean mountain areas. Prof. García-Ruiz (Zaragoza, 1949) was lecturer, between 1974 and 1987, at the University of Cáceres and La Rioja. As staff Scientist and later Professor at the Spanish National Research Council (CSIC), he was Head of the Pyrenean Institute of Ecology (IPE-CSIC) (1987–1990) and Head of the Department of Global Change at the same institute, President of the Spanish Society of Geomorphology (1994–1996), besides a productive and tireless researcher..

Soil rehabilitation in semi-arid Spain: Long-term effect of afforestation and land abandonment on soil quality

In response to the increasing amount of abandoned agricultural land in the European Mediterranean area during the last century, afforestation projects have been conducted as a measure for soil protection and ecosystem restoration. Despite the research on the impact and effectiveness of these projects, the long-term effect on soil quality has hardly been studied. Especially the linkage between soil physical, chemical and hydrological properties is lacking. An intensive fieldwork has been carried out in Murcia, southeastern Spain to study the effects of land abandonment and afforestation on soil quality along a chronosequence and included two afforested areas, planted with Pinus halepensis trees in the early ‘70s and ‘90s. Samples were taken to study changes in soil physical and chemical quality (e.g. Aggregate stability, Corg, N, P, K, Na), Soil Organic Carbon (SOC) stocks and soil hydrological properties, such as infiltration and water retention. A comparison was made between afforestation projects, abandoned agricultural plots of similar age, semi-natural vegetation and cereal crop fields. As the natural vegetation is characterized by a spotted pattern of bare areas and trees, forming so-called “islands of fertility”, both bare and vegetation covered sub-sites were included. Our results indicated that under secondary succession on abandoned fields, soil quality showed a marginal non-linear improvement over the studied period. The afforestation showed a much more pronounced linear increase, resulting in a soil quality comparable to what can be found under semi-natural vegetation. After 40 years afforestation showed to be successful in the restoration of the natural soil hydrological functioning, while the abandoned sites only indicated small changes. For this case study, in semiarid areas, afforesting is the best way forward as it has a clear effect on enhancing soil quality compared to secondary succession on abandoned agricultural fields

The application of terrestrial laser scanner and SfM photogrammetry in measuring erosion and deposition processes in two opposite slopes in a humid Badlands area (Central Spanish Pyrenees)

Erosion and deposition processes in badland areas are usually estimated using traditional observations of topographic changes, measured by erosion pins or profile metres (invasive techniques). In recent times, remote-sensing techniques (non-invasive) have been routinely applied in geomorphology studies, especially in erosion studies. These techniques provide the opportunity to build high-resolution topographic models at centimetre accuracy. By comparing different 3-D point clouds of the same area, obtained at different time intervals, the variations in the terrain and temporal dynamics can be analysed. The aim of this study is to assess and compare the functioning of terrestrial laser scanner (TLS, RIEGL LPM-321) and structure-from-motion photogrammetry (SfM) techniques (Camera FUJIFILM, Finepix x100 and software PhotoScan by AgiSoft) to evaluate erosion and deposition processes in two opposite slopes in a humid badlands area in the central Spanish Pyrenees. Results showed that TLS data sets and SfM photogrammetry techniques provide new opportunities in geomorphological erosion studies. The data we recorded over 1 year demonstrated that north-facing slopes experienced more intense and faster changing geomorphological dynamics than south-facing slopes as well as the highest erosion rates. Different seasonal processes were observed, with the highest topographic differences observed during winter periods and the high-intensity rainfalls in summer. While TLS provided the highest accuracy models, SfM photogrammetry was still a faster methodology in the field and precise at short distances. Both techniques present advantages and disadvantages, and do not require direct contact with the soil and thus prevent the usual surface disturbance of traditional and invasive methods