Enric Tello

Land abandonment, landscape, and biodiversity: questioning the restorative character of the forest transition in the Mediterranean

The effects of land abandonment on biodiversity have received considerable attention by scholars, but results are far from conclusive. Different cultural traditions of scientists seem to underlie the contrasting ways in which land abandonment is understood. Although the forest transition (FT) framework considers land abandonment as an opportunity for biodiversity conservation, European landscape ecologists characterize it as a threat. We use insights from both traditions to analyze the effects of land abandonment on landscape and biodiversity in a mountain area of metropolitan Barcelona. We do so through an in-depth historical case study covering a period of 160 years. A set of landscape metrics was applied to land-cover maps derived from cadastral cartography to characterize the landscape ecological changes brought about by land abandonment. Cadastral data on land uses were used to understand how landscape ecological changes could be explained by changing socioeconomic activities. Information on past land- management practices from semistructured interviews was used to shed light on how peasants shaped the capacity of landscape to host biodiversity. Our results point to a remarkable landscape deterioration along with the disappearance of the peasant land-use mosaics and the ensuing forest expansion. By using insights from landscape ecology in a historically informed manner, we (1) question the alleged relationship between land abandonment and ecosystem recovery; (2) show that the assumed restorative character of the FT is based on the underestimation of the ecological importance of nonforest habitats; and (3) point at a remarkable trade-off between FT and biodiversity in the Mediterranean. Finally, the case study also serves to illustrate some of the strengths and challenges of using historical approaches to land abandonment.

Water consumption in Barcelona and its regional environmental imprint: a long-term history (1717–2008)

We present the evolution of urban water withdrawal and consumption of Barcelona from the eighteenth to the twenty-first centuries. The boundaries of the urban system have been set into the limits of the current municipality, adjusting the data of earlier periods to include the estimated consumption in former municipalities aggregated to the city. Different sorts of water flows have been either recorded or estimated from scant and indirect information, such as local groundwater extractions obtained from a hydrological model calibrated with historical data on variations in the water table. The changes experienced in catching infrastructures, the regional ecological imprint of the domestic or industrial water consumed together with the rates of growth in population, economic activity and water intensity have been taken into account as driving forces. The series obtained reveal an overall increase in accessibility to safe freshwater, and a corresponding extension of water terrestrial imprints of Barcelona over the Catalan river basins, up to the peak reached in 1967–1970 both for per capita and total water withdrawn. The subsequent downward trend, mainly driven by a lesser water intensity of the local economy, a halt in population growth, and a recently link to the emergence of a New Sustainable Water Culture in Catalan society, stands out against the alleged need for new transfers from farthest basins such as the Ebro or Roine rivers.

Towards an energy–landscape integrated analysis? Exploring the links between socio-metabolic disturbance and landscape ecology performance (Mallorca, Spain, 1956–2011)

AbstractContextThe role of agricultural landscapes in biodiversity conservation is an emerging topic in a world experiencing a worrying decrease of species richness. Farm systems may either decrease or increase biological diversity, depending on land-use intensities and management. ObjectivesWe present an intermediate disturbance-complexity model (IDC) of cultural landscapes aimed at assessing how different levels of anthropogenic disturbance on ecosystems affect the capacity to host biodiversity depending on the land matrix heterogeneity. It is applied to the Mallorca Island, amidst the Mediterranean biodiversity hotspot.MethodsThe model uses the disturbance exerted when farmers alter the Net Primary Production through land-use change as well as when they remove a share of it (HANPP), together with Shannon–Wiener index (H′) of land-cover diversity. The model is tested with a twofold-scalar experimental design (1:50,000 and 1:5000) of a set of landscape units along three time points (1956, 1989, 2011). Species richness of breeding and wintering birds, taken as a biodiversity proxy, is used in an exploratory factor analysis.ResultsThe results clearly show that when intermediate levels of HANPP are performed within intermediate levels of complexity (H′) in landscape patterns, like agro-forest mosaics, great bird species richness and high socio-ecological resilience can be maintained. Yet, these complex-heterogeneous landscapes are currently vanishing due to industrial farm intensification, rural abandonment and urban sprawl.ConclusionsThe results make apparent the usefulness of transferring the concept of intermediate disturbance-complexity interplay to cultural landscapes. Our spatial-explicit IDC model can be used as a tool for strategic environmental assessment of land-use planning.

Exploring the links between forest transition and landscape changes in the Mediterranean. Does forest recovery really lead to better landscape quality

AbstractA growing number of studies argue that forest transition should be enhanced by policymakers given its potential benefits, for instance in slowing climate change through carbon sequestration. Yet the effects of forest transition in landscape heterogeneity and biodiversity remain poorly understood. In this paper we explore the relationships between the forest transition and the landscape changes occurred in a Mediterranean mountain area. Historical land-use maps were built from cadastral cartography (1854; 1956; 2012). Metrics on land-cover change, landscape structure, and landscape functioning were calculated. Multiyear data on butterfly assemblages from two transects (1994–2012) was used as indicator of land-use change effects on biodiversity. Results show a forest expansion process in former cereal fields, vineyards and pasturelands along with rural out-migration and land abandonment. Such forest transition involved large changes in landscape structure and functioning. As peasant management of integrated agrosilvopastoral systems disappeared, landscape became less diverse. Even if forest area is now larger than in mid-nineteenth century, ecological connectivity among woodland did not substantially improve. Instead, ecological connectivity across open habitats has greatly decreased as cereal fields, vineyards, meadows and pasturelands have almost disappeared. Butterfly assemblages under changing land-uses highlights the importance of agro-forest mosaics not only for these species but for biodiversity at large in the last decades. Our work emphasizes that conservation of landscapes with a long history of human use needs to take into account the role of humans in shaping ecological features and biodiversity. Hence the suitability of forest transitions should be critically examined in relation to context and policy objectives.

From vineyards to feedlots: a fund-flow scanning of sociometabolic transition in the Vallès County (Catalonia) 1860–1956–1999

We analyse the changes to agricultural metabolism in four municipalities of Vallès County (Catalonia, Iberia) by accounting for their agroecosystem funds and flows during the socioecological transition from organic to industrial farming between the late nineteenth and twentieth centuries. The choice of three different stages in this transition allows us to observe the transformation of its funds and flows over time, the links established between them and the effect on their energy profiles. We emphasize the relevance of the integration and consistency of agroecosystem funds for energy efficiency in agriculture and their role as underlying historical drivers of this socioecological transition. While readjustment to market conditions and availability and affordability of external inputs are considered the main drivers of the transition, we also highlight the role of societal energy and nutritional transitions. An analysis of advanced organic agriculture c. 1860 reveals the great effort required to reproduce soil fertility and livestock from the internal recirculation of biomass. Meanwhile, a balance between land produce and livestock densities enabled the integration of funds, with a positive impact on energy performance. The adoption of fossil fuels and synthetic fertilizers c. 1956 reduced somewhat the pressure exerted on the land by overcoming the former dependence on local biomass flows to reproduce the agroecosystem. Yet external inputs diminished sustainability. Partial dependence on external markets existed congruently with internal crop diversity and the predominance of organic over industrial farm management. A shift towards animal production and consumption led to a new specialization process c. 1999 that resulted in crop homogenization and agroecological landscape disintegration. The energy returns of this linear feed-food livestock bioconversion declined compared to earlier mixed farming. Huge energy flows driven by a globalized economy ran through this agroecosystem, provoking deep impacts at both a local and external scale.

The Onset of the English Agricultural Revolution: Climate Factors and Soil Nutrients

The English Agricultural Revolution began during a period of climate change in which temperatures decreased significantly. Lower temperatures meant less bacterial activity, a slower release of mineral nitrogen into cultivated soils, and a shorter growing season for crops—a combination that tended to diminish yields. The English farmers reacted by increasing the flow of organic matter and manure into the soil, thus mitigating the negative effect of the colder temperatures to some extent. When the temperatures rose again, the faster mineralization of soil organic matter led to bountiful yields that encouraged English farmers to continue with these innovative strategies. The upshot is that the English agricultural revolution was more a discovery than an invention, that the English agricultural revolution was more a discovery than an invention, induced by a combination of climate challenges, social and institutional settings, and market incentives.

Does Your Landscape Mirror What You Eat? A Long-Term Socio-metabolic Analysis of a Local Food System in Vallès County (Spain, 1860–1956–1999)

We assess the social metabolism of very different farm systems that existed in Valles County, along the socio-ecological transition from organic to industrial agriculture at three different time points from 1860 to 1999. This allows us to analyze these contrasting food systems by focusing on four perspectives: agricultural labour productivity in relation to regional diets, the importance of multi-functionality in agroecosystems, the loss of landscape diversity and species richness, and the impacts of the current food regime at global and local scales. The socio-metabolic profiles obtained show that (1) winegrowing specialization co-existed with sustenance-oriented organic farming in 1860; (2) in 1956, the resumption of grain growing, combined with incipient use of industrial fertilizers, led to a more diverse agroecosystem where greater dependence on external inputs was countered by an increased productivity, providing more balanced diets and producing minor impacts on landscape ecology; (3) by 1999, a specialization in feedlots had disconnected local diets from a linear agro-industrial feed-meat chain based on huge feed imports from the Global South, leading to highly polarized socio-ecological impacts. Whereas unequal ecological exchange affects peasant communities and agroecosystems in feed-exporting countries, local landscapes suffer from the accumulation of dung waste poured into flatlands and from forest abandonment in steeper areas.

A long-term view of water consumption in Barcelona (1860–2011): from deprivation to abundance and eco-efficiency?

Water consumption in Barcelona in Spain, and the corresponding water imprint, followed a path resembling an Environmental Kuznets Curve. They grew slowly from the mid-19th century before reaching a peak in 1967–70, and a downward trend followed up to 2010. This paper uses a decomposition analysis to assess the role played by population growth, income increase and water intensity as determinants of these trends. It is stressed that water intensity does not express technical change alone, but includes social inequalities, consumer habits and cultural perceptions as well. It can be explained by taking into account the social conflicts and public policies of each period.

A landscape ecology assessment of land-use change on the Great Plains-Denver (CO, USA) metropolitan edge

For better or worse, in those parts of the world with a widespread farming, livestock rising, and urban expansion, the maintenance of species richness and ecosystem services cannot depend only upon protected natural sites. Can they rely on a network of cultural landscapes endowed with their own associated biodiversity? We analyze the effects of land-cover change on landscape ecological patterns and processes that sustain bird species richness associated to cropland-grassland landscapes in the Great Plains-Denver metropolitan edge. Our purpose is to assess the potential contribution to bird biodiversity maintenance of Great Plain’s cropland-grassland mosaics kept as farmland green belts in the edge of metropolitan areas. We present a quantitative landscape ecology assessment of land-cover changes (1930–2010) experienced in five Great Plains counties in Colorado. Several landscape metrics assess the diversity of land-cover patterns and their impact on ecological connectivity indices. These metrics are applied to historical land-cover maps and datasets drawn from aerial photos and satellite imagery. The results show that the cropland-grassland mosaics that link the metropolitan edge with the surrounding habitats sheltered in less human-disturbed areas provide a heterogeneous land matrix were a high bird species richness exists. They also suggest that keeping multifunctional farmland-grassland green belts near the edge of metropolitan areas may provide important ecosystem services, supplementing traditional conservation policies. Our maps and indicators can be used for selecting certain types of landscape patterns and priority areas on which biodiversity conservation efforts and land-use planning can concentrate.

More than energy transformations: a historical transition from organic to industrialized farm systems in a Mediterranean village (Les Oluges, Catalonia, 1860–1959–1999)

ABSTRACT The analysis of energy efficiency of agroecosystems from a sociometabolic perspective is a useful way to assess the sustainability of farm systems. In this paper we examine the transition of a Mediterranean agroecosystem from an organic farm system in the mid nineteenth century to an industrialized one at the end of the twentieth century by means of the technologies and ideology of the Green Revolution. Given that many of the world’s agricultural systems have experienced, or are currently experiencing this transformation, our results are relevant for building more sustainable agricultural systems in future. Our results highlight the relevance of livestock density, and the flows of biomass reused and unharvested biomass as key elements affecting the sustainability of the agroecosystem not only from a socioeconomic perspective, but also from an agroecological point of view. Additionally, from a biocultural perspective our investigation sustains the relevance of the study of traditional farm systems for the development of a sustainable agriculture.