Climate/Water-Cycle Feedbacks in the Mediterranean: The role of Land-Use Changes and the Propagation of Perturbations at the Regional and Global Scale

Author(s):  
Millán M. Millán
Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 240
Author(s):  
Alessandro Ferrarini ◽  
Marco Gustin ◽  
Claudio Celada

Biodiversity loss has multiple causes, but habitat degradation through land-use change is the predominant driver. We investigated the effectiveness of the Natura 2000 network in preserving the main wetlands of the two largest islands of the Mediterranean region, whose conservation is critical for many avian species at European and global level, in a 23-year period (1990–2012). In Sardinia, the surroundings of 22 wetlands were affected by an increase in artificial areas (+64 ha/year) and decrease in agricultural (−54 ha/year) and natural (−17 ha/year) ones. In Sicily, the surroundings of 16 wetlands were impacted by an increase in agricultural areas (+50 ha/year) and decrease in natural and semi-natural ones (−62 ha/year). Results show that the Natura 2000 policies were effective in preserving wetlands (no shrinkages detected in both regions), but their surroundings experienced intense processes of degradation and artificialization in all the sub-periods considered (1990–2000, 2000–2006, 2006–2012), whose effects are now threatening waterbirds and wetland integrity. The enlargement of the existing Natura 2000 sites, the creation of new ones and the speedup of the application of the rules of the Habitats and Birds Directives seem necessary to counteract the rapid land-use changes around these important stopover sites.


Botany ◽  
2020 ◽  
Vol 98 (9) ◽  
pp. 479-488
Author(s):  
Francisco E. Fontúrbel

Mistletoes are a group of flowering plants that have developed a parasitic lifeform through complex eco-evolutionary processes. Despite being considered a pest, mistletoes represent a keystone forest resource and are involved in complex plant–plant and plant–animal interactions. Their parasitic lifeform and specialized ecological interactions make mistletoes an ideal model with which to understand the effects of anthropogenic disturbances in a changing world. The accelerated growth of the human population has altered all ecosystems on Earth, leading to biodiversity loss. Land-use changes (involving habitat loss, fragmentation, degradation, and transformation processes) can alter the ecological scenario for mistletoe by altering hosts, mutualists, and nutrient cycling. Those changes may have large consequences at the community level, changing the spatial structure of mistletoes, as well as interaction effectiveness, facilitation process, interaction disruption, and novel interactions with invasive species, leading to non-analog communities in the long run. Furthermore, climate change effects operate on a global scale, enhancing the effects of land-use changes. As temperatures increase, many species would alter their distribution and phenology, potentially causing spatial and temporal mismatches. But more critical is the fact that water stress is likely to disrupt key ecological interactions. Thus, mistletoes can provide valuable insights for what we can expect in the future, as a result of human disturbances.


2014 ◽  
Vol 5 (2) ◽  
pp. 204-215 ◽  
Author(s):  
M. Velasco ◽  
À. Cabello ◽  
I. Escaler ◽  
J. I. Barredo ◽  
A. Barrera-Escoda

Global change, including climate, land-use and socio-economic changes, is expected to increase the stress on the entire water cycle. In the Mediterranean region, extreme events are likely to increase due to climate change. This work, framed in the EC Seventh Framework Programme project IMPRINTS, presents a methodology to obtain future flood risk maps using climate and land-use scenarios, identifying the new potential risk zones. The implementation of this methodology is applied to the Llobregat river basin case study. Two different special report on emission scenarios are used, and although the uncertainties are high, the results obtained are coincident: an increase of flood risk is observed in the whole Low Llobregat area. The climate changes affect the basin globally, increasing the risk homogeneously within the area considered. On the other hand, land-use changes represent urban growth in the floodplains, and hence, local risk increases are found in these spots.


Author(s):  
Sonia I. Seneviratne ◽  
Richard Wartenburger ◽  
Benoit P. Guillod ◽  
Annette L. Hirsch ◽  
Martha M. Vogel ◽  
...  

This article investigates projected changes in temperature and water cycle extremes at 1.5°C of global warming, and highlights the role of land processes and land-use changes (LUCs) for these projections. We provide new comparisons of changes in climate at 1.5°C versus 2°C based on empirical sampling analyses of transient simulations versus simulations from the ‘Half a degree Additional warming, Prognosis and Projected Impacts’ (HAPPI) multi-model experiment. The two approaches yield similar overall results regarding changes in climate extremes on land, and reveal a substantial difference in the occurrence of regional extremes at 1.5°C versus 2°C. Land processes mediated through soil moisture feedbacks and land-use forcing play a major role for projected changes in extremes at 1.5°C in most mid-latitude regions, including densely populated areas in North America, Europe and Asia. This has important implications for low-emissions scenarios derived from integrated assessment models (IAMs), which include major LUCs in ambitious mitigation pathways (e.g. associated with increased bioenergy use), but are also shown to differ in the simulated LUC patterns. Biogeophysical effects from LUCs are not considered in the development of IAM scenarios, but play an important role for projected regional changes in climate extremes, and are thus of high relevance for sustainable development pathways.This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.


Author(s):  
Dedy Miswar ◽  
Listumbinang Halengkara ◽  
I Gede Sugiyanta ◽  
Ahmad Sahid Al Azhari

Ambarawa District has allegedly experienced many changes in land use. Changes in land use in Ambarawa District are dominated by changes in agricultural land to non-agricultural land. This is because the land in Ambarawa District is influenced by the role of its inhabitatns in utilizing the land so that it has an impact on land use change. This study aims to determine changes in land use, the factors that influence land use changes, the direction of development and what types of use changes are most dominant in Ambarawa District, Pringsewu Regency. The method used in this research is survei and image interpretation by looking at changes in land use in each area. The population used in this study were all villages in Ambarawa District, totaling 8 villages which were suspected of experiencing changes in land use. Collecting data in this study is a descriptive geospatial approach through the overlay technique of land use spatial data. The results showed that there was a change in land use in Ambarawa District year 2014-2019 covering an area of 2.195,8 ha (70,83%), which was caused by social and economic factors, namely the increase in population and workers and the direction of land use changes to the west and east.


2019 ◽  
Vol 146 (2) ◽  
pp. 145-170
Author(s):  
Carla K. M. Nantke ◽  
Patrick J. Frings ◽  
Johanna Stadmark ◽  
Markus Czymzik ◽  
Daniel J. Conley

AbstractSi fluxes from the continents to the ocean are a key element of the global Si cycle. Due to the ability of coastal ecosystems to process and retain Si, the ‘coastal filter’ has the potential to alter Si fluxes at a global scale. Coastal zones are diverse systems, sensitive to local environmental changes, where Si cycling is currently poorly understood. Here, we present the first palaeoenvironmental study of estuarine biogenic silica (BSi) fluxes and silicon isotope ratios in diatoms (δ30Sidiatom) using hand-picked diatom frustules in two sediment cores (CBdist and CBprox) from the Chesapeake Bay covering the last 12000 and 8000 years, respectively. Constrained by the well-understood Holocene evolution of the Chesapeake Bay, we interpret variations in Si cycling in the context of local climate, vegetation and land use changes. δ30Sidiatom varies between + 0.8 and + 1.7‰ in both sediment cores. A Si mass balance for the Chesapeake Bay suggests much higher rates of Si retention (~ 90%) within the system than seen in other coastal systems. BSi fluxes for both sediment cores co-vary with periods of sea level rise (between 9500 and 7500 a BP) and enhanced erosion due to deforestation (between 250 and 50 a BP). However, differences in δ30Sidiatom and BSi flux between the sites emphasize the importance of the seawater/freshwater mixing ratios and locally variable Si inputs from the catchment. Further, we interpret variations in δ30Sidiatom and the increase in BSi fluxes observed since European settlement (~ 250 a BP) to reflect a growing human influence on the Si cycle in the Chesapeake Bay. Thereby, land use change, especially deforestation, in the catchment is likely the major mechanism.


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