Grasslands in ‘Old World’ and ‘New World’ Mediterranean‐climate zones: past trends, current status and future research priorities

Abstract

Despite their ecological, economic and social importance, grasslands in areas with Mediterranean climates continue to receive limited scientific, political and media attention. The main objectives of this review are to compare and contrast dryland grasslands in the ‘Old World’ regions of the Mediterranean basin (southern Europe, western Asia and North Africa) with those of ‘New World’ regions with Mediterranean climates (Australia and Chile) and to identify common research priorities. The common characteristics and differences in climate, soils, native vegetation, importance of the livestock sector and the socio‐economic background for the different Mediterranean environments are examined. Past trends and the current status of temporary and permanent Mediterranean grasslands are also described. Some common issues between these regions are as follows: (i) adaptation to climate change; (ii) increasing persistence and drought survival of both annual and perennial species; (iii) the important role of forage legumes; (iv) maintaining grassland plant diversity; and (v) improved ecosystem services, such as carbon sequestration, control of soil erosion and wildfires, and preservation of both wild and domestic biodiversity. The favourable climate in these regions, which allows year‐round grazing and the growth of legumes, should be exploited to improve the sustainability of grassland‐based, extensive farming systems and the quality of their animal products, while at the same time improving ecosystem services. The decreasing support for grassland research and development programmes requires increased international scientific and technical cooperation among the few institutions operating in the different Mediterranean‐climate areas of the World to provide innovative and sustainable solutions to farmers.

Impacts of Global Change on Mediterranean Forests and Their Services

“…The history of Mediterranean grasslands differs greatly from the current situation in various areas of the world [173]. Grassland covers about 35% of the total surface in the northern Mediterranean area [173].…”

How can forage production in Nordic and Mediterranean Europe adapt to the challenges and opportunities arising from climate change?

“…Both temporary and permanent grasslands may be harvested by mowing (meadows), grazing (pastures) or a combination, and consist of perennial, biennial and/or annual forage species, mainly grasses and legumes. Overviews of grassland production in the Nordic and Mediterranean regions of Europe were recently given by Helgadóttir et al (2014) and Porqueddu et al (2016). Nordic grasslands are dominated by perennial grasses, with a few perennial legume species also present.…”

“…oat (Avena sativa L.), italian ryegrass (L. multiflorum Lam. ), crimson clover (T. incarnatum L.), egyptian clover (T. alexandrinum L.), common vetch (Vicia sativa L.)) (Annicchiarico et al, 2013;Porqueddu et al, 2016). Despite an increasing use of annual self-reseeding species (mainly subterranean clover (T. subterraneaum L.) and Medicago spp.)…”

“…Despite an increasing use of annual self-reseeding species (mainly subterranean clover (T. subterraneaum L.) and Medicago spp.) for pasture improvement in dry environments (Porqueddu and Gonzalez, 2006), cultivars available in the seed market have often proved to be poorly adapted to the climatic conditions and management systems of Mediterranean Europe (Sulas, 2005;Salis et al, 2012;Porqueddu et al, 2016). Native genotypes of these species (e.g., rigid ryegrass (L. rigidum Gaud.)…”

“…Based on the predicted changes in precipitation, with an overall reduced growth period in the driest Mediterranean regions, annual species will need earlier seed maturation for reliable seed set in shorter growing seasons, as well as mechanisms (i.e. regulation of seed dormancy and germination) ensuring the presence of a seedbank under the expected seasonal patterns of temperature and water availability (Porqueddu et al, 2016). A low requirement for dormancy release gives the potential for early germination and higher yield, but at the risk of seedling mortality due to false breaks.…”