Human–landscape interactions in the Conquezuela–Ambrona Valley (Soria, continental Iberia): From the early Neolithic land use to the origin of the current oak woodland

Abstract

We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long-standing natural stress (grazing) in a palatable tannin-producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant's condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium-grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.

The Late-Glacial and Holocene Marboré Lake sequence (2612 m a.s.l., Central Pyrenees, Spain): Testing high altitude sites sensitivity to millennial scale vegetation and climate variability

“…Many studies have demonstrated that vegetation responded differently during the beginning of the Holocene through the Iberian Peninsula, depending on their location relative to the Atlantic -Mediterranean gradient. More temperate and moister conditions were inferred from the Atlantic-influenced pollen sites (Muñoz Sobrino et al, 2005Moreno et al, 2011;Iriarte-Chiapusso et al, 2016) where a rapid spread of deciduous forest occurred, while continental and Mediterranean sequences show high proportions of pines and/or junipers (Carrión et al, 2010;Rubiales et al, 2010;Morales-Molino et al, 2013;Aranbarri et al, 2014Aranbarri et al, , 2015, indicating still intense hydrological stress due to maximum seasonality during the Early Holocene.…”

Humans take control of fire-driven diversity changes in Mediterranean Iberia’s vegetation during the mid–late Holocene

“…Neolithic settlements in the Western Mediterranean were preferentially located in semi-open vegetation (Carrión and van Geel, 1999;Ejarque et al, 2010;Revelles et al, 2015;Battentier et al, 2018), with settlement cores surrounded by extensive areas used for animal husbandry and exploitation of natural resources (García Puchol et al, 2009). Creation of new semi-open landscapes accompanied Neolithic expansion in lowlands and mountain Iberian areas (Aranbarri et al, 2015, Ejarque et al, 2010Orengo et al, 2014). Neolithic settlers apparently avoided already populated areas (Aubán et al, 2015;Zilhão, 2001), although in some places pre-existing Mesolithic communities may have assimilated Neolithic cultural elements (Bicho, 2009;García Puchol et al, 2009).…”

The historical demise of Pinus nigra forests in the Northern Iberian Plateau (south‐western Europe)

“…; Aranbarri et al . , ), with the driest episodes at 5800–5400, 4300–3800, 3100–2600, 2200–1700, 700–500 and 300 cal. bp (Carrión ; Fig.…”

“…; this paper); 3 Conquezuela (Aranbarri et al . ); 4 El Carrizal (Franco‐Múgica et al . ); 5 Camporredondo (García‐Antón et al .…”