Variations in growth, survival and carbon isotope composition ( 13C) among Pinus pinaster populations of different geographic origins

Abstract

To evaluate differences in growth and adaptability of maritime pine (Pinus pinaster Ait.), we studied growth, polycyclism, needle tissue carbon isotope composition (delta(13)C) as an estimate of water-use efficiency (WUE) and survival of seven populations at 10 years of age growing in a performance trial at a provenance test site in Escaroupim, Portugal. Six populations were from relatively high rainfall sites in Portugal and southwestern France (Atlantic group), and one population was from a more arid Mediterranean site in Spain. There were significant differences between some populations in total height, diameter at breast height, delta(13)C of bulk needle tissue, polycyclism and survival. A population from central Portugal (Leiria, on the Atlantic coast) was the tallest and had the lowest delta(13)C. Overall, the variation in delta(13)C was better explained by the mean minimum temperatures of the coldest month than by annual precipitation at the place of origin. Analyses of the relationships between delta(13)C and growth or survival revealed a distinct pattern for the Mediterranean population, with low delta(13)C (and WUE) associated with the lowest growth potential and reduced survival. There were significant negative correlations between delta(13)C and height or survival in the Atlantic group. Variation in polycyclism was correlated with annual precipitation at the place of origin. Some Atlantic populations maintained a high growth potential while experiencing moderate water stress. A detailed knowledge of the relationships between growth, survival and delta(13)C in contrasting environments will enhance our ability to select populations for forestry or conservation.

Phenotypic plasticity in Pinus pinaster δ13C: environment modulates genetic variation

“…Inter-and intra-population variation in δ 13 C δ 13 C variation between our populations was 1.26% in the xeric site and 0.60% in the mesic site, which is in the range of previous P. pinaster observations (Correia et al, 2008). As a result, we only found δ 13 C differentiation of populations in the xeric site (Tab.…”

“…Correia et al (2008) observed minor but significant δ 13 C differences between populations in a subhumid trial site. However, the populations from the driest and more humid origins displayed equal δ 13 C values, which is in agreement with our results in the mesic trial site.…”

“…Despite the mean annual precipitation of the geographic origin of M is high, the location is very windy, which could cause high vapor pressure deficit around the needles, and the soils are sandy with low water retention. These environmental factors could have played a role in the drought resistance displayed by M. Furthermore, in a previous study, the population from the French Landes exhibited the highest δ 13 C among one Mediterranean and six Atlantic P. pinaster populations (Correia et al, 2008). They explained the higher WUE of the Landes population by its adaptive evolution.…”

“…In a single trial site, the relationship between δ 13 C and growth showed different patterns depending on the origin of the maritime pine populations. Low δ 13 C values were associated to low height in a Mediterranean population and to high height in the Atlantic populations (Correia et al, 2008).…”

“…Previous studies in P. pinaster obtained δ 13 C variation at a population level (Correia et al, 2008), family level (Fernandez et al, 2006), and both, population and family level (Aranda et al, 2010). We analyzed the intra-specific variability of δ 13 C at the inter-and intra-population levels.…”