Climatic signals in growth and its relation to ENSO events of two Prosopis species following a latitudinal gradient in South America

Abstract

Semiarid environments throughout the world have lost a major part of their woody vegetation and biodiversity due to the effects of wood cutting, cattle grazing and subsistence agriculture. The resulting state is typically used for cattle production, but the productivity of these systems is often very low, and erosion of the unprotected soil is a common problem. Such dry-land degradation is of great international concern, not only because the resulting state is hardly productive but also because it paves the way to desertification. The natural distribution of the genus Prosopis includes arid and semiarid zones of the Americas, Africa and Asia, but the majority of the Prosopis species are, however, native to the Americas. In order to assess a likely gradient in the response of tree species to precipitation, temperature and their connection to El Niñ o southern oscillation (ENSO) events, two Prosopis species were chosen along a latitudinal gradient in Latin America, from northern Peru to central Chile: Prosopis pallida from a semi-arid land in northern and southern Peru and P. chilensis from a semiarid land in central Chile. Growth rings of each species were crossdated at each sampling site using classical dendrochronological techniques. Chronologies were related with instrumental climatic records in each site, as well as with SOI and N34 series. Cross-correlation, spectral and wavelet analysis techniques were used to assess the relation of growth with precipitation and temperature. Despite the long distance among sites, the two Prosopis species presented similar responses. Thus, the two species' growth is positively correlated to precipitation, while with temperature it is not. In northern Peru, precipitation and growth of P. pallida present a similar cyclic pattern, with a period of around 3 years. On the other hand, P. pallida in southern Peru, and P. chilensis also present this cyclic pattern, but also another one with lower frequency, coinciding with the pattern of precipitation. Both cycles are within the range of the ENSO band.

Annual variation and influence of climate on the ring width and wood hydrosystem of Prosopis flexuosa DC trees using image analysis

“…Dendrochronological studies using Prosopis have presented different levels of correlation between their tree-ring series; this large variability likely reflects the broad plasticity and adaptability of Prosopis trees to different environmental conditions (Villalba et al 2000). For example, López et al (2006) developed three chronologies for Prosopis pallida HBK in Peru and one of Prosopis chilensis (Mol.) Stuntz in Chile.…”

The role of ecophysiological studies in the genus Prosopis: implications for the conservation of drought-prone species

“…Additionally, there is no general consensus that explains the low natural regeneration rates of individuals of the genus Prosopis (Carevic et al, 2012). Previous studies have concluded that regeneration rates are extremely low, mainly due to periods in which the ENSO (El Niño-Southern Oscillation) phenomenon is active, which induces erratic behavior in the natural germination of seeds (López et al, 2006). During the ENSO phenomenon it appears that the main physiological trait that supports plant survival is deeper root growth (Squeo et al, 2007).…”

CLIMATE-TREE GROWTH RELATIONSHIPS OF Mimosa tenuiflora IN SEASONALLY DRY TROPICAL FOREST, BRAZIL

“…The effects of rainfall variation in semi-arid Brazil, taking into account population growth and demands for land use have been modeled by Barbieri et al (2010) and Krol and Bronstert (2007). Intense dry events have been attributed to "El Niño" (SILVA, 2004), and can be recognized by examination of growth ring patterns in dry forest species (BRIENEN et al, 2010;FICHTLER et al, 2004;GEBREKIRSTOS et al, 2008;LOPEZ et al, 2006;RODRIGUEZ et al, 2005).…”

“…Therefore, there are two causes that could explain the different behavior in this area. Lopez et al (2006) studied the growth response to rainfall, temperature and El Niño (ENSO) in two naturally occurring species along the latitudinal gradient from Peru (Prosopis pallida) to central Chile (Prosopis chilensis). Despite the distance between the locations, the growth of the two species had similar positive correlations with rainfall.…”