Climate effects on growth differ according to height and diameter along the stem in Pinus pinaster Ait.

Abstract

Climate-growth relationships in forest trees are increasingly the focus of research aimed at understanding and assessing responses to climate change. Many studies have been confined to annual radial growth at breast height as an easy-to-measure dendrological standard variable, although its validity as a proxy for overall annual growth patterns in trees has scarcely been addressed. In this study, we test this hypothesis by exploring additional information on climate-growth relationships as well as analyzing both the radial growth at different stem heights and the height increment. For this purpose, past annual radial growth and shoot elongation were measured in 10 dominant Pinus pinaster Ait. trees in a 130-year-old stand. Radial increments were measured on disks taken from five different trunk heights up to 15 meters. Height increments were obtained by measuring the distance between consecutive branch whorls, which appear as knots after sawing a longitudinal section of the stem. The relationships between climate and both radial growth and height increment were analyzed through Pearson's correlations and the response to extreme climatic episodes was analyzed using resilience indices. Results revealed that the climatic variables affecting growth were different for height and stem diameter. Additionally, in the case of stem diameter, the climatic variables affecting growth also depended on the height at which the sample was taken. Precipitation prior to bud break, both in the year in which the studied shoot elongation takes place and in the previous year, has a positive effect on height increment. Radial growth in the upper part of the stem was mainly influenced by spring temperatures and precipitation, whereas in the case of basal radial growth it was the autumn and winter temperatures and precipitation of the previous year to growth which had the greatest influence. Similarly, severe droughts cause greater decline in height increment, while the decline in radial growth of the upper part of stem is smaller than that of radial growth at breast height. In conclusion, the analysis of height increment and upper radial growth provides important information to complement the dendroclimatology data for radial growth at breast height, thus improving our understanding of the impact of climate change on tree growth.

The Impact of Drought Stress on the Height Growth of Young Norway Spruce Full-Sib and Half-Sib Clonal Trials in Sweden and Finland

“…This indicated that the carry-over effects of the 2018 drought stress might have negatively influenced the recovery of the trees in 2019. One possible explanation for this might be that the height and radial increment in most conifers is mainly predetermined during the year previous to the growth [44]. There was also an obvious structural reason; with the cessation of growth and bud set, the newly formed bud starts to form needle primordia for the next growing season whereafter it enters an endodormant state [45].…”

Scots pine plantations growth adaptation to climate warming in locations at the southernmost distribution limit of the species

“…where BAI i is the BAI value of the i year. These indices were calculated with 4-year pre-(i-4), and post-disturbance (i+4) periods, based on previous studies (Rubio-Cuadrado et al, 2018b, 2018a, using the pointRes package in R (van der Maaten-Theunissen et al, 2015). The differences between sites were analyzed through Mann-Whitney U tests.…”

Gestión forestal para la adaptación al cambio global. Evaluación de tratamientos selvícolas para la diversificación y regeneración de masas de repoblación

“…El crecimiento difiere en las dos estaciones estudiadas (primavera y otoño), siendo mayor en primavera que en otoño (que incluye también el parón veraniego), aunque la meteorología solo afecta al crecimiento primario primaveral. Estudios previos han señalado que P. pinaster se comporta como una especie policíclica (Rubio-Cuadrado et al, 2018;Vieira et al, 2019;Aldea et al, 2021), por lo que nuestros resultados confirman este hecho. La mayor duración de las sequías estivales que se prevé con el cambio climático en la cuenca del Mediterráneo tendrá como consecuencia la reducción de la ventana de crecimiento primaveral, lo que afectará al desarrollo del regenerado (Chambel et al, 2007;Ruano et al, 2009, entre otros).…”

“…En cuanto al crecimiento del regenerado de esta especie, las coníferas mediterráneas, como es el pino resinero, suelen presentar un patrón bimodal de actividad en el cambium y los tejidos meristemáticos, que se encuentra frecuentemente modulado por las condiciones climáticas y les lleva a generar dos ciclos anuales de crecimiento diametral y en altura (Jordy, 2004;Rubio-Cuadrado et al, 2018;Aldea et al, 2021). Además del control climático del crecimiento (Ruano et al, 2009), se han encontrado influencias de la competencia inter e intra-específica (Calama et al, 2017), de características intrínsecas de la planta, como su propio tamaño o el estado ontogénico (de la Mata et al, 2014) y del tratamiento selvícola escogido (Rodríguez- García et al, 2010).…”

“…Además, el tamaño de bosquete y la posición dentro del mismo son variables adicionales a tener en cuenta cuando se utiliza la entresaca por bosquetes (Muscolo et al, 2014). No obstante, las coníferas mediterráneas, como P. pinaster, presentan un patrón bimodal de actividad meristemática y en el cambium modulado por las condiones climáticas, generando por tanto dos ciclos de crecimiento en altura y diámetro durante el año, uno en primavera y otro en otoño (Jordy, 2004;Rubio-Cuadrado et al, 2018;Aldea et al, 2021). Por tanto, la modelización estadística de estos dos ciclos de crecimiento puede ser más complicada, lo que ha llevado a que se hayan modelizado totalmente por separado, o con la ayuda de otros métodos como los modelos dobles de Richards (Aldea et al, 2021).…”