Forest growth and climate change: evidences from the ICP-Forests intensive monitoring in Italy

Abstract

A few concurrent and/or counteracting factors (increase of average air temperature, rainfall shortage, drought, CO2 enrichment, ozone, nitrogen fertilization, sulphate deposition) drive today the soil-tree-atmosphere relationships in the Mediterranean area. Radial stem growth measured within the ICP-Forests level II Italian network provides a sensitive response to these occurrences. Climate fluctuations and repeated anomalous seasons or extreme events are the major evidences of the change in progress. The 2003 heat wave is the main event occurred in this decade over large part of Europe. In Italy, it provoked a marked water deficit coupled to high air temperature, which resulted in a heavy water stress. The growth performance in different forest types was analyzed in this paper: growth rate in 2000-2004, compared with 1997-1999, showed reductions up to 50% on half of the plots examined. Most of them were: (i) in northern-central Italy within the southern continental border of the climatic deviation; (ii) at low elevation, which is more sensitive to high air temperature and drought; (iii) made up of deciduous broadleaved forests (beech and oaks), i.e., species showing growth effects also in the following year. Over the time-window 2005-2009, a significant growth decrease was vice-versa detected within the coniferous spruce forests located at medium-high elevation in the Alps. Repeated seasonal deviations in temperature and rainfall were recorded in the Alps in 2005-2009. Climate effects at local scale were examined in a site where two oak species with a different auto-ecology (sessile oak and Turkey oak) grow together. The on-going change produced heavy mortality and reduced the growth of the more demanding and less drought-tolerant sessile oak; in a few years Turkey oak became prevailing in the stand composition and structure

Litter Decomposition at Two Forest Sites in the Italian Alps: A Field Study

“…It is important to consider climatic conditions and biological activities over long-term periods, on one hand, but we also showed the importance of taking into account short-term climate effects. The analysis of climate regime in the period 2005-2009 over the alpine area and northern Italy demonstrated the repeated occurrence of seasonal deviations (such as very cold winters, warm winters, rainy winters) over the last decade (Bertini et al, 2011).…”

Recent Drought-Induced Vitality Decline of Black Pine (Pinus nigra Arn.) in South-West Hungary—Is This Drought-Resistant Species under Threat by Climate Change?

“…It could trigger a long-term decrease in forest productivity [3][4][5] or forest decline [6][7][8]. Prolonged and extreme droughts are assumed to be responsible for widespread forest mortality [9][10][11][12].…”

Sampling strategies for high quality time-series of climatic variables in forest resource assessment

“…1). This network was designed in the framework of the ICPForests monitoring program, which probably represents one of the most important sources of information for forest researchers at European level (Allegrini et al 2009 (Bertini et al 2011, Marchi et al 2017b). All the structural forest types (i.e., high forests, stored coppices, transitory crops) are well preserved mature stands in line with the ICP-Forests purpose, which is to investigate climate change and human impacts on forests.…”