Hydrology-oriented (adaptive) silviculture in a semiarid pine plantation: How much can be modified the water cycle through forest management?

Abstract

Campo García, ADD.; Gualberto Fernandes, TJ.; Molina Herrera, A. (2014). Hydrologyoriented (adaptive) silviculture in a semiarid pine plantation: How much can be modified the water cycle through forest management?. European Journal of Forest Research. 133(55):879-894. doi:10.1007//s10342-014-0805-7. European Journal of Forest ResearchHydrology-oriented (adaptive) silviculture in a semiarid pine plantation: how much can be modified the water cycle through forest management?--Manuscript Draft-- Order of Authors Secondary Information:Abstract: Hydrology-oriented silviculture might adapt Mediterranean forests to climatic changes, although its implementation demands a better understanding and quantification on the water fluxes. The influence of thinning intensity (high, medium, low and a control) and its effect on the mid-term (thinned plots in 1998 and 2008) on the water cycle (transpiration, soil water and interception) and growth (Basal Area Increment, BAI) were investigated in 55-year-old Aleppo pine trees. Thinning enhanced a lower dependence of growth on climate fluctuations. The high intensity treatment showed significant increases in the mean annual BAI (from 4.1 to 17.3 cm2) that were maintained in the mid-term. Thinning intensity progressively increased the sap flow velocity (vs) in all cases with respect the control. In the mid-term, an increased functionality of the inner sapwood was also observed. Mean daily tree water use ranged from 5 (control) to 18 (high intensity) l tree-1. However, when expressed on an area basis, daily transpiration ranged from 0.18 (medium) to 0.30 mm (control), meaning that, in spite of the higher transpiration rates in the remaining trees, stand transpiration was reduced with thinning. Deep infiltration of water was also enhanced with thinning (about 30% of rainfall) and did no compete with transpiration, as both presented opposite seasonal patterns. The changes in the stand water relationships after ten years were well explained by the forest cover metric. The blue to green water ratio changed from 0.15 in the control to 0.72 in the high intensity treatment, with the remaining treatments in the 0. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 velocity (v s ) in all cases with respect the control. In the mid-term, an increased functionality of the inner sapwood was also observed. Mean daily tree water use ranged from 5 (control) to 18 (high intensity) l tree -1 . However, when expressed on an area basis, daily transpiration ranged from 0.18 (medium) to 0.30 mm (control), meaning that, in spite of the higher transpiration rates in the remaining trees, stand transpiration was reduced with thinning. Deep infiltration of water was also enhanced with thinning (about 30% of rainfall) and did no compete with transpiration, as both presented opposite seasonal patterns. The changes ...

Contrasting growth and water use efficiency after thinning in mixed Abies pinsapo-Pinus pinaster-Pinus sylvestris forests

“…The BAI obtained in year 9 after thinning was highest in the heavily thinned plots, where many dominated and small-sized trees were removed. This is in line with other results obtained for Mediterranean pine stands, which have shown the positive effect of thinning on growth Del Campo et al 2014). In contrast, Scots pine showed that light thinning intensity resulted in a statistically significant higher BAI.…”

“…Thinning studies have shown that the availability of resources is relatively higher in thinned stands than in unthinned plots (Del Campo et al 2014;Gebhardt et al 2014). In addition to decreased competition for light, water and nutrients, the presence of logging residues may increase the amount of nutrients available for strong growth increase and change the leaf area index (LAI) as a result of silvicultural treatments (De las Heras et al 2012).…”

“…Water is the most limited resource for mixed fir-pine stands in southern Spain, and is predicted to become even scarcer in coming years. To overcome this problem, forest managers use thinning (of different intensity) to reduce tree competition for water within stands (Martín-Benito et al 2011;Del Campo et al 2014). When properly used, thinning reduces long-term stress by competition, but it also reduces the vulnerability of trees to extreme drought events Sánchez-Salguero et al 2012).…”

Water-oriented management in forest plantations: combining hydrology, dendrochronology and ecophysiology

“…Maestre et al, (2003) report that the interception value usually is up to 50% of the annual rainfall amount, and that rain events smaller than 10 mm are completely or almost completely intercepted. However, Yaseef et al, (2010) found 11% interception in an Aleppo pine plantation, while Del Campo et al (2014) in an experimental thinning in Aleppo pine, found values between 12.4 and 39.6%, the latter value corresponding to the control plot.…”

“…This author affirms that Spanish forests evapotranspire 39% of the annual incoming rainfall, although during droughts this ratio can rise up to 42% and that these results provide evidence of the importance of placing forest and land management at the core of hydrological planning, especially in the context of climate change. Studying the effects of forest management on the water cycle should, thus, become a priority for policy makers because adaptive forest management policies in Mediterranean ecosystems should have a strong hydrological foundation (Planinsek et al, 2010;Del Campo et al, 2014).…”