Abstract
Stable isotopes natural abundance (13C, 15N) was studied in soils from P. pinaster Ait. and P. sylvestris L. plantations located in Galicia, NW Spain, to evaluate the use of isotopic techniques for stand quality estimation. Combinations of old/young forest plantations of high/low site index, growing on acidic soils over two different parent materials (granite/schists) were studied. Significantly lower 13C in soils under P. pinaster (–27.03‰) as compared with soils under P. sylvestris (–26.13‰) were found (P < 0.001). However, soil 15N of both species did not differ significantly. Significant linear regressions between soil 13C and site index for P. pinaster were found, pointing at the 13C signature of the soil as a good stand quality indicator, especially over schists. For P. sylvestris over schists, linear regression between soil 15N and site index suggests that 15N could be used as a complementary tool in quality determinations. As a general trend for both tree species, stands with high site index showed more depleted soils in 13C and 15N as compared with low site index stands.
Highlights
The study of the processes involved in organic matter transformations of forest soils (Carballas et al, 1979, 1980, 1983; Fernández et al, 1999) and soil organic matter composition (Fernández et al, 2001; Ussiri and Johnson, 2003) has a great importance, affecting to multitude of disciplines related to silviculture and environmental sciences
The soil 13C isotopic composition of these soils was found to be substantially different under the two tree species considered
The isotopic composition of soils under P. pinaster differed from soils under P. sylvestris forests, values of d13C from P. pinaster forests soils being significantly lower than those from P. sylvestris plots
Summary
The study of the processes involved in organic matter transformations of forest soils (Carballas et al, 1979, 1980, 1983; Fernández et al, 1999) and soil organic matter composition (Fernández et al, 2001; Ussiri and Johnson, 2003) has a great importance, affecting to multitude of disciplines related to silviculture and environmental sciences. Forest soil organic matter has a great influence on the sustainability of ecosystems as well as on their soil fertility and forest productivity. Site index determinations have some limitations, since it can not be used before a minimum time of stand growth. For this reason, when early soil fertility estimation is requited, several authors use changes on soil organic matter content and dynamics to quantify the success of a sustainable silviculture (Morris et al, 1997). The study of soil organic matter characteristics should be a priority research line for the knowledge of the present and future status of nutrient cycles in forest ecosystems (Nilsson et al, 1995; Sánchez et al, 1997; Fernández et al, 1999)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
