Abstract
The removal of the litter layer in Portuguese pine forests would reduce fire hazard, but on the other hand this practice would influence the thermal regime of the soil, hence affecting soil biological activity, litter decomposition and nutrient dynamics. Temperature profiles of a sandy soil (Haplic Podzol) under a pine forest were measured with thermocouples at depths to 16 cm, with and without litter layer. The litter layer acted as a thermal insulator, reducing the amplitude of the periodic temperature variation in the mineral soil underneath and increasing damping depths, particularly at low soil water contents. At the mineral soil surface the reduction of amplitudes was about 2.5 ºC in the annual cycle and 5 to 6.7 ºC in the daily cycle, depending on the soil water content. When soil was both cold and wet, mean daily soil temperatures were higher (about 1 - 1.5 ºC) under the litter layer. Improved soil thermal conditions under the litter layer recommend its retention as a forest management practice to follow in general.
Highlights
About 30 % (900 x 103 ha) of the total forest area in Portugal is covered by Pinus spp., growing mainly on nutrient-poor sandy soils under Mediterranean climate
The removal of the litter layer and understory vegetation is being recommended in the country, in spite of the awareness that litter removal can be responsible for the yield decline in several forest species, such as Picea sitchensis (Proe et al, 1994) and Eucalyptus globulus (Jones et al, 1999)
The presence of litter is important for the sustainability of pine forests, due to better nutrient dynamics (Meentemeyer & Berg, 1986) and water balance (Cubera et al, 2004) in soils with a very limited potential
Summary
About 30 % (900 x 103 ha) of the total forest area in Portugal is covered by Pinus spp., growing mainly on nutrient-poor sandy soils under Mediterranean climate. Forest fires have become a severe economic and environmental concern in Portugal over the last years. An average of about 74 x 103 ha of forest was devastated by fires every year (DGRF, 2005). Retention or removal of the litter layer from the forest floor raises several issues. The presence of litter is important for the sustainability of pine forests, due to better nutrient dynamics (Meentemeyer & Berg, 1986) and water balance (Cubera et al, 2004) in soils with a very limited potential. The litter layer is assumed to influence the thermal regime of the mineral soil underneath
Sign-in/Register to view highlights & summary 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.
