Tree biomass and deadwood density into ageing Turkey oak coppices in Tuscany

Abstract

Recent data from the National Forest Inventory point out the further reinforcement of coppice area under the position of “mature” standing crop or post-cultivation phase, both of them being spread throughout the original cultivation area. Such condition, mainly due to the less profitable fuel wood harvesting, involves also a share of the more productive types, i.e., Turkey oak forests. Here, a diffuse but forced approach among managers is to “wait and see”. The pro-active way of coppice conversion into high forest is otherwise being practiced in the public domain but on much smaller areas. Against management dilemmas, ageing stands growing under medium to good site conditions show a dynamic growth pattern resulting in a high age-related wood matter storage. At the same time, the heavy and prolonged regular mortality occurring in the fully-stocked shoot population builds up high amounts of deadwood, this becoming an attribute of these newly-formed types. Carbon storage is therefore coming to be one of the major tasks attributable to these systems within the post-cultivation phase. Aims of the work are to estimate both densities of living woody mass and standing+lying deadwood without any lower survey limit, given the small-sized stems building up these types; to check deadwood types/living biomass ratios; to survey deadwood decay; to analyse the dynamics of mass storage within the stands. Three case-studies, aged about three times the traditional rotation and different as for location and site-index, were selected at the purpose. Living woody mass density plus standing and lying deadwood per decay class were determined. Living woody mass density, made basically by stem+thick branches (95%), varies within 160 and 310 Mg ha-1. Total deadwood amount ranges from 22 to 30 Mg ha-1, i.e., 9 to 14% of living woody biomass. The lying/standing deadwood ratio is being reversed with ageing from 1/2 to 2/1-3/1. The intermediate decay class is prevailing (60-85%) across the sites. The observed dynamics and the age-related figures as well, suggest the role these types may play in soil conservation, forest recovery and carbon storage. The need of a consistent monitoring of the further post-cultivation progress is stressed to recognize the driving forces acting, the onset of possible limiting factors and feedbacks

Structural and dendroecological analysis of Quercus petraea subsp. austrothyrrenica Brullo, Guarino & Siracusa in the Madonie Natural Park (Sicily)

“…Nel complesso, la necromassa in piedi è maggiore di quella a terra. Il valore della necromassa totale è inferiore rispetto a quello rilevato nei popolamenti di querce (Quercus robur e Q .petraea) nel sud della Svezia (15.7 m 3 ha -1 - Nordén et al, 2004), nelle fustaie pluristratificate di cerro del Molise (12.8 m 3 ha -1 Marchetti et al, 2006), nei boschi di farnetto della Calabria (5.3 m 3 ha -1 Barreca et al, 2008), nei boschi di cerro sia gestiti (4.5 m 3 ha -1 ) che non gestiti (31.6 m 3 ha -1 ) del Molise (Lombardi et al, 2008), nei cedui di cerro invecchiati dell'Italia centrale (21.8-40.3 m 3 ha -1 Bertini et al, 2010). Per quanto riguarda le classi di decomposizione del legno morto prevalgono quelle delle fasi iniziali (2-4) ad eccezione delle aree 1 e 2 dove si hanno quelle tipiche delle fasi più avanzate della decomposizione (Fig.…”

Structure and Dynamics of Deadwood in Pine and Oak Stands and their Role in CO2 Sequestration in Lowland Forests of Central Italy

“…In this Mediterranean area, the possibility of a continuous accumulation of deadwood over time is usually a result of the natural disturbance and the abandonment of the timber harvest [7,[46][47][48][49][50][51] or, better, of the choice to carry out minimal interventions since the removal of deadwood has been one of the most frequent operations in forest, favoured by the rights of use of local populations for the collection of deadwood as firewood [15,24,25] and the fear of forest fires by managers. Deadwood is mainly caused by tree mortality and the accumulation is due to the production coupled with the degradation and decay of biological agents [6,[52][53][54].…”

“…RDT progressively increase as time elapses from management abandonment. Downed deadwood turns prevalent in other mesic oak stands [47,51,52].…”

C and N concentrations in different compartments of outgrown oak coppice forests under different site conditions in Central Italy

“…This type well depicts the dynamics of management established over the last decades. According to the National Forest Inventory (NFI 1988), the 41 % of cover was aged more than 20, that is, more than the customary rotation (12-14 years). Twenty years later (NFI 2006), 93 % (58 plus 35 %) of Turkey oak coppice forest was classified as mature (i.e., reaching the age of rotation) and outgrown (i.e., aged two to three times or more) at national level, the same share reached 98 % (45 plus 53 %) in Tuscany (Bertini et al 2010).…”