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Silvicultural and logging impact on soil microarthropod community in Mediterranean coppice.
No full textCoarse woody debris variability due to human accessibility to forest
Full text linkOriginally published in Forests (MDPI):
Behjou FK, Lo Monaco A*, Tavankar F, Venanzi R, Nikooy M, Picchio R (2018) Coarse woody debris variability as result of human accessibility to forest. Forests 9(9): article number 509 (open access)
Corresponding author: Angela Lo Monaco, [email protected]
DOI: 10.3390/f9090509
The article can be dowloaded at: https://www.mdpi.com/1999-4907/9/9/509
Abstract: Coarse woody debris (CWD) plays an important role in supporting biodiversity and
assisting ecological processes. Sometimes local people intervene modifying the expected distribution
of CWD components, harvested as fuel wood. The effect of the human accessibility (HA) on the
volume and characteristics of CWD (snag, downed log and stump) was investigated in the natural
uneven-age mixed hardwood stands of the Hyrcanian forests of Iran to quantify the impact on CWD.
The HA was classified into three classes (easy, medium and difficult) on the basis of slope class,
slope direction to the nearest road and road type. As expected, a negative relationship between
the degree of accessibility was found with respect to the main qualitative and quantitative indices
referring to CWD. The results showed that the volume of CWD decreased with an increase in
human accessibility class (HAC), thus the mean volume of CWD in the difficult, medium and easy
accessibility classes were 14.87 m3 ha1, 8.84 m3 ha1 and 4.03 m3 ha1, respectively. The decrease in
CWD volume was more associated with the decreasing volume of small diameter of low decayed
downed logs. The ratio of snag volume to standing volume, the ratio of downed log volume to the
volume of trees and the ratio of CWD volume to standing volume increased with a decrease in HAC,
while the ratio of downed log volume to snag volume decreased with a decrease in HAC. No selective
behaviour on the botanical species of CWD was recorded. For ecological forest management, the effect
of HAC on CWD should be considered. A constant supply of snags and downed logs must be
preserved to assure a high level of biodiversity. To balance social needs and biodiversity requirements,
an increased level of CWD retention might be needed in areas with easy accessibility. The obtained
results may be useful when ecological and socio-economical needs have to be taken into consideration
in future policy-making decisions.
Keywords: snag; downed log; stump; forest road; uneven-agemixed hardwood stands; Hyrcanian forest
Soil and forest regeneration after different extraction methods in coppice forests
Full text linkCoppice is considered the oldest form of sustainable forest management in the Mediterranean area. Generally, it produces rapidly woody biomass and environmental benefits. This research was implemented through an experimental design based on two steps: analyzing the impact of silvicultural treatment (coppice with standards) and logging on forest soil and tree regeneration. It included the soil and regeneration recovery capacity of forests managed as coppice related to different logging systems and treatments applied over a six-year period. The findings demonstrated that tree species regeneration composition was not affected by silvicultural treatment and only slightly by harvesting system. Instead, the physical, chemical and biological soil features were only marginally affected by the silvicultural treatment applied, but strongly impacted by harvesting operations, with clear differences between the systems. The least damaging harvesting system was TLS (Tree Length System) followed by FTS (Full Tree System) and SWS (Short Wood System) that showed a more intense impact. This trend started only six months after harvesting and continued for more than 36 months post-harvesting in a lesser dynamic. The recovery of coppicing was almost complete 36 months after harvesting, without substantial differences between logging systems. Recovery from logging showed a clear positive trend, but 52 months after harvesting only the TLS area had completely recovered. For FTS and SWS, recovery occurred but was very weak
Post-harvest evaluation of soil physical properties and natural regeneration growth in steep-slope terrains
Full text linkProtection of forest soils during harvesting operations is necessary to reduce damage and accelerate recovery time. The current study aims to evaluate soil physical properties, natural regeneration, and its recovery process in treatments including slope gradient, traffic intensity and skid trail after long periods of time, after ceasing the timber harvesting operations. The most recent skidding operations within each 5 years recovery period were studied for a chronosequence of 20 years. Soil samples were taken in abandoned skid trails and data were recorded on naturally regenerated species and density. The results revealed that most soil disturbances occurred on the slopes > 20%, as well as the highest levels of traffic intensity. Bulk density and penetration resistance were still higher than the control area, with a significant difference between them, while total porosity was partially recovered. Twenty years after the skidding operation, soil bulk density and penetration resistance were 13.2% and 23.7% higher than the control area, while total porosity was 9.78% lower the than value of the control area. Seedlings of 50-150 cm and > 150 cm in height on skid trails had significantly lower density than those in the control. The number of seedlings per m2 was less than the control area in all skid trails and for all height classes. The proportion of seedlings present in low traffic intensity was higher than in medium and high traffic intensities. The findings confirmed that full recovery rates are lengthy, and more time than 20 years is required to fully recover, especially with regards to penetration resistance
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Soil disturbance induced by silvicultural treatment in chestnut (Castanea sativa mill.) coppice and post-disturbance recovery
Full text linkChestnut forests represent an important environmental and landscape element in Europe, especially in the hill regions of southern Europe. In Italy, the total surface amount of chestnut forests is slightly expanded with 788,408 hectares, but orchards show a dramatic reduction (147,586 hectares or 20% of the total) and timber-producing stands a comparable expansion (605,888 hectares or 80%). The coppice management actually applied is considered one of the oldest forms of sustainable forest management. Over the years, coppice highlighted its versatility, resilience and multifunctionality. In this management system, in consideration of the “frequent” cutting cycles, special attention must be paid to forestry operations, because tree damage and soil compaction can trigger fungal disease and soil erosion. Frequent and repeated machine traffic increases the risk for soil degradation derived from compaction, topsoil removal and general disturbance. This study covered different forest areas and mechanization levels, in order to evaluate if the extent, type and severity of soil disturbance changed with site characteristics and logging technique. Furthermore, the study sought to obtain a better knowledge about the recovery time required for restoring the original soil properties after a disturbance has occurred. The findings showed that physical, chemical, and biological soil features were only partially disturbed by the coppicing and again that a high level of specialized mechanization does not generate heavier soil impact compared with the smaller and lighter machines deployed under the traditional and intermediate mechanization scenarios. Soil recovery in the impacted areas is already measurable one year after harvest and may be complete within the eight year—that is halfway through the standard rotation applied in the region to chestnut coppice
Soil Disturbance and Recovery after Coppicing a Mediterranean Oak Stand: The Effects of Silviculture and Technology
Full text linkTraditional coppice management system is one of the most debated topics in the Mediterranean area, as it is a forest management system that accounts for over 23 million hectares. Coppicing is considered the oldest form of sustainable forest management. Its past and current widespread popularity is mainly due to its capacity to positively contribute to the rural economy and ecosystem services. This research aimed at assessing the effect of coppicing on soil characteristics, understanding a possible treatment return time, and evaluating the implementation of proper sustainable forest operations (SFOs) in order to have a better understanding of the disturbance caused by silvicultural treatment and forest operations with two different harvesting techniques. The results demonstrated that physical, chemical, and biological soil features were partially disturbed by the coppicing. Both silvicultural treatment and forest operations influenced soil disturbance. The least impactful technique was extraction by winch, while forwarding resulted in heavier alterations of soil characteristics. It took about five years for the soil to recover its original pre-harvest conditions when the disturbance was caused by the silvicultural treatment alone (non-trafficked areas) and about eight to nine years when the disturbance was the cumulated effect of silvicultural treatment and logging activity (trafficked areas)
Sustainability assessment of alternative strip clear cutting operations for wood chip production in renaturalization management of pine stands
Full text linkIn Mediterranean regions, afforested areas were planted to ensure the permanence of land cover, and to protect against erosion and to initiate the vegetation processes. For those purposes, pine species were mainly used; however, many of these stands, without silvicultural treatments for over fifty-sixty years, were in a poor state from physical and biological perspective, and therefore, clear-cutting on strips was conducted as silvicultural operation with the aim to eliminate 50% of the pine trees and to favor the affirmation of indigenous broadleaves seedlings. At the same time, the high and increasing demand of the forest based sector for wood biomass related to energy production, needs to be supplied. In a modern and multifunctional forestry, in which society is asking for sustainable forestry and naturalistic forest management, forestry operations should ideally be carried out in a sustainable manner, thus support the concept of sustainable forest management. All these aspects are also related to the innovation in forestry sector for an effective energetic sustainability. Three different forest wood chains were applied in pine plantations, all differing in the extraction system (animal, forestry-fitted farm tractor with winch, and double drum cable yarder). The method of the sustainability impact assessment was used in order to assess potential impacts of these alternative management options, and a set of 12 indicators covering economic, environmental, and social dimensions was analyzed. Further, to support decision makers in taking informed decisions, multi-criteria decision analysis was conducted. Decision makers gave weight towards the indicators natural tree regeneration and soil biological quality to support the achievement of the forest management goal. Results showed that first ranked alternative was case 2, in which extraction was conducted by a tractor with a winch. The main reason for that lies in the fact that this alternative had best performance for 80% of the analyzed criteria
Gestione forestale sostenibile in boschi misti alpini- il caso della foresta di Tarvisio (UD)
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