HARVESTER PRODUCTIVITY AND COSTS IN CLEAR CUTTING Pinus taeda STANDS UNDER DIFFERENT MANAGEMENT REGIMES

The increased demand for several forest products makes it necessary to apply different management regimes in forest stands, which may influence the wood harvesting operations. This study aimed to evaluate the effect of average individual tree volumes obtained through different management regimes on harvester productivity and costs, thereby enabling to generate information for forest managers. The study was carried out in three Pinus taeda L. stands under clear cutting with different average individual tree volumes (AIV): I (0.367 m3); II (0.582 m3); and III (0.766 m3). Working cycle times, productivity per productive machine hour, energy yield and production costs were obtained by a time and motion study, in which the average values obtained were compared by the Tukey-Kramer test (α ≤ 0.05). The work elements of the harvester’s work cycles were affected by forest management regimes, mainly the movement and the processing, with significant statistical difference between stands, but no difference between total working cycle times. The management regime applied to forest stands influenced the spacing and whole trunk volume which consequently increased the average productivity of the machine from 36.8 to 74.1 m³ per productive machine hour in treatments I and III, respectively, and reduced production costs by 50%. The forest management regimes influenced the clear-cutting operation with harvester.

Soil quality and C-S-R fungal communities in monoculture plantations after conversion from subtropical forest

Intensive clear cutting of natural forests and conversion to monoculture plantations are ongoing worldwide, leading to degradation of soil quality and microbial functions. Here, we compared soil quality index (SQI) and fungal community in a natural forest (Forest) and four 5-year-old monoculture plantations, including Camellia oleifera (Oil), Amygdalus persica (Peach), Myrica rubra (Berry) and Cunninghamia lanceolata (Fir), in a subtropical region of China. After conversion, soil pH rose up to 0.31, but organic carbon, total nitrogen, sucrase, acid protease, glutaminase and phosphatase activities decreased by 83%, 59%, 43%, 31%, 64%, 66% and 77%, respectively, in the plantations. Correspondingly, the SQI dropped by 65%. High-throughput sequencing of the ITS1 region demonstrated an increase in α-diversity and a striking difference in β-diversity following conversion. Changes in the dominant fungal taxa following forest conversion to plantations was interpreted by Grime’s C-S-R life history framework. Conversion increased the fungal groups with stress-tolerant (S) and ruderal (R) strategies - mainly copiotrophic saprophytes, such as Ascomycota and Zygomycota, but decreased the fungal groups with competitor (C) strategies - mainly oligotrophic saprophytes and mycorrhizal fungi, such as Basidiomycota. Genera affiliated to those phyla including Pseudophialophora, Rhytisma increased, but Russula decreased. Redundancy analysis and structural equation modeling indicated that the diversity and composition of fungal communities changed with soil quality degradation, which were mainly driven by increased soil pH, decreased available carbon and nutrients (N, P), and related enzymes activities.

Pine Forest Management and Disturbance in Northern Poland: Combining High-Resolution 100-Year-Old Paleoecological and Remote Sensing Data

Global warming has compelled to strengthen the resilience of European forests. Due to repeated droughts and heatwaves, weakened trees become vulnerable to insect outbreaks, pathogen invasions, and strong winds. This study combines high-resolution analysis of a 100-year-old high-resolution peat archive synthesized from the Martwe peatland in Poland with remote sensing data. We present the first REVEALS based vegetation reconstruction in a tornado-hit area from Poland on the background of previous forest management in monocultural even-aged stands – Tuchola Pinewoods. During the 20th century, the pine monocultures surrounding the peatland were affected by clear-cutting and insect outbreaks. In 2012, a tornado, destroyed ca. 550 ha of pine forest around the peatland. The palynological record reflects these major events of the past 100 years as well as changes in forest practices. Our study showed the strong relationships between the decrease of Pinus sylvestris (Scots pine) in palynological record as well as planting patterns after the tornado. Moreover, past forestry practices [such as domination of Pinus sylvestris, the collapse of Picea abies (Norway spruce), low share of Betula spec. (birch) due to Pinus sylvestris promotion and probable also to a lesser by removal of Betula as a “forest weed,” and low plant coverage of tree species due to clear-cutting and cutting after insect outbreaks] were well identified in the proxy record. In monocultures managed over decades, the reconstruction of vegetation may be challenging due to changes in the age composition of the Pinus sylvestris stands. We found that through historical, remote sensing, and paleoecological data, the dynamics of disturbances such as insect outbreaks and tornadoes, as well as the changing perceptions of local society about forests, can be determined.

Occupancy of wild southern pig-tailed macaques in intact and degraded forests in Peninsular Malaysia

Deforestation is a major threat to terrestrial tropical ecosystems, particularly in Southeast Asia where human activities have dramatic consequences for the survival of many species. However, responses of species to anthropogenic impact are highly variable. In order to establish effective conservation strategies, it is critical to determine a species’ ability to persist in degraded habitats. Here, we used camera trapping data to provide the first insights into the temporal and spatial distribution of southern pig-tailed macaques (Macaca nemestrina, listed as ‘Vulnerable’ by the IUCN) across intact and degraded forest habitats in Peninsular Malaysia, with a particular focus on the effects of clear-cutting and selective logging on macaque occupancy. Specifically, we found a 10% decline in macaque site occupancy in the highly degraded Pasoh Forest Reserve from 2013 to 2017. This may be strongly linked to the macaques’ sensitivity to intensive disturbance through clear-cutting, which significantly increased the probability that M. nemestrina became locally extinct at a previously occupied site. However, we found no clear relationship between moderate disturbance, i.e., selective logging, and the macaques’ local extinction probability or site occupancy in the Pasoh Forest Reserve and Belum-Temengor Forest Complex. Further, an identical age and sex structure of macaques in selectively logged and completely undisturbed habitat types within the Belum-Temengor Forest Complex indicated that the macaques did not show increased mortality or declining birth rates when exposed to selective logging. Overall, this suggests that low to moderately disturbed forests may still constitute valuable habitats that support viable populations of M. nemestrina, and thus need to be protected against further degradation. Our results emphasize the significance of population monitoring through camera trapping for understanding the ability of threatened species to cope with anthropogenic disturbance. This can inform species management plans and facilitate the development of effective conservation measures to protect biodiversity.

Natural Regeneration of the Tree Stand in the Bilberry Spruce Forest—Clear-Cutting Ecotone Complex in the First Post-Logging Decade

Bilberry spruce forests are the most widespread forest type in the European boreal zone. Limiting the clear-cuttings size leads to fragmentation of forest cover and the appearance of large areas of ecotone complexes, composed of forest (F), a transition from forest to the cut-over site under tree canopy (FE), a transition from forest to the cut-over site beyond tree canopy (CE), and the actual clear-cut site (C). Natural regeneration of woody species (spruce, birch, rowan) in the bilberry spruce stand—clear-cut ecotone complex was studied during the first decade after logging. The effects produced by the time since cutting, forest edge aspect, and the ground cover on the emergence and growth of trees and shrubs under forest canopy and openly in the clear-cut were investigated. Estimating the amount and size of different species in the regeneration showed FE and CE width to be 8 m—roughly half the height of first-story trees. Typical forest conditions (F) feature a relatively small amount of regenerating spruce and birch. The most favorable conditions for natural regeneration of spruce in the clear-cut—mature bilberry spruce stand ecotone are at the forest edge in areas of transition both towards the forest and towards the clear-cut (FE and CE). Clear-cut areas farther from the forest edge (C) offer an advantage to regenerating birch, which grows densely and actively in this area.

Deadly Landslide and Debris Avalanche in Abikar Village, Farsan City, Chaharmahal and Bakhtiari Province, Iran.

On the evening of April 1, 1998, near Farsan city, Chaharmahal and Bakhtiari province, Iran, along the Labad river, the southern edge of the valley of Mt. Kino slid down into the Labad river and buried Abikar village under several meters of debris on the opposite flank of the river valley. The overall casualties and damages claimed the life of 54 people (20 men, 30 women, and 4 infants), the death of 1300 livestock, and the destruction of 40 hectares of farmlands and orchards. The observation of several pieces of extraordinary evidence in the landslide area, such as the lack of a landslide dam or barrier across the river after the slope sliding, evidence of high velocity debris flow, the transformation of some debris material by jumping into the far end of debris flow, and the effects of a severe storm in front of debris flow mass, have made this phenomenon a concerning complex landslide event for further research. The causes for long debris-flow run out have been discussed in some works. Most of these studies have pointed out the effect of air cushion formation under the debris collapsed into the river valley that facilitates the long-distance transport of detrital flows. Another rare mechanism for interpreting the long-distance travel of rock boulders is blocks and boulders displacement in the form of jumping, which might be due to the energy from collisions between heavy rocks and the hard bottom of the river, breaking them down into smaller pieces and making them jump into the far distant points. Field evidence observed in Abikar landslide indicates that the occurrence of this landslide and the consequent events were a combination of these two mechanisms. Part of the debris has moved in a rapid flow, and the other part has jumped to the opposite flank of the river over the debris flow.The deadly landslide in Abikar followed an exceptional rainfall that reached 190 mm during a week prior to the landslide event. In this event, the southern flank of the Labad river valley that composed of limestone, shale, and marlstone layers with a slope angle of 75 degrees and the highest point of 1200 m from the bottom of the river, fell down into the valley and mounted the opposite bank of the river with the deposit height exceeding 100 m. Some observed evidence of the field study showed that the toe erosion by the river as well as intensive rainfall could be the main triggering factor for this landslide. After the fall of southern block (1200 m height, 600m width and average thickness of 30 m), most detrital material moved toward the opposite flank by following the ground surface with a high shear force that cut buildings, gardens, and other people properties to the depth of approximately 6 m. Observing a transported walnut tree with the root and trunks at the end part of the debris confirms the high shearing energy of the debris. The uprooting of shrubs and clear-cutting of the entire vegetation cover to the distance of 100-200 m in a vast area in front of the moving debris flow confirmed the generation of a severe typhoon in front of the debris as well as the generation of high-pressure air cushion under the debris. Another interesting observed evidence confirming the movement of some material by jumping is the presence of large masses of source rock on the top of the deposit and at the end of the debris without any sign of mud contamination of the debris matrix.