Earthworms as an Ecological Indicator of Soil Recovery after Mechanized Logging Operations in Mixed Beech Forests

Abstract

Soil damage caused by logging operations conducted to obtain and maximize economic benefits has been established as having long-term effects on forest soil quality and productivity. However, a comprehensive study of the impact of logging operations on earthworms as a criterion for soil recovery has never been conducted in the Hyrcanian forests of Iran. The aim of this study was to determine the changes in soil biological properties (earthworm density and biomass) and its recovery process under the influence of traffic intensity, slope and soil depth in various intervals according to age after logging operations. Soil properties were compared among abandoned skid trails with different ages (i.e., 3, 10, 20, and 25 years) and an undisturbed area. The results showed that earthworm density and biomass in the high traffic intensity and slope class of 20–30% at the 10–20 cm depth of the soil had the lowest value compared to the other treatments. Twenty-five years after the logging operations, the earthworm density at soil depth of 0–10 and 10–20 cm was 28.4% (0.48 ind. m−2) and 38.6% (0.35 ind. m−2), which were less than those of the undisturbed area, respectively. Meanwhile, the earthworm biomass at a soil depth of 0–10 and 10–20 cm was 30.5% (2.05 mg m−2) and 40.5% (1.54 mg m−2) less than the values of the undisturbed area, respectively. The earthworm density and biomass were positively correlated with total porosity, organic carbon and nitrogen content, while negatively correlated with soil bulk density and C/N ratio. According to the results, 25 years after logging operations, the earthworm density and biomass on the skid trails were recovered, but they were significantly different with the undisturbed area. Therefore, full recovery of soil biological properties (i.e., earthworm density and biomass) takes more than 25 years. The conclusions of our study reveal that the effects of logging operations on soil properties are of great significance, and our understanding of the mechanism of soil change and recovery demand that harvesting operations be extensively and properly implemented.

Mengurangi keterbukaan hutan melalui teknik pemananenan kayu yang tepat di hutan alam

“…Pemanenan kayu juga mengganggu keseimbangan nutrisi normal di tanah hutan, mendorong nitrifikasi dan meningkatkan pencucian nutrisi sehingga membuat lapisan atas tanah menjadi miskin dan rentan terhadap erosi. Sohrabi et al (2021) menyatakan bahwa kepadatan dan biomassa cacing tanah pada intensitas lalu lintas tinggi dan kelas kemiringan 20-30% pada kedalaman 10-20 cm memiliki nilai terendah dibandingkan dengan perlakuan lainnya. Dua puluh lima tahun setelah operasi penebangan, kepadatan cacing tanah pada kedalaman tanah 0-10 dan 10-20 cm adalah 28,4% dan 38,6% lebih rendah dibandingkan dengan daerah yang tidak terganggu.…”

Evaluation of Leaf Litter Mulching and Incorporation on Skid Trails for the Recovery of Soil Physico-Chemical and Biological Properties of Mixed Broadleaved Forests

“…Land 2021, 10, 625 2 of 15 Forest soils play a pivotal role in maintaining the fertility, health, and services of the ecosystem [6] and provide nutrients, organic matter, and water [7]. In fact, soil compaction caused by heavy machinery in skidding operations dramatically reduces the balance and regulation of forest fertility by destroying the soil structure and disrupting the physical properties of the soil [8,9].…”

“…As a result, these phenomena led to a decrease in porosity [10], a reduction in the connection of pore spaces [11], and an increase in density and soil strength [12]. Soil compaction can further reduce water infiltration and gas exchange [13][14][15], with subsequent negative implications on soil macro-and microorganisms (e.g., earthworms) [6,10], penetration and elongation of root systems [16,17], and the growth of trees and seedlings [18,19]. As documented in previous studies, such impacts are generally long lasting.…”

Biomarker Responses in Earthworms Lumbricus Terrestris L. (Annelida: Lumbricidae) to Artificial Soils Contaminated with Dimethyl Phthalate

“…Among soil organisms, earthworms as bioindicators are one of the best organisms for use in soil toxicity evaluation. Their activity is strongly dependent on the quality of soil and occurrence of pollutants in it (Sohrabi et al 2021). Thus, they are included in a group of key indicators for ecotoxicological testing of industrial chemicals determined by the Organization for Economic Co-operation and Development and the European Economic Community (EEC) (Capowiez et al 2003).…”

“…Biochemical responses of organisms to environmental stress are regarded as early warning signs of pollution in the environment. The oxidative damages and the activities of certain enzymes as biomarkers in earthworms have been considered as fast and prognostic indices of individual reaction to the environmental stress (Laszczyca et al 2004;OECD, 1984;Song et al 2008;Sohrabi et al 2021). In cells, both enzymatic and non-enzymatic antioxidant defense systems are functioning against cellular oxidative damages caused by reactive oxygen species (ROS).…”