The two NETs plots commenced operations effectively from 4 November 2022, continuing until 14 December 2023, spanning approximately 13 months. To ensure a meaningful comparison between the two plots and to accurately convert the erosion results into square meters and hectares, we initially determined their respective areas and slopes. Plot P1 (SSM) exhibited a mean slope of 47.1% and covered an area of 373 m2, while Plot P2 (BSM) featured a mean slope of 49.03% and occupied an area of 435 m2. The combined average slope for both plots was calculated at 48.17%. As for leaf collection, we conducted multiple weightings throughout the year, whereas sediment weight measurements were undertaken only three times during the entire year.
Leaf Collection
After the initial leaf collection, a notable disparity became evident between the two plots. Plot P1, managed using the SSM, amassed a greater quantity of leaves compared with Plot P2, where the BSM was applied. Plot P1 accumulated a total leaf weight of 6.4 kg, whereas Plot P2 amassed 3.8 kg.
These findings, however, did not factor into the variation in slope between the two plots. To address this, we adjusted the results proportionally, considering the slope. Consequently, the weighted leaf mass of Plot P1 experienced a slight increase, rising from 6.4 kg to 6.6 kg, while Plot P2 saw a decrease, dropping from 3.8 kg to 3.7 kg. Subsequently, we divided the adjusted sum by the respective plot areas, revealing soil loss rates of 0.018 kg/m
2 for Plot P1 (SSM) and 0.008 kg/m
2 for Plot P2 (BSM). Notably, the BSM exhibited a 55.5% reduction in leaf loss compared to the SSM (
Table 4).
After the first process of weighing, we investigated the rainfall that generated the leaf loss. Thanks to the data provided by the rain gauge of the Abruzzo Hydrological Centre (Centro Funzionale e Ufficio Idrologia, Idrografico, Mareografico–Agenzia di Protezione Civile della Regione Abruzzo), we could correlate the leaf loss inside the two plots with the rainfall that generated that loss. As evident, there exists a substantial correlation among rainfall, seasonal variations, and leaf loss. Particularly, during November and December, an important leaf loss is observed, closely associated with both rainfall and the seasonal shedding typical of broadleaf forests. Despite potentially lower rainfall levels during this period compared with others, the majority of leaf shedding occurs, as exemplified by the January collection, which yielded more leaves than that of 16 February. This trend persists throughout the year, with consistent leaf loss occurring even during periods of relatively lower total rainfall. Consequently, there is a continual loss of organic matter throughout the year, emphasizing the ongoing impact of leaf shedding on forest ecosystems (
Table 5 and
Figure 6).
Table 5 and
Figure 6 clearly show that Plot P2 experienced a decrease in the loss of leaves, suggesting that this plot has a blocking effect on leaves, so it could reduce the organic matter loss.
Regarding the sediment collected by the two erosion plots, we faced limitations in conducting the same procedure as that used for the leaves. We could only conduct three weightings throughout the year, allowing us to establish correlations with rainfall and seasonal variations. Recognizing the significance of differentiating sediment types—rock fragments, which, depending on their size, can pose risks to human health, and fine sediment, which affects only soil fertility—we initially categorized the collected sediment into gravel (with a diameter larger than 2 mm) and fine sediment (including sand, loam, and clay).
The results of this differentiation revealed that in Plot P1 (SSM), we collected 4508.1 g of gravel and 3698.4 g of fine sediment, while in Plot P2 (BSM), we collected 3486.2 g of gravel and 5039 g of fine sediment. Similar to the leaves, we adjusted the collected sediment weights based on slope and area to obtain values in kg/ha.
For Plot P1 (SSM), erosion rates were calculated at 123.5 kg/ha for gravel and 101.3 kg/ha for fine sediment, totalling 224.8 kg/ha. In Plot P2 (BSM), the erosion rates were 78.8 kg/ha for gravel and 113.9 kg/ha for fine sediment, with a total erosion of 192.6 kg/ha. Notably, the BSM exhibited lower erosion rates overall, with a 19% decrease in total soil erosion. While gravel erosion consistently favoured Plot P1, fine sediment erosion initially favoured Plot P2, though this trend equalized over the year.
The final weighing showed a decrease in fine sediment erosion in Plot P2, attributed to its enhanced anti-erosive capacity one year post-logging, suggesting better forest recovery and subsequent erosion mitigation. The results show promising differences. For a better comprehension of the results,
Table 5 shows the Plot P1 and Plot P2 results.
Apart from mitigating leaf and soil losses, the BSM demonstrated effectiveness in averting large rock displacement. While Plot P1 experienced no obstructions from rocks, Plot P2 intercepted numerous rocks successfully.
By integrating standards with bundled twigs, the method effectively prevented the movement of six rocks, collectively weighing 90.35 kg. Notably, these blocked rocks encompassed varying weights, including heavy ones, underscoring the method’s pivotal role in ensuring human safety.
The results underscore the method’s ability to address broader concerns beyond soil erosion. By obstructing rocks, the BSM mitigates potential hazards and preserves environmental integrity, demonstrating its versatility across diverse terrains. Its successful application in Plot P2 highlights its adaptability to challenging conditions, validating its efficacy in sustainable land management.
Continued research and implementation of the BSM offer promise in mitigating soil erosion and enhancing environmental resilience. Integrating findings from this study into land management practices can inform the development of more robust erosion control strategies, ensuring the long-term health and sustainability of ecosystems globally.
The ability of the BSM to effectively block rocks complements its other benefits, making it a comprehensive solution for mitigating various forms of land degradation and promoting ecosystem health.
After converting all measurements to tons per hectare (t/ha), we conducted a comprehensive analysis of sediment accumulation in the two plots, P1 and P2, as shown in
Table 6.
The sediment amassed in P1 totalled 0.40 t/ha, while P2 accumulated 0.28 t/ha. This calculation revealed a noteworthy 30.72% reduction in erosion for P2 compared with P1, indicating a potentially more effective erosion control strategy in the latter. Additionally, we assessed the impact of rock barriers installed in the area.
The weight of rocks obstructed by these barriers was quantified at 2.07 t/ha. Had the barriers not been in place, the erosion rate in P2 would have surged to 2.35 t/ha. This figure is staggering, representing a 487.5% increase over P1’s erosion rate and a 739.3% increase over the actual erosion rate in P2. The results indicate that there are encouraging differences.
The comparison between P1 and P2 highlights the effectiveness of such treatments, emphasizing the importance of implementing sustainable land management practices to combat erosion effectively.
This study not only provides valuable insights into erosion dynamics but also emphasizes the need for proactive measures to address soil erosion. Further research and implementation of erosion control strategies are warranted to mitigate the adverse effects of erosion on land and ecosystems worldwide.
From our experience, we can infer that within coppice forests in sloping areas, especially where there is a significant risk to human health (such as the presence of large rocky boulders), it might be prudent to employ our silvicultural model, known as the BSM. The data collected during the initial year of experimentation is preliminary and requires further verification over subsequent seasons, as there are no existing experimental data in the literature for comparison.
Regarding the considered silvicultural aspects, the preliminary results confirm the effectiveness of the BSM as a treatment to mitigate surface soil erosion risk. Our model successfully reduces erosion, particularly concerning large sediment, and prevents the loss of leaves and organic matter. These positive outcomes are attributed to the action of the bands of standards and the bundles of twigs, which act as effective barriers. Additionally, the BSM does not compromise wood production or forest owner profits while simultaneously improving ecological efficiency. Notably, there are no reported technical inconveniences for forest users, and the access methods and extraction procedures remain straightforward.
Regarding leaf loss, the BSM-treated plot shows a great reduction (55%) in litter removal. This finding underscores the influence of coppice management on gradual soil fertility decline. Because of frequent rotations compared with high forest management, the system lacks sufficient time for organic matter mineralization. Moreover, on sloping terrain, a substantial portion of litter is lost to water erosion.
The NET (Natural Erosion Plot), although still a prototype, demonstrates usefulness and effectiveness. It effectively captures sediment of all types, even in the challenging context of a coppice forest with an average slope of 48%. Its applicability extends to various environments, and with modifications, it could potentially provide run-off data in addition to its existing capabilities.