DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu



ŠUMARSKI LIST 9-10/2022 str. 34     <-- 34 -->        PDF

The influence mechanism of slope direction effect on cypress regeneration – Utjecaj mehanizma ekspozicije na prirodnu obnovu obične azijske tuje
Regeneration capacity of regenerated cypress seedlings was significantly affected by slope direction,this may be because that the intensity and hours of sunshine vary with slope directions, thus resulting in great differences in water, heat, physical and chemical properties of soil (Sewerniak 2016). According to our investigation results, the sunshine time was short and the light intensity was only 112.76 lum/ft² on shady slope, and the evaporation of soil water was small, with natural water content reaching up to 33.07%. Unlike shady slope, the sunshine time was long and the light intensity was 184.08 lum/ft² on sunny slope, of course, that the evaporation of the soil water was large and the natural water content of soil was low, with only 28.83%. Cypress seedlings are mostly distributed on the shady slope and semi shady slope due to the different illumination conditions. The illumination on shady slope is less than that on sunny slope, and the soil is relatively wet, which is conducive to cypress renewal (Yu et al. 2013). Therefore, in the investigated forest, slope direction has become the dominant factor of NR of cypress in semi-arid areas.
The influence mechanism of gap area effect on cypress regeneration – Utjecaj mehanizma površine otvora na prirodnu obnovu obične azijske tuje
In addition, the number of regeneration seedlings was also affected by gap area (Figure7), and the larger gap area was favorable for cypress regeneration. This phenomenon is not difficult to understand for sun-loving cypress seedlings, where the forest gap areas create more abundant light conditions. Next, when they grow up gradually, the influence of gap area becomes smaller due to entering the stable growth period. Therefore, the correlation between the number of cypress seedlings and gap area decreased with the height (grade). Generally, the factor of light was first changed by the formation of forest gap. the relatively large density of plantation results in insufficient light in the forest and a slow NR process. Therefore, with the increase of the gap area, the understory plants get more illumination time, more comprehensive light quality, and more physiologically effective radiation (Chen et al. 2018). Also, the distribution pattern of ambient temperature, humidity, and water resources around the understory plants (including cypress seedlings) also changed. Finally, the purpose of promoting cypress renewal was achieved. In short, in the investigated forest,the larger area of the forest gap, the better lighting conditions in the forest gap, more conducive to the regeneration of cypress seedlings.
Conclusion and prospective – Zaključak i perspektiva
In the investigated forest, compared with other tree species, the density and frequency of cypress regeneration seedlings are larger. The height distribution of cypress regeneration seedlings is mainly grade I seedlings, and there are few grade II, III, and IV regeneration seedlings. Thus, in future research, how to improve the survival rate of Grades II, III, and IV cypress regeneration seedlings could be studied.
In this study, the progress of cypress seedlings regeneration naturally was affected by stand factors and environmental factors. Especially, in stand factors, high density of herb was unfavorable to cypress regeneration while high moss coverage was contrary; in environmental factors, soil stone content, slope direction, and forest gap area were important environmental factors for promoting cypress regeneration. In the future management of cypress plantations, stand factors and environmental factors should be paid more attention to improve the regeneration of seedlings. For example, in the cypress seedling stage to properly loosen the soil, mix gravel particles or coarse materials into the soil to increase soil porosity, water permeability, and air permeability, timely watering and combing the grass to improve the light transmittance. In addition, the indexes of ground diameter and growth height of cypress regeneration seedlings are also related to the quality of regeneration status. Therefore, in the future research, the research on the ground diameter and growth index of cypress regeneration seedlings should be supplemented.
Acknowledgements – Priznanja
Not applicable.
Funding – Financiranje
This study was supported by Research, Development and Experimental Demonstration of Key Technologies for Karst Natural Landscape Restoration and Vegetation Ecological Function Improvement in Lijiang River Basin [2019YFC0507503]. Longji Terraced landscape sustainability utilization technology integration and tourism industry demonstration[20180102], Smart Scenic Area Tourist Safety Warning System and Distinctive Culture Space-time Virtual Reconstruction Technology Development and Application Demonstration[20170220], Data Mining based College and University On-line Learning Condition Trace System [2021KY1514].
Conflict of interest – Sukob interesa
The authors declare that they have no competing interests.
References
Reference
Barton, A.M., and H.M. Poulos, 2018: Response of Arizona cypress (Hesperocyparis arizonica) to the Horseshoe Two Megafire in a south-eastern Arizona Sky Island mountain range. International Journal of Wildland Fire 28:62-69.