Abstract
Light is a limiting resource for crops within integrated land use systems especially those including woody perennials. The amount of available light at ground level can be modified by artificially pruning the overstory. Aiming to increase the understanding of light management strategies, we simulated the pruning of wild cherry trees and compared the shading effects of the resulting tree structures over a complete growing season, with fine spatiotemporal resolution. Original 3D-tree structures were retrieved employing terrestrial laser scanning and quantitative structure models, and subjected to two pruning treatments at low and high intensities. By using the ‘shadow model’, the analogous tree structures created diverse shaded scenarios varying in size and intensity of insolation reduction. Conventional pruning treatments reduced the crown structure to the uppermost portion of the tree bole, reducing the shading effects, and thus, shrinking the shaded area on the ground by up to 38%, together with the shading intensity. As an alternative, the selective removal of branches reduced the shading effects, while keeping a more similar spatial distribution compared to the unpruned tree. Hence, the virtual pruning of tree structures can support designing and selecting adequate tending operations for the management of light distribution in agroforestry systems. The evidence assembled in this study is highly relevant for agroecosystems and can be strategically used for maintaining, planning and designing integrated tree-crop agricultural systems.
Highlights
Pruning is observed as a natural phenomenon the shedding of suppressed or dead branches, and as a manmade management intervention, for the selective removal of woody and non-woody plant parts
In order to improve the performance of the shadow model, we reduced the number of cylinders of the quantitative structure models (QSMs) of trees by using the simplify_qsm function of TreeQSM, with 1 or 2 replacement iterations
The effect of individual pruning treatments on tree structures is summarised in Table S3 (Online Resource 1), in terms of retained and removed woody volume, together with the total leaf area at full crown expansion
Summary
Pruning is observed as a natural phenomenon the shedding of suppressed or dead branches, and as a manmade management intervention, for the selective removal of woody and non-woody plant parts. Pruning has been reported to increase the quantity and improve the distribution of light at the ground level, triggering modifications in the shaded habitats, which can be especially important in mixed cropping systems (Dupraz and Liagre 2011; Kang et al 1981, 1985; Kumar et al 2010; Miah et al 1994; Springmann et al 2011). The availability of light is perhaps the most important limitation on the performance of food crops (Miah et al 1994). To this end, established woody perennials have an advantage over annual crops, due to their long-lasting and dynamically evolving structures, often leading to an uneven light competition over the systems’ productive cycle. In the context of a changing climate, the shade cast by trees might play a significant role in mitigating negative effects towards crop vitality and production losses (Valladares et al 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
