Multiparameter analysis of vertical vegetation structure based on digital image processing

Zehm, Andreas; Nobis, Michael P.; Schwabe, Angelika

doi:10.1078/0367-2530-00086

Cited by 75 publications

(63 citation statements)

References 32 publications

(41 reference statements)

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“…The distance from the camera to Robel, 1970;Vermeire and Gillen, 2001;Sritarapipat et al, 2014 , or the board or sheet of ca. 1 1 m Zehm et al, 2003;Limb et al, 2007 . However, those materials were not suitable for the objectives of this study because the width of the scale bar was too narrow to cover the space occupied by the four target rice plants and a board would have disturbed the local environment and it would have been difficult to maintain the board in position during the entire measurement period.…”

Section: Study Site and Experimental Cropmentioning

confidence: 99%

“…Thus far, most methods using the visual obstruction method in outdoor fields, rather than indoor settings such as plant factories Hartmann et al, 2011;Li et al, 2014 , have not been carried out continuously. In other words, measurements were only taken sporadically Zehm et al, 2003;Limb et al, 2007. Sritarapipat et al 2014 employed a similar approach to that of the current study by measuring plants in a rice field using a scale bar and imaging processing band selection, filtering and thresholding .…”

Section: Specific Features Of the Developed Plant Height Measurement mentioning

confidence: 99%

“…Second, the measurement area is limited because of the narrow diameter of the Robel pole. Hence, this method has been modified to incorporate the use of a board or sheet with a scale on it to extend the measurement area Zehm et al, 2003;Limb et al, 2007 . This modification enables measuring a larger area, but it is not suitable for continuous measurements in situ for the following reasons: it would be difficult to maintain the board or sheet in situ i.e.…”

Section: Introductionmentioning

confidence: 99%

“…To accommodate frequent or continuous measurement, film or digital cameras have been incorporated into plant measurement systems to capture images frequently over long periods Sritarapipat et al, 2014;Constantino et al, 2015 . The limited measurement length and resolution of the Robel pole has also been improved upon by modifying its length and marking interval frequency or using another pole or scale appropriate to the study site conditions and target plant Barkman, 1988;Zehm et al, 2003 . In more complex approaches, plant heights are estimated using a light-field camera that can take images with different focal planes Schima et al, 2016 or by using a laser beam to determine the distance to the plant from a sensor Tilly et al, 2014;Friedli et al, 2016 . In other studies, an ultrasonic sensor or a camera has been mounted on a land vehicle Andújar et al, 2012 or an unmanned aerial vehicle Anthony et al, 2014 to estimate plant heights at the site scale level.…”

Section: Introductionmentioning

confidence: 99%

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Precise and continuous measurement of plant heights in an agricultural field using a time-lapse camera

Mano

2017

J. Agric. Meteorol.

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Plant height is an important trait linked to yield potential and phenotyping; hence, a method for measuring plant height with sufficient temporal and spatial resolutions is required. Furthermore, a low-cost and easy-to-use method is desirable for practical application in agricultural fields. In previous studies, methods for measuring plant height have only fulfilled one or a few of these requirements, and there have been very few studies that have attempted to fulfill all the above requirements in one method. The current study proposes a low-cost plant height measurement system using a commercial time-lapse camera to capture seasonal and year-to-year variations in plant height that represent plant heights at the site scale. The system's performance was tested in a rice field in Japan for two growing seasons. Plant heights were determined to the nearest 1-cm in height from the camera images by referencing a scale bar that was erected next to the four target plants. The obtained plant heights were corrected for vertical distortion referred to as the 'displacement effect' in the main text , and those were compared with the direct height measurements for each the target plant and site-scaled plant heights that were averaged from 10 samples. For both cases, good agreement between the captured and referenced plant heights was obtained. The system was able to reflect detailed seasonal variations in the plant heights including the maximum heights and the times at which they occurred as well as year-to-year differences. Consequently, the developed system appears to fulfill all the necessary requirements for practical measurement of plant height on-site in agricultural fields.

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Section: Study Site and Experimental Cropmentioning

confidence: 99%

Section: Specific Features Of the Developed Plant Height Measurement mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Precise and continuous measurement of plant heights in an agricultural field using a time-lapse camera

Mano

2017

J. Agric. Meteorol.

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“…To measure heterogeneity of the vertical structure of the vegetation, the VESTA (Vertical Vegetation Structure Analysis) photographic method was performed (Zehm et al, 2003).…”

Section: Environmental Conditionsmentioning

confidence: 99%

Evaluation of the design effects of different agropastoral systems on the diversity and density of spiders

Almada

González

Corronca³

2017

Span. j. agric. res.

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Sustainable agro-ecological design is challenging when the goal is self-regulation of the system. The objective of this study was to evaluate if the agropastoral design system affects the spider community, as spiders are the main predators in these production systems, and to determine those designs which maximize the diversity and density of spiders. The study was conducted during 2009/2010, at the Experimental Research Station of Agriculture (EEA-INTA) Reconquista (Santa Fe, Argentina) where we considered four different designs: C1 (five agricultural fields), C2 (three agricultural fields and fourlivestock fields), C3 (six agricultural fields and one livestock field) and C4 (five agricultural fields and one forest area). In each design, the spiders were collected by pitfall traps and suction samples with a G-Vac (garden-vacuum). The designs proposed were considered on the basis of environmental heterogeneity. The C4 treatment had the greatest number of species, followed by C2, C3 and C1 (183, 178, 144 and 142 species, respectively), and C2 presented the greatest abundance of spiders followed by C4, C3 and C1 (n=5708, 4785, 4271 and 3448, respectively). Eight guilds were present in C3 and C4. This study is the first to evaluate the diversity of spiders in agropastoral systems in Argentina. Our results show that designs that include more fields with livestock orequal to those for agriculture, as well as forest areas, increase environmental heterogeneity. Therefore, the presence of a biological controller and dominant predatory group will be possible with sustainable designs that have environmental heterogeneity, contributing to improved pest control in agricultural systems.Additional key words: araneofauna; agro-ecological design; biological control; environmental heterogeneity.Correspondence should be addressed to Melina S. Almada: almadamelina@gmail.com

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Drivers of community assembly in tropical forest restoration sites: role of local environment, landscape, and space

Audino

Murphy

Zambaldi

et al. 2017

Ecological Applications

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There is increasing recognition that community assembly theory can offer valuable insights for ecological restoration. We studied community assembly processes following tropical forest restoration efforts, using dung beetles (Scarabaeinae) as a focal taxon to investigate taxonomic and functional patterns of biodiversity recovery. We evaluated the relative importance of the local environment (i.e., canopy cover, understory cover, tree basal area, and soil texture), landscape context (i.e., habitat patch proximity and availability and percentage of surrounding area classified as natural forest or Eucalyptus spp. plantation), and space (i.e., spatial proximity of the study areas to estimate dispersal limitation or unmeasured spatially structured processes) on dung beetle species and functional trait composition across a gradient of 15 restoration sites in Brazilian Atlantic Forest. We also assessed which factors were the primary determinants in the establishment of individual dung beetle functional groups, classified according to size, food relocation habit, diet, and period of flight activity. Both species and functional trait composition were most strongly influenced by the local environment, indicating that assembly was predominantly driven by niche-based processes. Most of the variation explained by space was co-explained by local environment and landscape context, ruling out a strong influence of dispersal limitation and random colonization on assembly following restoration. In addition, nearly all of the variance explained by landscape context was co-explained by local environment, suggesting that arrival and establishment at a site depends on both local and landscape-scale environmental factors. Despite strong evidence for niche-based assembly, a large amount of variation remained unexplained in all models, suggesting that stochastic processes and/or unmeasured environmental variables also play an important role. The relative importance of local environment, landscape context, and space changed considerably when analyzing the assembly mechanisms of each functional group separately. Therefore, to recover distinct functional traits in restoration sites, it may be necessary to manipulate different components of the local environment and surrounding landscape. Overall, this study shows that assembly rules can help to better understand recovery processes, enabling improvement of future restoration efforts.

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Multiparameter analysis of vertical vegetation structure based on digital image processing

Cited by 75 publications

References 32 publications

Precise and continuous measurement of plant heights in an agricultural field using a time-lapse camera

Precise and continuous measurement of plant heights in an agricultural field using a time-lapse camera

Evaluation of the design effects of different agropastoral systems on the diversity and density of spiders

Drivers of community assembly in tropical forest restoration sites: role of local environment, landscape, and space

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