Crop traits relevant for selecting potato genotypes adapted to low nitrogen availability

Canopy cover development was measured for 6 to 18 different potato varieties, under 3 different nitrogen regimes. This canopy cover development can be expressed in several paramaters. Of these parameters, the 'Area Under Cover Progress Curve' and the 'percentage of maximal ground cover' show the highest correlation with the final yield in low-nitogen conditions

Canopy Cover

Canopy Cover Workshee

Comparison of visual assessment and digital image analysis for canopy cover estimation

Nowadays, in the context of agriculture, cover crops are crops cultivated with the sole aim of providing important ecosystem services such as erosion prevention. Many services offered by these crops are directly linked to the development of their vegetation, and especially of canopy cover. A proper estimation of this cover is thus necessary to evaluate cover crop performance. Many methods to estimate canopy cover exist, but differ in terms of effort and time needed to implement them. In this study, we compared visual assessment of canopy cover in the field with two methods of digital image analysis (Assess and Canopeo), for different cover crop species and vegetation types. Visual estimation was positively correlated with both type of image analysis estimations. However, it showed systematically lower values of canopy cover, especially at intermediate canopy cover values. The type of vegetation influenced the visual and digital image estimations, narrow leaf species being the most difficult to evaluate visually. This study showed that depending on its utilisation, visual canopy cover assessment could be useful, especially when only relative estimation of canopy cover is needed. When absolute canopy cover estimation is needed, the use of digital image analysis should be preferred

Evaluation of Effectiveness and Cost-Benefits of Woolen Roadside Reclamation Products

This research project developed three types of products for study: woolen erosion control blankets (ECBs), wool incorporated into wood fiber compost at a 40:1 ratio (compost to wool, by weight), and wool incorporated into silt fence. The project, supported by Montana Department of Transportation (MDT) and the Center for Environmentally Sustainable Transportation in Cold Climates, compared the wool products’ performance to roadside reclamation products commonly used for revegetating cut slopes: straw/coconut (coir) ECB, wood fiber compost and woven plastic silt fence. Three versions of wool silt fence were developed by the project, yet, even more versions are needed to arrive at a commercially viable product. Wool silt fence was the least promising of the three types of reclamation materials. The primary measure for success for ECBs and wool additive to the compost was the amount of seeded or desired vegetation they established after two growing seasons. The research team evaluated the performance of the woolen and standard products by measuring the percentage of canopy cover of each plant species present in each treatment plot. Canopy cover measures the percentage of ground that is covered by a vertical projection of a plant’s foliage. To conduct the comparative analysis, researchers calculated an average percent canopy cover for each functional group: seeded native grasses, desired non-seeded (volunteer) grasses and forbs, and weeds. There was no statistical difference in the mean canopy cover of seeded grass species of the compost treatment (control) compared to the cut wool with compost treatment, 6.4% and 10.2%, respectively. Thus, the project could not determine that cut wool pieces provided a benefit to plant establishment and growth when it is added to compost material. Further experimentation to determine the ideal ratio of wool pieces to add to compost is warranted. The two best performing treatments (i.e. greatest seeded grass establishment) were the rolled wool/straw ECBs. The 100% wool ECB and 50% wool/50% straw ECB had the greatest mean seeded grass canopy cover after two years. Both of these wool ECBs had more seeded grass canopy cover than the standard 70% straw/30% coir ECB demonstrating their potential as a commercially viable product for roadside revegetation applications. Laboratory tests of the wool/straw ECB demonstrated it was comparable to the specifications of a short-term (Type II B or C) standard ECB used along MDT roadways. Future product development of the wool/straw ECB should focus on improving the shear strength at high flows so it meets all required Type III specifications

Estimation of vegetation cover at subpixel resolution using LANDSAT data

The present report summarizes the various approaches relevant to estimating canopy cover at subpixel resolution. The approaches are based on physical models of radiative transfer in non-homogeneous canopies and on empirical methods. The effects of vegetation shadows and topography are examined. Simple versions of the model are tested, using the Taos, New Mexico Study Area database. Emphasis has been placed on using relatively simple models requiring only one or two bands. Although most methods require some degree of ground truth, a two-band method is investigated whereby the percent cover can be estimated without ground truth by examining the limits of the data space. Future work is proposed which will incorporate additional surface parameters into the canopy cover algorithm, such as topography, leaf area, or shadows. The method involves deriving a probability density function for the percent canopy cover based on the joint probability density function of the observed radiances

ESTIMASI KANDUNGAN KARBON TEGAKAN HUTAN DI ATAS PERMUKAAN TANAH PADA BERBAGAI KELAS TUTUPAN TAJUK DI HUTAN ADAT PENGAJIT KABUPATEN BENGKAYANG

Forests are the largest component that is able to absorb carbon through photosynthesis process and store carbon in forests biomass per unit area. The aim of this study was to estimate the carbon that stored in above ground forest in Pengajit customary forest of Bengkayang regency. The method used in this study was non destructive by surveying the diameter and the species of forest. The results of this study showed that carbon stock of above groud forest in Pengajit customary forest was vary on each canopy cover class. The biggest carbon found at the dense canopy cover class was 299,74 tons/ha, and the medium canopy cover class had 235,67 tons/ha carbon stock, while the smallest carbon stock value was 55,89 tons/ha at the lowest canopy cover class. Total carbon stocks that found at the dense conopy cover class was 26.124,19 tons, the medium canopy cover class stored 1.397,53 tons, and the lowest canopy cover class had 428,25 tons. Pengajit customary forest as a whole saved 27.949,97 tons carbon stocks.Keywords : Canopy cover class, carbon stock, customary forest, forest stan

HATCHLING SEX RATIOS AND LOCOMOTOR PERFORMANCE OF MIDLAND PAINTED TURTLES (CHRYSEMYS PICTA MARGINATA)

The primary objectives of this study were to understand how canopy cover and nest temperatures affect hatchling sex ratios and locomotor performance (i.e., swimming sprint speed and righting response) of Chrysemys picta marginata nests. Seventeen nests were monitored with temperature data-loggers during the 2009 nesting season and found to contain 100% male-biased clutches with a mean nest temperature range of 20.0–24.0°C during the thermosensitive period (TSP). The percentage of canopy cover over each nest was inversely and significantly correlated with mean nest temperatures experienced during the TSP. Mean nest temperatures (MNT) did not have a statistical effect on either measure of locomotor performance; however, there was an observed trend toward increased performance with increased MNT

Utilizing National Agriculture Imagery Program Data to Estimate Tree Cover and Biomass of Piñon and Juniper Woodlands

With the encroachment of piñon (Pinus ssp.) and juniper (Juniperus ssp.) woodlands onto sagebrush steppe rangelands, there is an increasing interest in rapid, accurate, and inexpensive quantification methods to estimate tree canopy cover and aboveground biomass. The objectives of this study were 1) to evaluate the relationship and agreement of piñon and juniper (P-J) canopy cover estimates, using object-based image analysis (OBIA) techniques and National Agriculture Imagery Program (NAIP, 1-m pixel resolution) imagery with ground measurements, and 2) to investigate the relationship between remotely-sensed P-J canopy cover and ground-measured aboveground biomass. For the OBIA, we used eCognition® Developer 8.8 software to extract tree canopy cover from NAIP imagery across 12 P-J woodlands within the Sagebrush Steppe Treatment Evaluation Project (SageSTEP) network. The P-J woodlands were categorized based on the dominant tree species found at the individual sites for the analysis (western juniper, Utah juniper, and mixed P-J community). Following tree canopy cover extractions, relationships were assessed between remotely-sensed canopy cover and ground-measured aboveground biomass. Our OBIA estimates for P-J canopy cover were highly correlated with ground-measured tree canopy cover (averaged across all regions r = 0.92). However, differences between methods occurred for western and Utah juniper sites (P \u3c 0.05), and were more prominent where tree canopy cover was \u3e 40%. There were high degrees of correlation between predicted aboveground biomass estimates with the use of remotely-sensed tree canopy cover and ground-measured aboveground biomass (averaged across all regions r = 0.89). Our results suggest that OBIA methods combined with NAIP imagery can provide land managers with quantitative data that can be used to evaluate P-J woodland cover and aboveground biomass rapidly, on broad scales. Although some accuracy and precision may be lost when utilizing aerial imagery to identify P-J canopy cover and aboveground biomass, it is a reasonable alternative to ground monitoring and inventory practices

Assessing Efficacy of Restoration Treatments in Juniper Savannas using Spatial Wavelets and Dot Grids on Aerial Photography

Across much of their diverse natural range in the Western US, species of the genus juniperus are expanding onto open grass and shrublands and infilling open woodland areas. In Southern Arizona’s Clifton Ranger District, landscape-scale restoration treatments have been used to stall this expansion and reduce canopy-cover. This study utilizes and compares two techniques – dot- grid sampling and spatial wavelet analysis (SWA) – to estimate the efficacy of these treatments by measuring canopy-cover change pre-and post-treatment. Further, using the SWA dataset, the study explores the potential of SWA for landscape-scale ecological attribute estimation. This study found that restoration treatments significantly reduced canopy-cover with 18% and 42% mean reductions (p \u3c 0.001), depending on treatment. The ability of SWA to estimate canopy- cover, and crown diameter was good in open canopy-cover (EF values up to 0.587 for canopy- cover estimation and 0.558 for crown diameter estimation), but diminished as canopy-cover increased, and systematically under-estimated as canopy-cover and crown diameter increased. Further, SWA showed that the potential for legacy tree and juniper expansion mapping was promising (68 to 79% of legacy trees correctly identified). Huge quantities of data and high technical complexity make SWA unsuitable for widespread adoption without addition of user- friendly interface, but the quantity and quality of data suggests a vast utility in future forest and rangeland research and management