scholarly journals Leaf chlorophyll estimates of temperate deciduous shrubs during autumn senescence using a SPAD-502 meter and calibration with extracted chlorophyll

2020 ◽  
Vol 77 (2) ◽  
Author(s):  
Alison Donnelly ◽  
Rong Yu ◽  
Chloe Rehberg ◽  
Gretchen Meyer ◽  
Erica B. Young
Keyword(s):  
Leaf Chlorophyll ◽  
Temperate Deciduous ◽  
Deciduous Shrubs ◽  
Autumn Senescence

scholarly journals Response of Container-grown Nursery Plants to Chlorine Used to Disinfest Irrigation Water

HortScience ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 164-167 ◽  
Author(s):  
Diane Feliciano Cayanan ◽  
Mike Dixon ◽  
Youbin Zheng ◽  
Jennifer Llewellyn
Keyword(s):  
Irrigation Water ◽  
Picea Glauca ◽  
Plant Pathogens ◽  
Free Chlorine ◽  
Growth Reduction ◽  
Leaf Chlorophyll ◽  
Physocarpus Opulifolius ◽  
Deciduous Shrubs ◽  
Chamaecyparis Pisifera ◽  
Weigela Florida

The recycling of irrigation water may cause the dispersal of plant pathogens. Irrigation water disinfected with 2.4 mg·L−1 of free chlorine for 5 min was overhead-applied to 17 container-grown nursery plants for 11 weeks in a commercial nursery to evaluate the response of container-grown nursery plants to chlorine. No visual symptoms of injury or growth reduction were observed on the evergreen shrubs (Juniperus horizontalis, Thuja occidentalis, Buxus microphylla, Picea glauca, Rhododendron catawbiense, Taxus media, and Chamaecyparis pisifera), but there were visual injuries and/or growth reduction on some of the deciduous shrubs (Salix integra, Hydrangea paniculata, Prunus ×cistena, Weigela florida, Physocarpus opulifolius). Symptoms of anthracnose were reduced on Cornus alba plants treated with chlorinated water. The chlorine treatment did not affect leaf chlorophyll content. The chlorine treatment killed all fungi and oomycetes in the irrigation water (DNA multiscan). Although there were visible leaf injuries and growth reduction on some of the deciduous plants, chlorine injury did not render them unsalable. Results suggest that irrigation water treated with 2.4 mg·L−1 free chlorine for 5 min will effectively control the dispersal of common plant pathogens without reducing the market value of container-grown plants.

scholarly journals Effects of a Short-Term Trampling Experiment on Alpine Vegetation in the Tatras, Slovakia

2021 ◽  
Vol 13 (5) ◽  
pp. 2750
Author(s):  
Veronika Piscová ◽  
Michal Ševčík ◽  
Juraj Hreško ◽  
František Petrovič
Keyword(s):  
Outdoor Recreation ◽  
Plant Cover ◽  
Short Term ◽  
Recreational Activities ◽  
Small Areas ◽  
Management Plans ◽  
Deciduous Shrubs ◽  
Negative Impacts ◽  
Potential Damage ◽  
Alpine Communities

Over the past decades, outdoor recreation in mountains has become progressively more important and as a result human induced potential damage has increased. Alpine communities are particularly susceptible to human recreational activities, such as tourist trampling. Although there are a number of studies that explicitly assess the effects of trampling on alpine communities, they do not reflect on terrains with a rich topography and the presence of more communities in very small areas. In this study, effects of short-term trampling on some alpine communities in the Tatras, the highest mountains of the Carpathians, were studied experimentally. Vulnerability to disturbance was compared among plant communities in terms of resistance and resilience, which are based on cover measurements. With proximity to trampling intensity, we found a significant decrease in plant cover and abundance of deciduous shrubs, lichens, and mosses. These results demonstrate that human trampling in alpine communities has major negative impacts on lichen and moss abundance and species richness. A short-term trampling experiment required several years of community regeneration. Therefore, management plans should discourage hiking activity off paths and restrict recreational activities.

Common Bermudagrass (Cynodon dactylon) Interference in Newly Planted Peach (Prunus persica) Trees

Weed Science ◽  
1985 ◽  
Vol 33 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Stephen C. Weller ◽  
Walter A. Skroch ◽  
Thomas J. Monaco
Keyword(s):  
Field Experiments ◽  
Prunus Persica ◽  
Cynodon Dactylon ◽  
Ground Cover ◽  
First Year ◽  
Allelopathic Effect ◽  
Trunk Diameter ◽  
Leaf Chlorophyll ◽  
Tree Leaf ◽  
Common Bermudagrass

Field experiments conducted over a 2-yr period demonstrated that common bermudagrass [Cynodon dactylon (L.) Pers. # CYNDA] inhibited growth of newly planted peach (Prunus persica L. ‘Norman’) trees. Common bermudagrass densities of 100, 75, 50, and 25% ground cover reduced tree fresh weight by 86, 64, 43, and 19%, respectively, the first year (1978) and 87, 62, 44, and 28%, respectively, the second year (1979) after planting. Tree trunk diameter relative growth rate (RGR) was reduced by 75 and 100% common bermudagrass ground cover densities at all measurement dates only in 1978. Tree leaf N and K were reduced in both years by common bermudagrass; however, only at the 100% common bermudagrass density in 1978 was N at a deficient level. Leaf chlorophyll was reduced in trees grown in all densities of common bermudagrass only in 1978. Reduced tree growth cannot be explained entirely by competition for essential nutrients; thus an allelopathic effect of the bermudagrass on young peach roots is suspected.

scholarly journals Can vegetation index track the interannual variation in gross primary production of temperate deciduous forests?

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Fan Liu ◽  
Chuankuan Wang ◽  
Xingchang Wang
Keyword(s):  
Primary Production ◽  
Vegetation Index ◽  
Near Infrared ◽  
Deciduous Forest ◽  
Gross Primary Production ◽  
Growing Season ◽  
Temperate Deciduous Forest ◽  
Near Infrared Reflectance ◽  
Modis Ndvi ◽  
Temperate Deciduous

Abstract Background Vegetation indices (VIs) by remote sensing are widely used as simple proxies of the gross primary production (GPP) of vegetation, but their performances in capturing the inter-annual variation (IAV) in GPP remain uncertain. Methods We evaluated the performances of various VIs in tracking the IAV in GPP estimated by eddy covariance in a temperate deciduous forest of Northeast China. The VIs assessed included the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), and the near-infrared reflectance of vegetation (NIRv) obtained from tower-radiometers (broadband) and the Moderate Resolution Imaging Spectroradiometer (MODIS), respectively. Results We found that 25%–35% amplitude of the broadband EVI tracked the start of growing season derived by GPP (R2: 0.56–0.60, bias < 4 d), while 45% (or 50%) amplitudes of broadband (or MODIS) NDVI represented the end of growing season estimated by GPP (R2: 0.58–0.67, bias < 3 d). However, all the VIs failed to characterize the summer peaks of GPP. The growing-season integrals but not averaged values of the broadband NDVI, MODIS NIRv and EVI were robust surrogates of the IAV in GPP (R2: 0.40–0.67). Conclusion These findings illustrate that specific VIs are effective only to capture the GPP phenology but not the GPP peak, while the integral VIs have the potential to mirror the IAV in GPP.

Water Relations and Productivity of Alfalfa Leaf Chlorophyll Variants

Crop Science ◽  
1991 ◽  
Vol 31 (5) ◽  
pp. 1229-1233 ◽  
Author(s):  
K. Estill ◽  
R. H. Delaney ◽  
W. K. Smith ◽  
R. L. Ditterline
Keyword(s):  
Water Relations ◽  
Leaf Chlorophyll ◽  
Alfalfa Leaf
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