scholarly journals Sargassum epifaunal communities vary with canopy size, predator biomass and seascape setting within a fringing coral reef ecosystem

2020 ◽  
Vol 640 ◽  
pp. 17-30 ◽  
Author(s):  
YY Chen ◽  
P Cooper ◽  
CJ Fulton
Keyword(s):  
Canopy Structure ◽  
Dry Weight ◽  
Marine Biodiversity ◽  
Fish Biomass ◽  
Back Reef ◽  
Canopy Volume ◽  
Local Patch ◽  
Secondary Productivity ◽  
Canopy Size ◽  
Reef Ecosystem

Tropical seascapes are comprised of a range of patch habitat types, yet we have only a partial understanding of how local patch condition and seascape position may influence patterns of marine biodiversity, particularly for invertebrate taxa. We investigated how the epifaunal abundance and biomass of tropical Sargassum varied with canopy size (volume, total length and dry weight), local patch conditions (macroalgal composition, canopy structure and invertivorous fish biomass) and seascape setting (nearshore, lagoon and back reef) within the Ningaloo fringing reef ecosystem, Australia. A total of 49431 epifauna, dominated by crustaceans and molluscs, were extracted from the thalli of 81 tropical Sargassum polycystum individuals. Epifaunal abundance and biomass were most strongly correlated with host Sargassum canopy volume and dry weight, respectively. Epifaunal abundance and biomass also varied significantly among separate Sargassum meadow patches, with a significant interaction between canopy size and seascape position. Considerable site-level variations in epifaunal biomass density (mg per g Sargassum dry weight) were best predicted by either seascape context or local invertivorous fish biomass. Sargassum within meadows furthest from the back reef tended to have the highest epifaunal biomass (dominated by molluscs), while meadows closest to the back reef were dominated by crustacea. Sargassum within meadows with a high local abundance of invertivorous labrids and serranids tended to have the lowest epifaunal biomass. Strong Sargassum canopy size-epifauna relationships indicate that even small differences in canopy extent have major flow-on effects for the trophic function of tropical marine ecosystems by affecting the epifaunal secondary productivity available to higher-order consumers, such as fishes.

scholarly journals Effect of Planting Time on Canopy Structure and Biomass Production in Some Soybean Genotypes

1970 ◽  
pp. 25-29
Author(s):  
MK Uddin ◽  
MK Hasan ◽  
AKMA Alam
Keyword(s):  
Plant Height ◽  
Biomass Production ◽  
Dry Matter ◽  
Canopy Structure ◽  
Morphological Structure ◽  
Dry Weight ◽  
Shoot Biomass ◽  
Late Planting ◽  
Planting Time ◽  
Soybean Genotypes

A field experiment was conducted in the Field Laboratory of the Department of Crop Botany, BAU, Mymensingh during November 2003 to May 2004 to assess the effect of planting time (November and December) on some morphological structure, and root & shoot biomass production in four soybean genotypes (GPB-1, GPB-2, AGS-332 and AGS-11-35). The plant height, stem base diameter, seed dry weight plant-1 were significantly greater in the late planting crops (December) but number of branches plant-1, number of leaves plant-1, leaves dry weight plant-1, shoots dry weight plant-1, roots dry weight plant-1, total dry matter plant-1 were also significantly greater in November planting. Highest plant height, branches plant-1 and leaves plant-1, shoot dry weight plant-1 and total dry matter were found in GPB-2 genotype. Key words: Early and late planting, shoot and root mass, Glycine max. DOI = 10.3329/jard.v5i1.1453 J Agric Rural Dev 5(1&2), 25-29, June 2007

Influence of canopy structure on the understory environment in tall, old-growth, conifer forests

2000 ◽  
Vol 30 (8) ◽  
pp. 1231-1245 ◽  
Author(s):  
Robert Van Pelt ◽  
Jerry F Franklin
Keyword(s):  
Leaf Area ◽  
Canopy Structure ◽  
Field Measurements ◽  
Horizontal Distribution ◽  
Shrub Cover ◽  
Old Growth ◽  
Light Levels ◽  
Vertical Heterogeneity ◽  
Canopy Volume ◽  
Old Growth Forests

The effect of the spatial distribution of trees and foliage on understory conditions was examined in six tall old-growth forests along the Pacific Coast: two sites each in Washington, Oregon, and California. Detailed field measurements of crown parameters were collected on over 9000 trees encompassing over 14.5 ha in the stands. Crown parameters were used to construct a spatially explicit model useful in analyzing the variability of crown distributions in both vertical and horizontal dimensions. Sapwood measurements of over 400 trees in combination with published equations and 240 hemispherical photos were used to assess leaf area and understory light levels, respectively. Shrub and herb cover was used as a biological indicator of growing conditions in the understory. Although leaf area is often assumed to be correlated with the amount of light penetrating the canopy, this is not the case in tall, old-growth forests. The semivariance of the horizontal distribution of canopy volume was strongly correlated with shrub cover and understory light levels and was an overall predictor of canopy structure. This variability gives rise to potentially higher understory light levels and shrub cover values when compared with a forest lacking this vertical heterogeneity and may allow the stand to support a higher volume of foliage.

Himalayan yew: stand structure, canopy damage, regeneration and conservation strategy

1998 ◽  
Vol 25 (4) ◽  
pp. 334-341 ◽  
Author(s):  
H.C. RIKHARI ◽  
L.M.S. PALNI ◽  
S. SHARMA ◽  
S.K. NANDI
Keyword(s):  
Stand Structure ◽  
Canopy Structure ◽  
Conservation Strategy ◽  
Cancer Drug ◽  
Taxus Baccata ◽  
Area Index ◽  
Canopy Volume ◽  
Anti Cancer ◽  
Canopy Removal ◽  
Canopy Damage

Taxus baccata L. subsp. wallichiana (Zucc.) Pilger has come into prominence in recent times due to its uncontrolled harvesting from the Himalayan wilds for the extraction of the anti-cancer drug Taxol. It is a very slow growing tree with poor regeneration, and the extent of canopy damage is likely to have serious consequences on biomass yield, plant survival and natural regeneration by affecting 'seed' output. The present study in the Jageshwar area of the Central Himalaya aimed to determine the stand and canopy structure, microsite characteristics, extent of canopy removal, and regeneration in human-disturbed and undisturbed sites. The number of trees, saplings and seedlings varied amongst plots. Leaf area index and canopy volume increased with increasing circumference at breast height. Of the total canopy volume, 57.4% was found to have been removed from the study area (9.54 ha; representing about 8% of the total T. baccata habitat). Regeneration of the species was found to be better in moist and shady microsites at undisturbed locations than in disturbed sites. Efforts made thus far for its conservation, and future strategies are discussed.

scholarly journals UAV and ground-based imagery analysis detects canopy structure changes after canopy management applications

OENO One ◽  
2020 ◽  
Vol 54 (4) ◽  
pp. 1093-1103
Author(s):  
Jingyun Ouyang ◽  
Roberta De Bei ◽  
Sigfredo Fuentes ◽  
Cassandra Collins
Keyword(s):  
Vegetation Index ◽  
Management Practices ◽  
Canopy Structure ◽  
Area Index ◽  
Structure Changes ◽  
Grape Quality ◽  
Canopy Volume ◽  
Canopy Area ◽  
Plant Area Index ◽  
Canopy Management

Aim: To analyse unmanned aerial vehicle (UAV)-based imagery to assess canopy structural changes after the application of different canopy management practices in the vineyard.Methods and results: Four different canopy management practices: i–ii) leaf removal within the bunch zone (eastern side/both eastern and western sides), iii) bunch thinning and iv) shoot trimming were applied to grapevines at veraison, in a commercial Cabernet-Sauvignon vineyard in McLaren Vale, South Australia. UAV-based imagery captures were taken: i) before the canopy treatments, ii) after the treatments and iii) at harvest to assess the treatment outcomes. Canopy volume, projected canopy area and normalized difference vegetation index (NDVI) were derived from the analysis of RGB and multispectral imagery collected using the UAV. Plant area index (PAI) was calculated using the smartphone app VitiCanopy as a ground-based measurement for comparison with UAV-derived measurements. Results showed that all three types of UAV-based measurements detected changes in the canopy structure after the application of canopy management practices, except for the bunch thinning treatment. As expected, ground-based PAI was the only technique to effectively detect internal canopy structure changes caused by bunch thinning. Canopy volume and PAI were found to better detect variations in canopy structure compared to NDVI and projected canopy area. The latter were negatively affected by the interference of the trimmed shoots left on the ground.Conclusions: UAV-based tools can provide accurate assessments to some canopy management outcomes at the vineyard scale. Among different UAV-based measurements, canopy volume was more sensitive to changes in canopy structure, compared to NDVI and projected canopy area, and demonstrated a greater potential to assess the outcomes of a range of canopy management practices.  Significance and impact of the study: Canopy management practices are widely applied to regulate canopy growth, improve grape quality and reduce disease pressure in the bunch zone. Being able to detect major changes in canopy structure, with some limitations when the practice affects the internal structure (i.e., bunch thinning), UAV-based imagery analysis can be used to measure the outcome of common canopy management practices and it can improve the efficiency of vineyard management.  

scholarly journals Drought Tolerance Responses of Purple Lovegrass and ‘Adagio’ Maiden Grass

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1695-1699 ◽  
Author(s):  
Erin Alvarez ◽  
S.M. Scheiber ◽  
Richard C. Beeson ◽  
David R. Sandrock
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Sandy Soil ◽  
Dry Weight ◽  
Miscanthus Sinensis ◽  
Total Biomass ◽  
Shoot Dry Weight ◽  
Drought Tolerant ◽  
Species Being ◽  
Canopy Size

Nonnative Miscanthus sinensis Anderss ‘Adagio’ and native Eragrostis spectabilis (Pursh) Steud. were evaluated for drought tolerance in a rain-excluded landscape setting in sandy soil in response to irrigation application volumes of 0 L, 0.25 L, 0.5 L, or 0.75 L. As irrigation rates increased, plant mass, canopy size, and shoot-to-root ratios increased for both species, being greatest at the 0.75-L rate. Shoot dry weight, root dry weight, total biomass, and shoot-to-root ratios were greater for E. spectabilis than M. sinensis. Cumulative water stress integral was also greater for E. spectabilis. Greater growth in conjunction with higher cumulative water stress indicates the native E. spectabilis is anisohydric and more drought-tolerant than the isohydric nonnative M. sinensis.

scholarly journals Pre-transplant Root Ball Condition Influences Growth of Plumbago During Establishment

2007 ◽  
Vol 17 (4) ◽  
pp. 486-490 ◽  
Author(s):  
Sudeep Vyapari ◽  
S.M. Scheiber ◽  
E.L. Thralls
Keyword(s):  
Plant Growth ◽  
Growth Rates ◽  
Dry Weight ◽  
Total Biomass ◽  
Biomass Growth ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Canopy Size

Three root ball conditions—nonroot-bound (NRB), root-bound (RB), and root-bound sliced (RBS)—were evaluated for their effect on plant growth of plumbago (Plumbago auriculata) during establishment and postestablishment in the landscape. At transplant, NRB plants were smaller than other treatments. Canopy size, shoot dry weight, root dry weight, and total biomass growth rates were faster for NRB plants compared with RB or RBS. By 6 and 8 weeks after transplanting, respectively, biomass and canopy size were similar among treatments. Rootbound and RBS plants were similar indicating root ball slicing does not affect growth in the landscape.

scholarly journals Effect of Reclaimed Water and Drought on Salt-sensitive Perennials

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1095B-1095 ◽  
Author(s):  
Ursula Schuch
Keyword(s):  
Irrigation Water ◽  
Potable Water ◽  
Root Zone ◽  
Reclaimed Water ◽  
Dry Weight ◽  
Water Source ◽  
Total Dry Weight ◽  
Chilopsis Linearis ◽  
Canopy Size ◽  
Leaf Dry Weight

Four species of salt-sensitive perennials (Chilopsis linearis, Tecoma stans, Salviagreggii, and Verbena pulchella gracilior) were grown in containers and were irrigated with potable or reclaimed water. Electrical conductivity (EC) was 0.3 dS·m-1 for potable irrigation water and 1.0 dS·m-1 for reclaimed irrigation water. After 12 weeks of growing plants with reclaimed vs. potable water, C. linearis leaf dry weight was reduced by 15%, T. stans root dry weight was reduced by 41%, V. puchella gracilior stem dry weight was reduced by 35%, and S. greggii total dry weight was reduced by 56%. The increase in canopy size was calculated 4, 8, and 12 weeks after treatments began and was not affected by water source for C. linearis and T. stans, but was reduced for S. greggii and V. pulchella gracilior treated with reclaimed water. Up to 12% dieback and reduced flowering were observed on S. greggii irrigated with reclaimed water. Within 4 weeks of treatments, EC in the root zone was 0.5 dS·m-1 for plants irrigated with potable water and 1.9 dS·m-1 for those irrigated with reclaimed water. When exposed to drought, C. linearis and T. stans grown with reclaimed water maintained a more negative water potential as soil moisture was depleted. Osmotic potential started to increase significantly for both irrigation treatments when more than 25% moisture from fully saturated containers were lost. In general, plants irrigated with potable water sustained more damage than those irrigated with reclaimed water after recovering from a drought cycle.

scholarly journals Comment on “Demographic dynamics of the smallest marine vertebrates fuel coral reef ecosystem functioning”

Science ◽  
2019 ◽  
Vol 366 (6472) ◽  
pp. eaay9321 ◽  
Author(s):  
Jacob E. Allgeier ◽  
Timothy J. Cline
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Ecosystem Function ◽  
Ecosystem Functioning ◽  
Fish Biomass ◽  
Fish Production ◽  
Coral Reef Ecosystem ◽  
High Productivity ◽  
Demographic Dynamics ◽  
Reef Ecosystem

Brandl et al. (Reports, 21 June 2019, p. 1189) report that cryptobenthic fishes underpin coral reef ecosystem function by contributing ~60% of “consumed fish” biomass and ~20% of production. These results are artifacts of their simulation. Using their data and model, we show that cryptobenthic species contribute less than 4% to fish production, calling into question the extent to which they contribute to the high productivity of coral reefs.

Assessing Organic Nitrogen Acquisition of Ericoid Mycorrhizae in Highbush Blueberry (Vaccinium corymbosum L.) Plants by Using an 15N Tracer

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 467e-467
Author(s):  
Wei Qiang Yang ◽  
Barbara L. Goulart ◽  
K. Demchak
Keyword(s):  
Organic Nitrogen ◽  
Organic Amendments ◽  
Dry Weight ◽  
Forest Litter ◽  
Vaccinium Corymbosum ◽  
15N Tracer ◽  
Organic N ◽  
Highbush Blueberry ◽  
N Availability ◽  
Canopy Volume

The ability of mycorrhizal highbush blueberry plants to acquire soil organic nitrogen under different organic amendment regimes was investigated in a field experiment by using an 15N tracer. Plants inoculated with an ericoid mycorrhizal isolate from the genus Oidiodendron had lower leaf 15N enrichment than uninoculated plants, indicating mycorrhizal (M) plants absorbed more unlabeled soil nitrogen than nonmycorrhizal (NM) plants. The unlabeled nitrogen was presumably from soil organic N sources which might be less available to NM plants. M plants produced more plant dry weight and larger canopy volume, presumably as a result of improved N acquisition ability. In the study, the effect of pre-plant organic amendments on the growth of highbush blueberry plants was clearly demonstrated. The forest litter amendment produced higher dry mass than either the rotted sawdust amendment or no amendment. The rotted sawdust amendment produced the smallest plants. These results suggested that organic amendments with different C:N ratios might have affected soil N availability by affecting the N mineralization process. The implication of these findings in the production of highbush blueberry in mineral soils will be discussed.

A Dynamic Model for the Relationship between Rice Growth and Meteorology, Water, Nitrogen, and Canopy Structure

2021 ◽  
Vol 64 (5) ◽  
pp. 1581-1610
Author(s):  
Kenichi Tatsumi
Keyword(s):  
Growth Model ◽  
Canopy Structure ◽  
Growth Dynamics ◽  
Dry Weight ◽  
Crop Growth ◽  
Initial Slope ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Rice Cultivars ◽  
Rice Growth

HighlightsA simulation model was built for understanding rice growth dynamics.Two rice cultivars under two nitrogen fertilization conditions were simulated.Simulated dry weight agreed well with the measured values.Daily maximum temperature was negatively correlated with rice growth.Abstract. Crop growth models are highly effective tools for solving various practical problems in agriculture, such as farm decision-making, agronomic management, and prediction of climate change impact on crop growth. This article presents a robust model to explain the dynamics among microclimate, canopy structure, and rice biomass growth based on ecological, physiological, and physical processes. Meteorological values, leaf area index (LAI), plant height, and dry weight of leaf, stem, and panicle were intermittently measured in the field for two rice cultivars under two different nitrogen (N) fertilization conditions during the 2017 and 2018 growing periods. Based on these measurements, a comprehensive and robust growth model, the Integrated Rice Growth Model (iRGM), was developed for rice growth simulations under various meteorological, fertilizer, and water conditions. The results showed that the iRGM provided sufficient quantitative explanations for the measured rice growth dynamics in the field compared with the ORYZA2000 model. Moreover, parameter sensitivity analyses showed that the initial slope of the light response curve had a significant effect on the dry weight throughout the growing period. Growth conversion efficiency, maintenance respiration rate, and daily increase in LAI also had larger influences on rice growth. On the other hand, the maximum temperature, which increased by 10% over the values obtained in the rice field, was negatively correlated with growth. This model would be useful for quantitative evaluations and predictions of complex systems encountered in environmental management and cultivar stability. Keywords: Canopy structure, Dry weight, Microclimate, Rice dynamic growth model, Sensitivity analysis.

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