scholarly journals Spadicoides palmicola sp.nov. on Licuala sp. from Brunei, and a note on Spadicoides heterocolorata comb.nov.

1998 ◽  
Vol 76 (10) ◽  
pp. 1698-1702 ◽  
Author(s):  
T K Goh ◽  
K D Hyde
Keyword(s):  
Tropical Fungi ◽  
Senescent Leaf ◽  
Palm Fungi

Spadicoides palmicola sp.nov. is described from a senescent leaf of Licuala sp. collected in Brunei. It differs from other Spadicoides species in having verruculose conidiophores producing verrucose, obclavate, rostrate, multi-euseptate, versicoloured conidia. Spadicoides obclavata Kuthub. & Nawawi var. heterocolorata R.F. Castañeda, Guarro & Cano is considered distinct from Spadicoides obclavata, and Spadicoides heterocolorata comb.nov. is proposed.Key words: Hyphomycetes, Licuala, palm fungi, systematics, tropical fungi.

Photosynthetic characteristics of senescent leaf induced by high planting den-sity of maize at heading stage in the field

2019 ◽  
Vol 45 (2) ◽  
pp. 248 ◽  
Author(s):  
Han-Yu WU ◽  
Ya-Jun ZHANG ◽  
Wang-Feng ZHANG ◽  
Ke-Ru WANG ◽  
Shao-Kun LI ◽  
...  
Keyword(s):  
Photosynthetic Characteristics ◽  
Senescent Leaf ◽  
Heading Stage

scholarly journals Effects of light and temperature on isoprene emission at different leaf developmental stages of eschweilera coriacea in central Amazon

2014 ◽  
Vol 44 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Eliane Gomes Alves ◽  
Peter Harley ◽  
José Francisco de C. Gonçalves ◽  
Carlos Eduardo da Silva Moura ◽  
Kolby Jardine
Keyword(s):  
Amazon Basin ◽  
Developmental Stages ◽  
Incident Light ◽  
Leaf Temperature ◽  
Mature Leaf ◽  
Senescent Leaf ◽  
Central Amazon ◽  
Isoprene Emission ◽  
Emission Models ◽  
Volatile Organic Compound Emissions

Isoprene emission from plants accounts for about one third of annual global volatile organic compound emissions. The largest source of isoprene for the global atmosphere is the Amazon Basin. This study aimed to identify and quantify the isoprene emission and photosynthesis at different levels of light intensity and leaf temperature, in three phenological phases (young mature leaf, old mature leaf and senescent leaf) of Eschweilera coriacea (Matamatá verdadeira), the species with the widest distribution in the central Amazon. In situ photosynthesis and isoprene emission measurements showed that young mature leaf had the highest rates at all light intensities and leaf temperatures. Additionally, it was observed that isoprene emission capacity (Es) changed considerably over different leaf ages. This suggests that aging leads to a reduction of both leaf photosynthetic activity and isoprene production and emission. The algorithm of Guenther et al. (1999) provided good fits to the data when incident light was varied, however differences among E S of all leaf ages influenced on quantic yield predicted by model. When leaf temperature was varied, algorithm prediction was not satisfactory for temperature higher than ~40 °C; this could be because our data did not show isoprene temperature optimum up to 45 °C. Our results are consistent with the hypothesis of the isoprene functional role in protecting plants from high temperatures and highlight the need to include leaf phenology effects in isoprene emission models.

Estimating mass of temperate and tropical pastures in the subtropics

1993 ◽  
Vol 33 (7) ◽  
pp. 865 ◽  
Author(s):  
WJ Fulkerson ◽  
K Slack
Keyword(s):  
Substantial Reduction ◽  
Ground Level ◽  
Regression Equations ◽  
Tropical Pastures ◽  
Senescent Leaf ◽  
Temperate Pastures ◽  
Second Year ◽  
Single Regression ◽  
Separate Regression ◽  
Subtropical Environment

The feasibility of estimating, with acceptable precision, temperate and tropical pasture mass in a subtropical environment was evaluated. For the tropical grasses kikuyu (Pennisetum clandestinum) and setaria (Setaria ancepts), 3 different pasture meters were calibrated against 1 of 3 dry matter (DM) estimates. Temperate pastures (predominantly Lolium perenne and Trifolium repens) were evaluated using the Ellinbank rising plate meter (RPMl) calibrated against DM to ground level. A single regression equation was developed for syegrass-white clover pasture from data pooled within season over first- and second-year swards. The s.e. of estimate (s.e.e.) for assessing tropical grass pasture mass using RPMl was similar to that for a heavier Ellinbank meter and substantially lower than that for the electronic pasture probe. Using RPMl, separate regression equations were required for early (November-February) and late (March-May) season determinations for both kikuyu and setaria. The regression equations were based on calibrations against shoot DM (>5 cm stubble height for kikuyu and 6 cm for setaria) and are only applicable to well-managed and highly utilised pastures. Calibrations of all pasture meters over all months to green DM (senescent leaf and stem removed) gave a lower s.e.e. than total DM (kikuyu 138 v. 177 kg DM/ha, n = 171; setaria 211 v. 224 kg DM/ha, n = 177) whilst shoot DM gave a more substantial reduction in s.e.e. (kikuyu 95 v. 147 kg DM/ha; setaria 140 v. 193 kg DM/ha).

scholarly journals New Tropical Fungi

Nature ◽  
1948 ◽  
Vol 162 (4110) ◽  
pp. 212-212
Keyword(s):  
Tropical Fungi

The decomposition of green leaf litter is less temperature sensitive than that of senescent leaf litter: An incubation study

Geoderma ◽  
2021 ◽  
Vol 381 ◽  
pp. 114691
Author(s):  
Renshan Li ◽  
Yanzhao Zhang ◽  
Dan Yu ◽  
Yu Wang ◽  
Xingxing Zhao ◽  
...  
Keyword(s):  
Leaf Litter ◽  
Green Leaf ◽  
Temperature Sensitive ◽  
Senescent Leaf ◽  
Incubation Study

DISTRIBUTION AND PATHOGENESIS OF DATE PALM FUNGI IN EGYPT

2007 ◽  
pp. 421-429 ◽  
Author(s):  
H.M. El-Deeb ◽  
S.M. Lashin ◽  
Y.A. Arab
Keyword(s):  
Date Palm ◽  
Palm Fungi

Effect of drought on morphological and functional traits of Poa ligularis and Pappostipa speciosa, native perennial grasses with wide distribution in Patagonian rangelands, Argentina

2013 ◽  
Vol 61 (5) ◽  
pp. 383 ◽  
Author(s):  
Ana M. Cenzano ◽  
M. Celeste Varela ◽  
Mónica B. Bertiller ◽  
M. Virginia Luna
Keyword(s):  
Functional Traits ◽  
Photosynthetic Pigments ◽  
Perennial Grass ◽  
Field Capacity ◽  
Dry Weight ◽  
Water Shortage ◽  
Perennial Grasses ◽  
Grass Species ◽  
Senescent Leaf ◽  
Poa Ligularis

Poa ligularis Nees. Ap. Steudel and Pappostipa speciosa (Trin. et Rupr.) Romaschenko are dominant perennial grasses in the arid Patagonian rangelands of Argentina. Both species are exposed to periods of water shortage during spring-summer and are grazed by domestic and native herbivores. Pappostipa speciosa displays xeromorphic adaptations and is less preferred by herbivores than P. ligularis. The knowledge of how drought affects morphological/functional traits in coexisting perennial grass species is useful to understanding the function of desert perennial grasses, and for the use and conservation of Patagonian arid rangelands. The hypothesis of this study was that co-existing perennial grasses contrasting in drought resistance mechanisms display different degrees of phenotypic plasticity in underlying and/or functional traits. Plants of both species were exposed to two levels of gravimetric soil moisture: 16% (~field capacity) and 4%. Plant vegetative and reproductive traits were measured weekly in individual plants and these were harvested at the end of the experiment. Aboveground and root biomass were separated in the harvested plants and the concentration of photosynthetic pigments was assessed in green leaves. The trait response range was also calculated through the plasticity index. In both species, drought stress led to significant reductions in plant height, total plant dry weight, number of total leaves, dry weight of green and senescent leaf, percentage of flowering plants, length of inflorescences, and number, length and dry weight of roots. The concentration of photosynthetic pigments increased under drought in both species. In conclusion, drought strongly affected reproductive and vegetative traits in both species and the greatest negative effect of drought was found in P. speciosa, the most conservative species. However, our findings might indicate that both species are able to maintain photosynthetic activity through the increase of photosynthetic pigments under drought conditions in Patagonian rangelands.

New Tropical Fungi

Mycologia ◽  
1927 ◽  
Vol 19 (5) ◽  
pp. 231 ◽  
Author(s):  
F. L. Stevens
Keyword(s):  
Tropical Fungi

scholarly journals senSCOPE: Modeling radiative transfer and biochemical processes in mixed canopies combining green and senescent leaves with SCOPE

2020 ◽  
Author(s):  
Javier Pacheco-Labrador ◽  
Tarek S. El-Madany ◽  
Christiaan van der Tol ◽  
M. Pilar Martin ◽  
Rosario Gonzalez-Cascon ◽  
...  
Keyword(s):  
Optical Properties ◽  
Radiative Transfer ◽  
Numerical Solutions ◽  
Gross Primary Production ◽  
Weighted Average ◽  
Senescent Leaf ◽  
Model Inversion ◽  
Scattering Coefficients ◽  
Thermal Signal ◽  
Parameters Inversion

AbstractSemi-arid grasslands and other ecosystems combine green and senescent leaves featuring different biochemical and optical properties, as well as functional traits. Knowing how these properties vary is necessary to understand the functioning of these ecosystems. However, differences between green and senescent leaves are not considered in recent models representing radiative transfer, heat, water and CO2 exchange such as the Soil-Canopy Observation of Photosynthesis and Energy fluxes (SCOPE). Neglecting the contribution of senescent leaves to the optical and thermal signal of vegetation limits the possibilities to use remote sensing information for studying these ecosystems; as well as neglecting their lack of photosynthetic activity increases uncertainty in the representation of ecosystem fluxes. In this manuscript we present senSCOPE as a step towards a more realistic representation of mixed green and senescent canopies. senSCOPE is a modified version of SCOPE model that describes a canopy combining green and senescent leaves with different properties and function. The model relies on the same numerical solutions than SCOPE, but exploits the linear nature of the scattering coefficients to combine optical properties of both types of leaf. Photosynthesis and transpiration only take place in green leaves; and different green and senescent leaf temperatures are used to close the energy balance. Radiative transfer of sun-induced fluorescence (SIF) and absorptance changes induced by the xanthophyll cycle action are also simulated. senSCOPE is evaluated against SCOPE both using synthetic simulations, forward simulations based on observations in a Mediterranean tree-grass ecosystem, and inverting dataset of ground measurements of reflectance factors, SIF, thermal radiance and gross primary production on a heterogeneous and partly senescent Mediterranean grassland. Results show that senSCOPE outputs vary quite linearly with the fraction of green leaf area, whereas SCOPE does not respond linearly to the effective leaf properties, calculated as the weighted average of green and senescent leaf parameters. Inversion results and pattern-oriented model evaluation show that senSCOPE improves the estimation of some parameters, especially chlorophyll content, with respect SCOPE retrievals during the dry season. Nonetheless, inaccurate knowledge of the optical properties of senescent matter still complicates model inversion. senSCOPE brings new opportunities for the monitoring of canopies mixing green and senescent leaves, and for improving the characterization of the optical properties of senescent material.

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