scholarly journals Differential Effects of Lichens versus Liverworts Epiphylls on Host Leaf Traits in the Tropical Montane Rainforest, Hainan Island, China

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Lingyan Zhou ◽  
Fude Liu ◽  
Wenjie Yang ◽  
Hong Liu ◽  
Hongbo Shao ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Host Plants ◽  
Leaf Surface ◽  
Hainan Island ◽  
Leaf Traits ◽  
Leaf Water Content ◽  
Negative Effects ◽  
Saturation Point ◽  
Chl A ◽  
Light Saturation Point

Epiphylls widely colonize vascular leaves in moist tropical forests. Understanding the effects of epiphylls on leaf traits of host plants is critical for understanding ecological function of epiphylls. A study was conducted in a rain forest to investigate leaf traits of the host plantsPhotinia prunifoliacolonized with epiphyllous liverworts and foliicolous lichens as well as those of uncolonized leaves. Our results found that the colonization of lichens significantly decreased leaf water content (LWC), chlorophyll (Chl) a and a + b content, and Chl a/b ofP. prunifoliabut increased Chl b content, while that of liverworts did not affect them as a whole. The variations of net photosynthetic rates(Pn)among host leaves colonized with different coverage of lichens before or after removal treatment (a treatment to remove epiphylls from leaf surface) were greater than that colonized with liverworts. The full cover of lichens induced an increase of light compensation point (LCP) by 21% and a decrease of light saturation point (LSP) by 54% for their host leaves, whereas that of liverworts displayed contrary effects. Compared with the colonization of liverworts, lichens exhibited more negative effects on the leaf traits ofP. prunifoliain different stages of colonization. The results suggest that the responses of host leaf traits to epiphylls are affected by the epiphyllous groups and coverage, which are also crucial factors in assessing ecofunctions of epiphylls in tropical forests.

TUNGAU PADA DAUN MANGGA (Mangifera Indica)

2014 ◽  
Vol 13 (3) ◽  
Author(s):  
Rawati Panjaitan
Keyword(s):  
Life Cycle ◽  
Direct Observation ◽  
Host Plants ◽  
Body Shape ◽  
Leaf Surface ◽  
Mangifera Indica ◽  
Posterior Part ◽  
Mango Leaves

Mites have hostplant specifications or host plants. Mites can be destructive and deadly of which is the host plants a mango crop. Mites on mango crops will cause the leaves yellow and fall off prematurely. This is will lead to the disruption of the productivity of mango. It is necessary for research to identify the mites that infect the mango crop. The method is carried out by direct observation. Mites were taken from the surface of mango leaves later in preservation with several levels of concentration of alcohol, and polyvinyl laktofenol. Then, observed under a microscope and documented for identification purposes. Mites on the leaf surface of manalagi mango (<em>Mangifera indica</em>) found two species, it is <em>Oligonychus</em> sp. and <em>Oligonychus ilicis</em> (Family: Tetranychidae, Superfamily: Tetranychoidea). <em>Oligonychus</em> sp. hallmark is rounded body shape like a spider, with a body is transparent and there are two long seta on posterior part. While <em>Oligonychus ilicis</em> has a characteristic elongated rounded body shape, red, and there is a short posterior seta. <em>Oligonychus</em> sp. and <em>Oligonychus ilicis</em> live as parasites on the surface of mango leaves that can lead to wrinkled leaves, yellow and to fall. <em>Oligonychus</em> life cycle starts from the eggs develop into Nympha and then adult.

Leaf traits influencing oviposition preference and larval performance ofCameraria ohridellaon native and novel host plants

2014 ◽  
Vol 152 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Lilla D'Costa ◽  
Monique S.J. Simmonds ◽  
Nigel Straw ◽  
Bastien Castagneyrol ◽  
Julia Koricheva
Keyword(s):  
Host Plants ◽  
Oviposition Preference ◽  
Leaf Traits ◽  
Larval Performance ◽  
Novel Host

scholarly journals Earth observation for monitoring and mapping of cyanobacteria blooms. Case studies on five Italian lakes

2016 ◽  
Vol 76 (s1) ◽  
Author(s):  
Mariano Bresciani ◽  
Claudia Giardino ◽  
Rosaria Lauceri ◽  
Erica Matta ◽  
Ilaria Cazzaniga ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Algal Blooms ◽  
Remote Sensing Data ◽  
Late Summer ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Landsat 8 ◽  
Negative Effects ◽  
Eutrophic Lakes ◽  
Chl A

Cyanobacterial blooms occur in many parts of the world as a result of entirely natural causes or human activity. Due to their negative effects on water resources, efforts are made to monitor cyanobacteria dynamics. This study discusses the contribution of remote sensing methods for mapping cyanobacterial blooms in lakes in northern Italy. Semi-empirical approaches were used to flag scum and cyanobacteria and spectral inversion of bio-optical models was adopted to retrieve chlorophyll-a (Chl-a) concentrations. Landsat-8 OLI data provided us both the spatial distribution of Chl-a concentrations in a small eutrophic lake and the patchy distribution of scum in Lake Como. ENVISAT MERIS time series collected from 2003 to 2011 enabled the identification of dates when cyanobacterial blooms affected water quality in three small meso-eutrophic lakes in the same region. On average, algal blooms occurred in the three lakes for about 5 days a year, typically in late summer and early autumn. A suite of hyperspectral sensors on air- and space-borne platforms was used to map Chl-a concentrations in the productive waters of the Mantua lakes, finding values in the range of 20 to 100 mgm-3. The present findings were obtained by applying state of the art of methods applied to remote sensing data. Further research will focus on improving the accuracy of cyanobacteria mapping and adapting the algorithms to the new-generation of satellite sensors.

scholarly journals Photosynthetic Characteristics of Four Wild Dendrobium Species in China

HortScience ◽  
2014 ◽  
Vol 49 (8) ◽  
pp. 1023-1027
Author(s):  
Gang-Yi Wu ◽  
Jun-Ai Hui ◽  
Zai-Hua Wang ◽  
Jie Li ◽  
Qing-Sheng Ye
Keyword(s):  
Glycolate Oxidase ◽  
Photosynthetic Pathway ◽  
Light Saturation ◽  
Saturation Point ◽  
Apparent Quantum Yield ◽  
Bisphosphate Carboxylase ◽  
Photosynthetic Physiology ◽  
Light Saturation Point ◽  
Second Peak ◽  
Dendrobium Densiflorum

Photosynthetic physiology of Dendrobium nobile, Dendrobium pendulum, Dendrobium chrysotoxum, and Dendrobium densiflorum was studied. A bimodal diurnal variation of the net photosynthetic rate (Pn) was observed in the four Dendrobium species with the first peak [5.09 to 6.06 μmol (CO2) per m−2·s−1] ≈1100 hr and the second peak [3.83 to 4.58 μmol (CO2) per m−2·s−1] at 1500 hr. No CO2 fixation was observed at night. For all four Dendrobium species, the light compensation point (LCP) was 5 to 10 μmol·m−2·s−1, light saturation point (LSP) ranged from 800 to 1000 μmol·m−2·s−1, apparent quantum yield (AQY) was 0.02, and CO2 compensation points (CCP) and saturation point (CSP) were 60 to 85 μmol·mol−1 and 800 to 1000 μmol·mol−1, respectively. Carboxylation efficiency (CE) values ranged from 0.011 to 0.020. The optimum temperature for photosynthesis was between 26 and 30 °C. The measurement of Pn seasonal variation indicated that July to August had the higher Pn for Dendrobium species. Additionally, the chlorophyll a/b (Chl a/b) ratios of the leaves were 2.77 to 2.89. Measurement of key enzymes in the photosynthetic pathway indicated relatively high Ribulose-1,5-bisphosphate carboxylase (RuBPCase) and glycolate oxidase (GO) activities but very low phosphoenolpyruvate carboxylase (PEPCase) activities. It suggested that these four Dendrobium species are typical semishade C3 plants.

scholarly journals Relationships between Foliar Fungal Endophyte Communities and Ecophysiological Traits of CAM and C3 Epiphytic Bromeliads in a Neotropical Rainforest

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 378 ◽  
Author(s):  
Peter H. Tellez ◽  
Carrie L. Woods ◽  
Stephen Formel ◽  
Sunshine A. Van Bael
Keyword(s):  
Fungal Endophytes ◽  
Leaf Traits ◽  
Fungal Endophyte ◽  
Leaf Water Content ◽  
Leaf Toughness ◽  
Vascular Epiphytes ◽  
Ecophysiological Traits ◽  
Photosynthetic Pathways ◽  
Relative Abundances ◽  
Epiphytic Bromeliads

Vascular epiphytes contribute up to 35% of the plant diversity and foliar biomass of flowering plants. The family Bromeliaceae is a monophyletic group of plants native to the Neotropics. Epiphytic bromeliads form associations with distinct groups of organisms but their relationship with foliar fungal endophytes remain underexplored. In this study we examined the relationship of foliar fungal endophytes to host photosynthetic pathways and associated ecophysiological traits. We sampled the fungal endophyte communities of 67 host individuals in six epiphytic bromeliad species differing in C3 and crassulacean acid metabolism (CAM) photosynthetic pathways. We tested whether endophyte assemblages were associated with ecophysiological leaf traits related to host photosynthetic pathways. Our results indicate that (1) C3 and CAM bromeliads host dissimilar endophyte assemblages, (2) endophyte communities in C3 bromeliads are characterized by variable relative abundances of fungal orders; conversely, CAM associated endophyte communities were characterized by consistent relative abundances of fungal orders, and (3) endophyte communities in bromeliads are distributed along a continuum of leaf toughness and leaf water content. Taken together, our study suggests that host physiology and associated ecophysiological traits of epiphytic bromeliads may represent biotic filters for communities of fungal endophytes in the tropics.

scholarly journals Photosynthesis sensitivity to NH4+-N change with nitrogen fertilizer type

2014 ◽  
Vol 60 (No. 6) ◽  
pp. 274-279 ◽  
Author(s):  
A. Nasraoui-Hajaji ◽  
H. Gouia
Keyword(s):  
Net Photosynthesis ◽  
Dry Weight ◽  
N Fertilization ◽  
Photochemical Quenching ◽  
Negative Effects ◽  
Ps Ii ◽  
Chl A ◽  
Inhibitory Site ◽  
Tomato Growth ◽  
Non Photochemical Quenching

N-fertilization type affected differently tomato growth. In the field experiment, hydroponic cultures were conducted using NO<sub>3</sub>-N (5 mmol); mixture of KNO<sub>3</sub>-N (3 mmol) and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>-N (2 mmol); NH<sub>4</sub><sup>+</sup>-N (5 mmol) or urea&nbsp;(5 mmol) as nitrogen source. Compared to nitrate, ammonium and urea had negative effects on morphology and dry matter production. Effects of the different nitrogen forms were investigated by measuring several photosynthesis parameters and chl a fluorescence. Two different significant types of reaction were found. When nitrogen was added as ammonium or urea, dry weight, chlorophyll tenor, transpiration rate, stomatal conductance and photosynthetic activity were inhibited. Supply of ammonium or urea, reduced the ratio (F<sub>v</sub>/F<sub>m</sub>), photochemical quenching and enhanced the non photochemical quenching. These data suggest that the adverse decrease in tomato growth under ammonium or urea supply may be related principally to inhibition of net photosynthesis activity. The high non photochemical quenching shown in tomato fed with ammonium or urea indicated that PS II was the inhibitory site of NH<sub>4</sub><sup>+</sup>-N which was directly uptaken by roots, or librated via urea hydrolysis cycle.

scholarly journals Severe Water Deficiency during the Mid-Vegetative and Reproductive Phase has Little Effect on Proso Millet Performance

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2155 ◽  
Author(s):  
Grašič ◽  
Golob ◽  
Vogel-Mikuš ◽  
Gaberščik
Keyword(s):  
Crop Production ◽  
Plant Biomass ◽  
Leaf Traits ◽  
Water Shortage ◽  
Short Wave ◽  
Leaf Biomass ◽  
Yield Reduction ◽  
Water Deficiency ◽  
Negative Effects ◽  
Proso Millet

Climate change can result in extreme droughts, significantly affecting crop production. C4 crop proso millet (Panicum miliaceum L.) has the lowest water consumption among all of the cereal crops. Understanding its survival mechanisms is thus crucial for agriculture. Furthermore, yield reduction does not only occur directly due to water shortage, but is also a consequence of an impaired element uptake during drought. This study aimed to examine the effect of water deficiency on proso millet leaf traits, plant biomass partition, and yield. In addition, leaf element contents were analysed, including silicon, which is an important multifunctional element for grasses. The majority of the measured parameters showed little change from the control to the moderate and severe water shortage treatments, even though the soil moisture levels differed significantly. The most pronounced reduction in comparison to the control was for leaf biomass, leaf stomatal conductance, and leaf silicon, phosphorus, calcium, and sulphur contents. Conversely, an increase was obtained for leaf potassium and chlorine contents. Panicle biomass was the same for all plant groups. Leaf silicon was positively correlated to reflectance in the UV region, while leaf calcium was negatively correlated to reflectance in the visible regions, which might prevent damage due to short-wave UV radiation and provide sufficient visible light for photosynthesis. The efficient light and water management, reduction of leaf biomass, and same-sized root system may be the mechanisms that mitigate the negative effects of water shortage in proso millet.

scholarly journals Correction to: Morphological variation of fine root systems and leaves in primary and secondary tropical forests of Hainan Island, China

2020 ◽  
Vol 77 (4) ◽  
Author(s):  
J. Aaron Hogan ◽  
Oscar J. Valverde-Barrantes ◽  
Qiong Ding ◽  
Han Xu ◽  
Christopher Baraloto
Keyword(s):  
Tropical Forests ◽  
Morphological Variation ◽  
Fine Root ◽  
Hainan Island ◽  
Root Systems

Leaf physiological response to light environment of three tree fern species in a Mexican cloud forest

2013 ◽  
Vol 29 (3) ◽  
pp. 217-228 ◽  
Author(s):  
K. Riaño ◽  
O. Briones
Keyword(s):  
Quantum Yield ◽  
Cloud Forest ◽  
Leaf Traits ◽  
Light Sensitivity ◽  
Canopy Openness ◽  
Tree Fern ◽  
Interspecific Differences ◽  
Open Canopy ◽  
Fern Species ◽  
Light Saturation Point

Abstract:Abundance and physiology of three understorey tree fern species were compared in a Mexican cloud forest. We hypothesized that the distribution of species would be associated with canopy openness and leaf physiological characteristics. In gullies (1–2% full sun), Alsophila firma was abundant, Cyathea divergens was distributed in moderately open places (4–9%), and Lophosoria quadripinnata preferred more open canopy (9–30%). Although 11 leaf traits of five plants of each species growing under closed and open canopies over 1 y did not differ within species, there were significant interspecific differences. Alsophila firma had comparatively low maximum electron transport rate ETRmax (26.8 ± 1.81 μmol m−2 s−1) and ETR light saturation point (ETRLSP: 261 ± 36.1 μmol m−2 s−1), high specific leaf area (SLA), thin leaves and decreased quantum yield during a leaf desiccation experiment. Cyathea divergens had relatively high maximum quantum yield (0.84 ± 0.004), ETRmax (37.3 ± 1.8 μmol m−2 s−1) and ETRLSP (409 ± 40.0 μmol m−2 s−1). Lophosoria quadripinnata had comparatively thick leaves, low SLA, high predawn water potential, high density (606 ± 25.5 mm−2) and small length (0.026 ± 0.002 mm) stomata. The results support the hypothesis that light sensitivity shapes tree fern distribution in the cloud forest.

The Photosynthetic Characteristics of Moso Bamboo (Phyllostachys pubescens) for Different Canopy Leaves

2013 ◽  
Vol 726-731 ◽  
pp. 4274-4279
Author(s):  
Yong Hui Cao ◽  
Ben Zhi Zhou ◽  
Xiao Ming Wang ◽  
Gang Wang
Keyword(s):  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Lower Layer ◽  
Middle Layer ◽  
B Value ◽  
Phyllostachys Pubescens ◽  
Light Saturation ◽  
Saturation Point ◽  
Low Light ◽  
Light Saturation Point

The carbon sequestration ability of different ages of Phyllostachys pubescens was analyzed at three canopy layers with a LI-6400 portable photosynthesis system. Under different photosynthetically active radiation (PAR), the net photosynthetic rate (Pn) of upper and middle layers of 3-year old bamboo were significantly higher than that of lower layer. When the light was greater than 800 umol·m-2·s-1, the Pn of bamboo in middle layer was in the order of 3-year-old > 4-year- old >2-year-old >7-year-old bamboo. When the light was greater than 500 umol·m-2·s-1, Pn of lower layer was in the order of 3-year old > 4-year old >2-year old, while in the order of 3-year-old > 2-year -old >4-year-old bamboo during the low light range (PAR<200 umol·m-2·s-1).The chlorophyll a/b value, maximum net photosynthetic rate, light compensation point and light saturation point values change were reduced gradually with the decrease of canopy height.

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