Influence of dry season onQuercus suberL. leaf traits in the Iberian Peninsula

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

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Impact of Climate Change on Worlds Economy and Hydrological System

International Journal of Environment and Climate Change ◽

10.9734/ijecc/2021/v11i130342 ◽

2021 ◽

pp. 78-84

Author(s):

Sajid Ali ◽

Inayatullah Jan

Keyword(s):

Climate Change ◽

Ecosystem Services ◽

Global Change ◽

Iberian Peninsula ◽

Mediterranean Region ◽

Hydrological Model ◽

Dry Season ◽

Human Society ◽

Mediterranean River ◽

The Mediterranean

The Mediterranean region appears to be particularly responsive to global and climate change. The global mean temperature has increased by 0.8°C compared with preindustrial levels while Europe has warmed more than the global average, especially in the Mediterranean, the north-east region, and mountain areas. Increasingly drier conditions are observed in the Mediterranean region both in the wet and in the dry season (~20%) with an increasingly irregular precipitation in both seasons (~ 40% in the dry season). The annual river flows have also decreased in the Mediterranean region, a difference projected to exacerbate due to climate and global change, which made the Mediterranean region most prone to an increase in drought hazard and water stress. Iberian Peninsula has been already affected by several major droughts, e.g. the recent one in 2005. These driving forces of global change impacts on water availability, water quality, and ecosystem services in Mediterranean river basins of the Iberian Peninsula, as well as their impacts on the human society and economy, makes it an important issue on the EU agenda. This thesis is an approach to quantify and analyze the water quantity, hydrological ecosystem services, and water supply in temperate regions under environmental changes. A hydrological model is developed for a low flow Mediterranean river (Francolí River) to assess the water allocation situation in the river basin using MIKE BASIN. Since the Mediterranean regions are hard hit by the changes in the global climatic patterns, the hydrological model focuses on the water distribution system & flow in the region.

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Croton blanchetianus modulates its morphophysiological responses to tolerate drought in a tropical dry forest

Functional Plant Biology ◽

10.1071/fp17098 ◽

2017 ◽

Vol 44 (10) ◽

pp. 1039 ◽

Cited By ~ 7

Author(s):

Keila R. Mendes ◽

João A. A. Granja ◽

Jean P. Ometto ◽

Antônio C. D. Antonino ◽

Rômulo S. C. Menezes ◽

...

Keyword(s):

Rainy Season ◽

Tropical Dry Forest ◽

Net Photosynthesis ◽

Leaf Traits ◽

Co2 Assimilation ◽

Dry Season ◽

Dry Forest ◽

Light Conditions ◽

Dry Tropical Forests ◽

Use Efficiency

An understanding of variations in morphophysiological leaf traits of plant models in dry tropical forests is essential for quantifying C fluxes from forest ecosystems in response to climate changes. The present study evaluated the influences of seasonal rainfall and different light conditions on the gas exchange, nutrients, organic compounds and morphological traits in Croton blanchetianus Baill. trees within a fragment of Caatinga forest. Stomatal conductance (gs) and net photosynthesis (PN) demonstrated variations within the diurnal cycle, with maximum values at approximately midday and minimum values at predawn. The PN and the diurnal integrated CO2 assimilation were lower during the dry season than in the rainy season. Water use efficiency was positively correlated with PN (r = 0.73) during the dry season only. However, the correlation between PN and gs was observed during the rainy season only (r = 0.60). Thus we demonstrated that C. blanchetianus has a remarkable ability to adapt to global climatic changes and could be considered a model in studies exploring water relationships in woody plants; consequently, this species may be important in future reforestation studies.

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Does leaf flushing in the dry season affect leaf traits and herbivory in a tropical dry forest?

The Science of Nature ◽

10.1007/s00114-020-01711-z ◽

2020 ◽

Vol 107 (6) ◽

Author(s):

Jhonathan O. Silva ◽

Mário M. Espírito-Santo ◽

Joselândio C. Santos ◽

Priscyla M. S. Rodrigues

Keyword(s):

Tropical Dry Forest ◽

Leaf Traits ◽

Dry Season ◽

Dry Forest ◽

Leaf Flushing

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River Mangrove Maintains Certain Level Na+ and Cl- in Leaves to Adapt Seasonal Freshwater

10.21203/rs.3.rs-669591/v1 ◽

2021 ◽

Author(s):

Li Xu ◽

Chao Liu ◽

Changpeng Xin ◽

Wenqing Wang

Keyword(s):

Leaf Traits ◽

Dry Season ◽

Wet Season ◽

Upstream Site ◽

Aegiceras Corniculatum ◽

Photosystem Ii Efficiency ◽

Low Salinity ◽

Stressful Environment ◽

Quenching Analysis ◽

Freshwater Habitats

Abstract Background: Mangrove environments are often characterized by large fluctuations in salinity, ranging from freshwater to hypersaline conditions. Most reports have focused on the mechanisms by which mangroves adapt to high salinity. However, how mangroves cope with seasonal freshwater habitats has seldom been studied. To address this question, we surveyed the river salinity and leaf traits (chlorophyll fluorescence, ion concentrations, carbon isotope ratios and osmolality) of Aegiceras corniculatum (L.) Blanco (river mangrove) along a freshwater-dominated river.Results: Aegiceras corniculatum at the upstream site was subjected to low salinity, being in fresh water for a long period (up to 310 h) in the wet season and experiencing a short term of low salinity in the dry season. The actual photosystem II efficiency (ФPSII) and electron transport rates (ETR) of the leaves at the upstream site decreased in the wet season, and recovered substantially in the dry season. Quenching analysis indicated that there was only a down-regulation of photoprotection, but no photoinhibition at the upstream site in the wet season. An explanation for this is that high levels of Na+ and Cl- were maintained in the leaves in the wet season.Conclusions: Long-term freshwater is a stressful environment for A. corniculatum. Aegiceras corniculatum maintains certain level Na+ and Cl- to adapt the seasonal freshwater.

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