Terrestrial burrowing ecology of newly metamorphosed frogs (Rana pipiens complex)

1998 ◽  
Vol 76 (11) ◽  
pp. 2124-2129 ◽  
Author(s):  
Matthew J Parris

I examined the burrowing performance of newly metamorphosed Rana areolata, Rana blairi, and Rana sphenocephala in laboratory aquaria. Three treatments were used to determine whether metamorphs, when deprived of a water source, actively dig their own burrows, and if they utilize natural irregularities in substrate profiles or preexisting burrows as shelter from evaporative desiccation. Analysis of covariance (initial body mass covariate) revealed that individuals of all three species actively burrowed and passively utilized preexisting experimental burrows, but active burrowing, which consisted of substrate excavation using only the hind limbs, took much longer. Metamorphs that used preexisting burrows conserved water more efficiently than those that actively dug their own burrows. Rana blairi experienced the highest percent water loss across all treatments and was the only species to suffer mortality during the experiment. These data suggest that burrowing, by minimizing evaporative water loss, may be a critical adaptive behavior for metamorphic frogs in semi-arid environments.

2004 ◽  
Vol 82 (8) ◽  
pp. 1326-1335 ◽  
Author(s):  
Martim de França Silveira Ribeiro ◽  
Pedro Luiz Bernardo da Rocha ◽  
Lys Angela Favaroni Mendes ◽  
Steven Franklin Perry ◽  
Elisabeth Spinelli de Oliveira

Ancestrally, oryzomyine rodents have a sylvan habit, but some species have colonized the semi-arid Brazilian Caatinga. Therefore, the clade provides a suitable model for studying adaptation to such environments within a phylogenetic framework. We investigated physiological responses to short-term water deprivation in two oryzomyine rodents kept in captivity. Oligoryzomys nigripes (Olfers, 1818), a small-bodied rodent, occupies the Caatinga, whereas Nectomys squamipes (Brants, 1827), which is larger and semi-aquatic, lives in moist habitats outside this region. Measurements were also carried out in three additional related species of intermediate body size. Neither O. nigripes nor N. squamipes displays exceptional ability to conserve water, and this condition appears to be plesiomorphic for the clade. The results for O. nigripes, such as the great absolute water intake and the high ratio of water ingested to urine voided, probably derive from allometric specializations correlated with its small body size and greater evaporative water loss. In N. squamipes, low urine osmolality and a reduction of food intake during water deprivation may be related to its semi-aquatic lifestyle. Therefore, the Oryzomyini exemplify Neotropical rodents that can occupy semi-arid environments with no remarkable physiological adaptation for water conservation.


The Auk ◽  
2019 ◽  
Vol 137 (1) ◽  
Author(s):  
Soorim Song ◽  
Steven R Beissinger

Abstract Endotherms dissipate heat to the environment to maintain a stable body temperature at high ambient temperatures, which requires them to maintain a balance between heat dissipation and water conservation. Birds are relatively small, contain a large amount of metabolically expensive tissue, and are mostly diurnal, making them susceptible to physiological challenges related to water balance and heat dissipation. We compiled total evaporative water loss (TEWL) measurements for 174 species of birds exposed to different temperatures and used comparative methods to examine their relationships with body size, ambient temperature, precipitation, diet, and diel activity cycle. TEWL in the thermoneutral zone (TNZ) was associated primarily with body mass and activity phase. Larger and more active-phase birds, with their higher metabolic rates, lost more water through evaporation than smaller, resting-phase birds, particularly at higher thermal exposures. However, maximum temperature of the natural habitat became an important determinant of TEWL when birds were exposed to temperatures exceeding the TNZ. Species from hotter climates exhibited higher TEWL. Adaptation to arid climates did not restrict evaporative water loss at thermal conditions within the TNZ, but promoted evaporative water loss at exposures above the TNZ. The TEWL of granivores, which ingest food with low water content, differed little from species with other food habitats under all thermal conditions. The effects of environmental covariates of TEWL were dissimilar across thermal exposures, suggesting no evidence for a tradeoff between water conservation in the TNZ and heat dissipation at exposure to higher temperatures. Thus, birds may be able to acclimate when climate change results in the need to increase heat dissipation due to warming, except perhaps in hot, arid environments where species will need to depend heavily upon evaporative cooling to maintain homeothermy.


2019 ◽  
Author(s):  
Juan M. Losada ◽  
Miriam Díaz ◽  
N. Michele Holbrook

ABSTRACTCapparis odoratissima is a tree species native to semi-arid environments of the northern coast of South America where low soil water availability coexists with frequent nighttime fog. Previous work with this species demonstrated that C. odoratissima is able to use water absorbed through its leaves at night to enhance leaf hydration, photosynthesis, and growth.Here, we combine detailed anatomical evaluations of the leaves of C. odoratissima, with water and dye uptake experiments in the laboratory. We used immunolocalization of pectin and arabinogalactan protein epitopes to characterize the chemistry of foliar water uptake pathways.The abaxial surfaces of C. odoratissima leaves are covered with overlapping, multicellular peltate hairs, while the adaxial surfaces are glabrous but with star-shaped “structures” at regular intervals. Despite these differences in anatomy, both surfaces are able to absorb condensed water, but this ability is most significant on the upper surface. Rates of evaporative water loss from the upper surface, however, are coincident with cuticle conductance. Numerous idioblasts connect the adaxial leaf surface and the adaxial peltate hairs, which contain hygroscopic substances such as arabinogalactan proteins and pectins.The highly specialized anatomy of the leaves of C odoratissima fulfills the dual function of avoiding excessive water loss due to evaporation, while maintaining the ability to absorb liquid water. Cell-wall related hygroscopic compounds present in the peltate hairs and idioblasts create a network of microchannels that maintain leaf hydration and promote the uptake of aerial water.


1965 ◽  
Vol 13 (2) ◽  
pp. 317 ◽  
Author(s):  
MR Warburg

The rate of evaporative water loss of several species of frog found in Australia and their ability to survive at high temperatures were studied at various temperatures in both dry and in humid air, and at constant vapour pressure deficit. The species studied were: Bufonidae, Bufo marinus (L.); Leptodactylidae, Crinia signifera Girard, Pseudophryne bibroni Gunther, Limnodynastes tasmaniensis Gunther, L. dorsalis (Gray), L. ornatus (Gray), Neobatrachus pictus Peters, N. centralis (Parker); Hylidae, Hyla ewingi (Dumeril & Bibron) and H. rubella Gray. To a certain extent, the trend for increased adaptation to terrestrial conditions follows the trend for reduced water loss. The rate of water uptake after dehydration is greatest in the burrowing frogs inhabiting arid and semi-arid regions. Survival at high temperatures in dry air was found to be a good criterion for judging the degree of adaptation of these frogs to life in arid regions.


2020 ◽  
Author(s):  
Andreas Kallioras ◽  
Efthymios Chrysanthopoulos ◽  
Anastasios Mitropapas ◽  
Epaminondas Floros ◽  
Sofia Nalbadi ◽  
...  

<p>Groundwater is a limited resource in coastal hydrogeological systems, especially in semi-arid environments where the irrigation demands are very high. Management of such hydrosystems is a very challenging process; while water conflict between different users as well as climate change conditions are magnifying this problem.</p><p>Managed aquifer recharge – storing water in aquifers during times of excess – is considered as a sound engineering technique and a key strategy to support groundwater resources in such hydrologically sensitive regions by providing intermediate storage, bridging the gap between water demand and availability. In addition to the above, innovative modelling techniques that apply participatory approaches can be proved a valuable supporting tool for the management of groundwater resources within an optimized manner.</p><p>The coastal field of Argolis (S. Greece) is used as a reference site to illustrate the above, where Managed Aquifer Recharge is applied on a full-scale mode since 1990, using karst groundwater as a recharge water source. The study area involves an extended and complex water infrastructure systems that includes: (a) a main intake structure -a submarine dam exploiting a system of submarine karstic springs-; (b) a conveyance system -mainly open canal structures- that assures the transport of water from the main intake structure and main pumping station up to the agricultural area; and (c) a cluster of Managed Aquifer Recharge facilities that divert water towards the subsurface either through deep groundwater wells or infiltration ponds at selected parts of the aquifer.     </p><p>This research presents the results of hydro‐environmental modelling activities of Managed Aquifer Recharge and the preliminary work on participatory driven water resources modelling scenarios. This study is envisaged to contribute in the identification and valuation of socio‐economic and environmental processes and linkages of groundwater uses and services.</p>


1999 ◽  
Vol 40 (4-5) ◽  
pp. 43-50 ◽  
Author(s):  
Marcelo Juanico ◽  
Eran Friedler

Most of the water has been captured in the rivers of Israel and they have turned into dry river-beds which deliver only sporadic winter floods. In a semi-arid country where literally every drop of water is used, reclaimed wastewater is the most feasible water source for river recovery. Two topics are addressed in this paper: water quality management in rivers where most of the flowing water is treated wastewater, and the allocations of reclaimed wastewater required for the recovery of rivers and streams. Water quality management must consider that the main source of water to the river has a pollution loading which reduces its capability to absorb other pollution impacts. The allocation of treated wastewater for the revival of rivers may not affect negatively the water balance of the region; it may eventually improve it. An upstream bruto allocation of 122 MCM/year of wastewater for the recovery of 14 rivers in Israel may favor downstream reuse of this wastewater, resulting in a small neto allocation and in an increase of the water resources available to the country. The discharge of effluents upstream to revive the river followed by their re-capture downstream for irrigation, implies a further stage in the intensification of water reuse.


Author(s):  
Cristian Epifanio Toledo ◽  
João Carlos Mohn Nogueira ◽  
Alexandre De Amorim Camargo

The objective of this work was to propose and evaluate a model to estimate transit water losses and surface runoff in a Brazilian semi-arid basin, fundamental components in the hydrological studies of the region, such as in the verification of hydrological connectivity. The study area was the Orós Reservoir Basin, located in the state of Ceará. The modeling of transit water loss and surface runoff were developed based on the work of Araújo and Ribeiro (1996) and Peter et al. (2014). In the proposed model, the parameter of loss in transit (k) was estimated at 0.027 km-1 for a section of the river basin, and when simulated for other stretches it provided good flow results at the end of the stretch, obtaining an NSE of 82%. The value of the runoff coefficient was estimated at 3% and when evaluating a spatial variation of this coefficient in the basin, the values varied from 2% to 12%, and the use of specialized runoff coefficient (RC) values promoted a higher NSE in the discharge simulation in the basin. It is concluded that the proposed model to estimate transit water losses and surface runoff demonstrated a high efficiency in the simulation of hydrological processes. The basin of Orós reservoir presented a high variability of the coefficient of surface runoff, justifying the need for a greater spatiality of this coefficient in heterogeneous environments.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 354
Author(s):  
El-Sayed M. Desoky ◽  
Elsayed Mansour ◽  
Mohamed M. A. Ali ◽  
Mohamed A. T. Yasin ◽  
Mohamed I. E. Abdul-Hamid ◽  
...  

The influence of 24-epibrassinolide (EBR24), applied to leaves at a concentration of 5 μM, on plant physio-biochemistry and its reflection on crop water productivity (CWP) and other agronomic traits of six maize hybrids was field-evaluated under semi-arid conditions. Two levels of irrigation water deficiency (IWD) (moderate and severe droughts; 6000 and 3000 m3 water ha−1, respectively) were applied versus a control (well-watering; 9000 m3 water ha−1). IWD reduced the relative water content, membrane stability index, photosynthetic efficiency, stomatal conductance, and rates of transpiration and net photosynthesis. Conversely, antioxidant enzyme activities and osmolyte contents were significantly increased as a result of the increased malondialdehyde content and electrolyte leakage compared to the control. These negative influences of IWD led to a reduction in CWP and grain yield-related traits. However, EBR24 detoxified the IWD stress effects and enhanced all the above-mentioned parameters. The evaluated hybrids varied in drought tolerance; Giza-168 was the best under moderate drought, while Fine-276 was the best under severe drought. Under IWD, certain physiological traits exhibited a highly positive association with yield and yield-contributing traits or CWP. Thus, exogenously using EBR24 for these hybrids could be an effective approach to improve plant and water productivity under reduced available water in semi-arid environments.


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