Use of aquatic plants by moose: sodium hunger or foraging efficiency?

1993 ◽  
Vol 71 (12) ◽  
pp. 2345-2351 ◽  
Author(s):  
James G. MacCracken ◽  
Victor Van Ballenberghe ◽  
James M. Peek

Use of submergent aquatic plants by North American moose (Alces alces) has been linked to sodium hunger. Habitat preferences, seasonal diets, forage abundance and quality, and population surveys indicated that emergent plants in small shallow ponds were important to moose on the Copper River Delta, Alaska. However, sodium was abundant in terrestrial browse. We propose that foraging in aquatic habitats, particularly on emergent species, may be highly efficient based on the following habitat attributes and behavioral observations: (i) ponds dominated by either emergent or submergent species produced about 4 times more forage than terrestrial habitats, (ii) emergent and submergent plants were more digestible and had higher concentrations of minerals than browse, (iii) use of aquatic habitats followed trends in forage production over the growing season, (iv) indirect evidence suggested that forage intake rates were greater in aquatic habitats, and (v) use of aquatic habitats by male and female moose was in proportion to the sex structure of the population. These data provide consistent circumstantial evidence that use of emergent species, and possibly submergents, may maximize the intake of nutrients and also reduce conflicts between cropping forage and vigilance during a foraging bout.

1994 ◽  
Vol 29 (4) ◽  
pp. 127-132 ◽  
Author(s):  
Naomi Rea ◽  
George G. Ganf

Experimental results demonstrate bow small differences in depth and water regime have a significant affect on the accumulation and allocation of nutrients and biomass. Because the performance of aquatic plants depends on these factors, an understanding of their influence is essential to ensure that systems function at their full potential. The responses differed for two emergent species, indicating that within this morphological category, optimal performance will fall at different locations across a depth or water regime gradient. The performance of one species was unaffected by growth in mixture, whereas the other performed better in deep water and worse in shallow.


Zootaxa ◽  
2009 ◽  
Vol 2027 (1) ◽  
pp. 43-54
Author(s):  
MATTHEW J. COLLOFF

Two new species of oribatid mite belonging to the genus Crotonia are described from tree trunks and their associated bryophytes in callidendrous rainforest, dominated by Nothofagus cunninghami, in Northeastern Tasmanian: C. tasmaniana sp. nov. and C. pyemaireneri sp. nov. Holonothrus ryszardi Łochyńska, 2008 is designated the junior subjective synonym of Crotonia ovata Olszanowski, 2000, and a supplementary description of the latter species is provided. The apparent arboreal habitat preferences of crotoniid mites are considered. In Tasmanian rainforest, the frequency of occurrence of these mites in moss on bark is higher than in terrestrial habitats, but not significantly so. High rainfall, a closed canopy, a low mean annual temperature and a consequent extensive corticolous and terricolous cover of bryophytes presents a continuum for these mites between ground and above-ground habitats.


2012 ◽  
Vol 518-523 ◽  
pp. 2597-2603
Author(s):  
Na He ◽  
Zhan Xiang Sun ◽  
Yu Long Zhang ◽  
Ming Da Liu

This study focused on the comparisons between nitrogen and phosphorus removal rates from the simulated wastewater using various kinds of aquatic plants (4 emergent and 3 floating plants). Results showed that aquatic plants has a significant effect on the removal of NO3--N and TP, but has a less effect on NH4+-N. Among the four emergent plants, the order of NO3--N removal capacities was: S. sagittifolia > S. tabernaemontani > T. latifolia > A. calamus. But for TP, the order was: T. latifolia > A. calamus > S. tabernaemontani > S. sagittifolia. To the floating plants, the order of NO3--N and TP removal capacities were: E. crassipes > P. stratiotes. The ANOVA analyses showed that there was a significant difference between planted treatments and unplanted treatment for the removal of NO3--N and TP. The study suggests that the treatment of simulated wastewater using the aquatic macrophytes was effective in the removal of nutrients.


2007 ◽  
Vol 274 (1620) ◽  
pp. 1885-1893 ◽  
Author(s):  
Torsten M Scheyer ◽  
P.Martin Sander

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti . Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, ‘aquatic’ turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record.


2007 ◽  
Vol 139 (4) ◽  
pp. 443-471 ◽  
Author(s):  
H. V. Danks

AbstractIn cold climates most aquatic habitats are frozen for many months. Nevertheless, even in such regions the conditions in different types of habitat, in different parts of one habitat, and from one year to the next can vary considerably; some water bodies even allow winter growth. Winter cold and ice provide challenges for aquatic insects, but so do high spring flows, short, cool summers, and unpredictable conditions. General adaptations to cope with these constraints, depending on species and habitat, include the use of widely available foods, increased food range, prolonged development (including development lasting more than one year per generation), programmed life cycles with diapause and other responses to environmental cues (often enforcing strict univoltinism), and staggered development. Winter conditions may be anticipated not only by diapause and related responses but also by movement for the winter to terrestrial habitats, to less severe aquatic habitats, or to different parts of the same habitat, and by construction of shelters. Winter itself is met by various types of cold hardiness, including tolerance of freezing in at least some species, especially chironomid midges, and supercooling even when surrounded by ice in others. Special cocoons provide protection in some species. A few species move during winter or resist anoxia beneath ice. Spring challenges of high flows and ice scour may be withstood or avoided by wintering in less severe habitats, penetrating the substrate, or delaying activity until after peak flow. However, where possible species emerge early in the spring to compensate for the shortness of the summer season, a trait enhanced (at least in some lentic habitats) by choosing overwintering sites that warm up first in spring. Relatively low summer temperatures are offset by development at low temperatures, by selection of warm habitats and microhabitats, and in adults by thermoregulation and modified mating activity. Notwithstanding the many abiotic constraints in cold climates, aquatic communities are relatively diverse, though dominated by taxa that combine traits such as cold adaptation with use of the habitats and foods that are most widely available and most favourable. Consequently, except in the most severe habitats, food chains and community structure are complex even at high latitudes and elevations, including many links between aquatic and terrestrial habitats. Despite the complex involvement of aquatic insects in these cold-climate ecosystems, we know relatively little about the physiological and biochemical basis of their cold hardiness and its relationship to habitat conditions, especially compared with information about terrestrial species from the same regions.


2017 ◽  
Vol 65 (3) ◽  
pp. 1095 ◽  
Author(s):  
Thainá Alves Lycarião ◽  
Ênio Wocyli Dantas

The aquatic plants and biological processes have different interactions and their knowledge may contribute to the understanding of environmental dynamics in wetlands. The aim of this study was to report the type of interactions that different biological forms of macrophytes stand in the eutrophic tropical reservoir of Penha reservoir, Northeastern Brazil. Data collection was captured every two months from October 2009 to October 2010, considering the hydrological cycle in one-year period. For this, twelve perpendicular transects (separated by 10 m) at the reservoir’s water edge were defined; each transect had two plots of 625 cm² (25 x 25 cm, separated by one meter) from which samples were obtained. Plants were collected and transported in identified plastic bags for subsequent quantification of the dry weight biomass; additionally, pressed samples were made in the field for identification purposes. The relative interaction index (RII) was used to identify the existence of positive and/or negative interactions between the biomass of the biological forms of aquatic plants. Student’s t-tests were used to analyze variations in the abiotic data and biomass over time, and to determine differences between the dry and rainy seasons. Pearson and Spearman correlation coefficients were calculated to determine correlations between the biological forms and the biomass of the macrophytes, as well as environmental variables and RII. In the dry season, the environment was mainly composed of floating macrophytes (1 013.98 g/m²), with mats of submerged macrophytes (98.18 g/m²) that demonstrated a range of positive (RII= 1.0) to negative (RII= -0.2) interactions. The biomass of emergent macrophytes increased throughout the dry season (4.87 to 106.91 g/m²) due to the nurse plant effect that served as a substratum (RII= 1.0). During the rainy season the biomass of submerged macrophytes was reduced by 97 % due to direct and indirect relationships (RII= -1.0) to other macrophytes. Rainfall and emergent plants contributed to a reduction in the biomass of floating macrophytes (19.16 g/m²). The emergence of a third group of plants (emergent) lead floating plants to occupy other areas and excluded submerged plants. Overall, the interactions among plants within ecosystems were not definite due to stand composition and seasonality.


Caldasia ◽  
2020 ◽  
Vol 42 (1) ◽  
pp. 115-128
Author(s):  
Esteban Terneus-Jácome ◽  
Berenice Vallejo-Solano ◽  
Mateo Gómez de la Torre ◽  
Christian Larenas-Uría

Aquatic plants are a priority biological group to study due to their high representativeness in ecosystem services and because they also indicate the state of conservation of lake systems. The goal of the study is to develop an Index of Macrophytes from continental Ecuador (IMAE), which can also be applied in the Andean region as a bioindicator, thus assessing the ecological health of the continental lakes and lagoons from 12 to 4000 m, evaluating the structure and floristic composition of aquatic plants and identifying the habitat preferences of the species according to the concentration of nutrients (nitrites, phosphates and ammonium), as determining elements of their presence. 104 species of aquatic plants were found. The tolerance and indicator values have been calculated for each species meanwhile seven levels of coverage were established. Last, four classes of trophic status or water quality were defined to asses lentic systems. The present study will significantly strengthen the environmental control tools for Ecuador.


1980 ◽  
Vol 11 (4) ◽  
pp. 369-392 ◽  
Author(s):  
N. Møller Andersen ◽  
John Polhemus

AbstractCryptovelia terrestris n. gen., n. sp. (Brazil), Darwinivelia fosteri n. gen., n. sp. (Galapagos Is.), Mniovelia kuscheli n. gen., n. sp. (New Zealand), and Cavaticovelia n. gen. (type-species: Speovelia aaa Gagné & Howarth, 1975; Hawaii) are described. The phylogenetic relationships between the mesoveliid genera are discussed in the light of characters revealed by the new taxa. Habitat preferences of mesoveliids include humid terrestrial and/or marginal aquatic habitats, which probably are the most ancestral, and lava-tubes, coastal caves, intertidal marine habitats, and the plant-covered freshwater surface, which probably are the derived kinds of habitats. A classification of the Mesoveliidae with a check list of genera and species is presented. Two subfamilies are recognized: Madeoveliinae (with two genera) and Mesoveliinae (seven genera). The biogeography of the Mesoveliidae is finally discussed.


ZooKeys ◽  
2019 ◽  
Vol 871 ◽  
pp. 89-118 ◽  
Author(s):  
Tolotra Ranarilalatiana ◽  
Johannes Bergsten

Diving beetles are generally aquatic and live submerged in water during larval and adult stages. A few groups have colonised hygropetric habitats and fewer species still can possibly be referred to as terrestrial. Here we describe six new Copelatine species that were mainly found in dry shallow forest floor depressions in the eastern and northeastern lowland humid forests of Madagascar. Three new species are described in each of the two genera Copelatus and Madaglymbus: Copelatus amphibiussp. nov., Copelatus betamponasp. nov., Copelatus zanatanensissp. nov., Madaglymbus kelimasosp. nov., Madaglymbus menalambasp. nov., and Madaglymbus semifactussp. nov. Diagnosis, description, known distribution, ecology, and conservation notes are provided for each species. All species are illustrated with a dorsal habitus image, ventral and lateral views of the male penis, and parameres. Photographs of the unusual terrestrial habitats where the species were found are provided. Madaglymbus menalambasp. nov. is also documented with macrophotos and videorecordings of the terrestrial locomotion and behaviour in the field. Although these species should not be classified as terrestrial, or even semi-terrestrial Dytiscidae, they seem to be specialists of very ephemeral aquatic habitats and stay put instead of disperse when the habitat dries up. It is hypothesised that this lifestyle and behaviour on Madagascar is restricted to the high-precipitation humid forest regions mainly in the east. It may also represent a transition step, or stepping-stone, towards becoming fully terrestrial, a step that the few known terrestrial Dytiscid taxa once passed through. It is very likely that this type of habitat is overlooked for aquatic beetles, not only in Madagascar, and the six species herein described may be just the “tip of the iceberg”.


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