Seasonal changes in the diet of the European rabbit (Oryctolagus cuniculus) from three different Mediterranean habitats in south-western Australia

2007 ◽  
Vol 34 (1) ◽  
pp. 25 ◽  
Author(s):  
Gary R. Martin ◽  
Laurie E. Twigg ◽  
Lina Zampichelli

Abstract.�Seasonal changes in the diet of rabbits from three temperate (Mediterranean) areas in south-western Australia were identified using microscopic determination of the percentage occurrence of various food groups in sampled stomachs. The sites differed in soil type and in the availability of summer perennials, native vegetation bush remnants (size of, and number of plant species), improved pastures, and summer rainfall, and hence, enabled a comparison of the diet of rabbits from the different vegetation communities. Although the diet of these rabbits was quite flexible, with some switching in food items occurring between seasons, there were marked differences in the proportion of monocotyledonous and dicotyledonous species eaten in each habitat. There was a strong reliance on seeds (1-5 species) during late spring and summer in all three habitats. Guildford grass (Romulea rosea) leaf and corms were a major component of the diet in the two habitats where this species was common. Further, as a result of the summer die-off of pasture species, there was a shift in where rabbits sourced food items during winter and summer. Pasture species were eaten during winter, but rabbits fed mainly on those dicotyledons found only in the surrounding scrub during summer. This suggests that rabbits may impact negatively upon such remnant vegetation at this time. Rabbits in all three habitats consumed several plant species with high water content (>54%) during summer, presumably to help maintain their water balance. Rabbits also consumed the seeds and foliage of several weed/nuisance species in each habitat, but any role of rabbits in weed dispersal was not determined.

2003 ◽  
Vol 25 (2) ◽  
pp. 135 ◽  
Author(s):  
SA Ryan ◽  
KE Moseby ◽  
DC Paton

Dietary preferences of the greater stick-nest rat (Leporillus conditor) and the European rabbit (Oryctolagus cuniculus) were compared using cafeteria trials and direct observations. Despite overlap, these species exhibited differences in dietary preference. L. conditor showed a strong preference for chenopod shrub species and other plant species with a high water content including Gunniopsis quadrifida and Calandrinia remota. L. conditor also preferred female bladder saltbush (Atriplex vesicaria) foliage to male. O. cuniculus ate a greater selection of plant species in most trials with their most preferred species including mulga (Acacia aneura), Salsola kali and Calandrinia remota. Both O. cuniculus and L. conditor preferred seedlings of perennial species to adult cuttings. L. conditor has recently been re-introduced to a 14 km� O. cuniculus, cat (Felis catus) and red fox (Vulpes vulpes) proof exclosure in the arid zone of South Australia. The re-introduction of this herbivore and the removal of exotic herbivores may change the vegetation structure and composition within the exclosure by restricting growth of some succulent chenopod species but allowing the regeneration of tall shrub species such as Acacia aneura which are usually limited by O. cuniculus grazing.


2020 ◽  
Vol 19 (1) ◽  
pp. 21-39
Author(s):  
Marta Rokosa ◽  
Małgorzata Mikiciuk

The genus Fragaria belongs to the Rosaceae family. The most popular representatives of this species are the strawberry (Fragaria × ananassa Duch.) and wild strawberry (Fragaria vesca L.), whose taste and health benefits are appreciated by a huge number of consumers. The cultivation of Fragaria plants is widespread around the world, with particular emphasis on the temperate climate zone. Increasingly occurring weather anomalies, including drought phenomena, cause immense losses in crop cultivation. The Fragaria plant species are very sensitive to drought, due to the shallow root system, large leaf area and the high water content of the fruit. There have been many studies on the influence of water deficit on the morphological, biochemical and physiological features of strawberries and wild strawberries. There is a lack of research summarizing the current state of knowledge regarding of specific species response to water stress. The aim of this study was to combine and compare data from many research carried out and indicate the direction of future research aimed at improving the resistance of Fragaria plants species to stress related to drought. These plants show patterns of response to stress caused by drought, such as: osmotic adjustment, reduction of transpiration and photosynthesis, and increased efficiency of water use. Drought also causes significant changes in the composition and palatability of the fruit of the Fragaria plant species.


Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 115
Author(s):  
Mengmeng Li ◽  
Jian Kang

Plant leaves respond to environmental sounds by vibration. This study aimed to examine such responses by evaluating the influences of physical properties on vibrational amplitude, velocity and frequency before and during sound stimulation. Nine plant species with a wide range of leaf sizes, qualities and thicknesses and petiole lengths, widths and thicknesses were selected. In the absence of external sound, the leaf amplitude was ~1 μm, the vibrational velocity was ~0.05 mm s-1 and the vibrational frequency was ~0–15 Hz. After sound stimulation, however, the amplitude increased by 1–5.4×, the velocity was 1.75–14.1× higher and produced another spectral peak at ~80–95 Hz. Nevertheless, the amplitude and velocity varied by up to 1–10× among species mainly because of differences in leaf texture. However, these factors did not markedly change in succulent leaves because their thick epidermal cuticles and high water content buffered vibrations. In contrast, leathery leaves and papery and membranous leaves were highly responsive to sound stimuli. Leaf size, mass and thickness and petiole length, width and thickness also influenced leaf vibration. There is a positive correlation between noise reduction and leaf velocity. Noise reduction effect increases with the increase in leaf velocity until about 0.6 mm s−1 and then decreases. The relationship between leaf physical properties and leaf vibration may be used to study sound response and noise reduction in different plant species.


Author(s):  
A. Bykov ◽  
D. Palatov ◽  
I. Studenov ◽  
D. Chupov

The article provides information about the features of spring feeding of sterlet in the spawning grounds of the middle course of the Northern Dvina river in may 2019. The main and secondary groups of forage objects in the diet of this species of sturgeon are characterized. The article considers the variability of the sterlet food composition with an increase in the size of fish from 30 to 60 cm. In the process of fish growth in the diet of the Severodvinsk sterlet, the main components in terms of occurrence and mass in all size groups are the larvae of Brooks and chironomids. A minor occurrence was the larvae of midges, biting midges, stoneflies, mayflies and small clams. To random and seasonal food are the larvae of water bugs, butterflies, flies, beetles and eggs of other fish. The feeding intensity of the smaller sterlet (30–40 cm) was significantly higher than that of the fish in the size groups 40–50 and 50–60 cm. Fundamental changes in the diet of the Severodvinsk sterlet for the main food objects for more than sixty years of observations have not been established. During periods of high water content of the Northern Dvina due to seasonal changes in the structure of benthic communities, the value of Brooks in the diet of sterlet increases and the proportion of chironomids decreases.


2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.


2019 ◽  
Vol 67 (7) ◽  
pp. 4803-4810 ◽  
Author(s):  
Xiong Wang ◽  
Tao Qin ◽  
Yexian Qin ◽  
Ahmed H. Abdelrahman ◽  
Russell S. Witte ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shun-ichiro Karato ◽  
Bijaya Karki ◽  
Jeffrey Park

AbstractOceans on Earth are present as a result of dynamic equilibrium between degassing and regassing through the interaction with Earth’s interior. We review mineral physics, geophysical, and geochemical studies related to the global water circulation and conclude that the water content has a peak in the mantle transition zone (MTZ) with a value of 0.1–1 wt% (with large regional variations). When water-rich MTZ materials are transported out of the MTZ, partial melting occurs. Vertical direction of melt migration is determined by the density contrast between the melts and coexisting minerals. Because a density change associated with a phase transformation occurs sharply for a solid but more gradually for a melt, melts formed above the phase transformation depth are generally heavier than solids, whereas melts formed below the transformation depth are lighter than solids. Consequently, hydrous melts formed either above or below the MTZ return to the MTZ, maintaining its high water content. However, the MTZ water content cannot increase without limit. The melt-solid density contrast above the 410 km depends on the temperature. In cooler regions, melting will occur only in the presence of very water-rich materials. Melts produced in these regions have high water content and hence can be buoyant above the 410 km, removing water from the MTZ. Consequently, cooler regions of melting act as a water valve to maintain the water content of the MTZ near its threshold level (~ 0.1–1.0 wt%). Mass-balance considerations explain the observed near-constant sea-level despite large fluctuations over Earth history. Observations suggesting deep-mantle melting are reviewed including the presence of low-velocity anomalies just above and below the MTZ and geochemical evidence for hydrous melts formed in the MTZ. However, the interpretation of long-term sea-level change and the role of deep mantle melting in the global water circulation are non-unique and alternative models are reviewed. Possible future directions of studies on the global water circulation are proposed including geodynamic modeling, mineral physics and observational studies, and studies integrating results from different disciplines.


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