Feeding Preferences of the Italian Roe Deer (Capreolus capreolus italicus Festa, 1925) in a Coastal Mediterranean Environment

The present study was aimed to deepen the knowledge on diet and on feeding preferences of the Italian roe deer. The research was carried on in the Castelporziano Presidential Estate, a protected area of Latium coast. Quadrat method was used to assess plant frequency, whereas diet composition was determined by fecal micro-histological analysis. A total of 143 plant species were identified in the site and 109 of them were found in the feces of the Capreolus capreolus italicus. All over the year, most of the taxa were ingested in low percentages (≤5%) and the most utilized plant species were Quercus suber, Prunus spinosa, Rubia peregrina, and Crateaegus monogyna. Fagaceae and Rosaceae plant families represented the bulk of the diet and were positively selected. In addition, a positive selection on Fabaceae and Oleaceae families was found in wet season but not in dry one. In both periods the Italian roe deer showed a positive selection for deciduous woody plants and evergreen woody plants, instead avoided wild forbs and wild graminoids. Our results confirmed that this subspecies behaved as a generalist highly selective feeder.

Grasswise: monocultures or binary grass mixtures for African rangelands users?

<p>Reseeding, using drought tolerant indigenous perennial grasses is a viable option for combating rangeland degradation, provision of livestock feed and improving livelihoods of pastoral communities. However, debates on whether monocultures or binary grass mixtures establishments are best suited for African rangelands managers, are still ongoing. Our opinion and contribution to this debate is informed by results obtained from a combination of an ecological field based and socioeconomic study in a typical semi-arid rangeland in Kenya. Perennial forage grasses indigenous to African rangelands Cenchrus ciliaris (African foxtail grass), Enteropogon macrostachyus (Bush rye grass) and Eragrostis superba (Maasai love grass) were established as monocultures and binary grass mixtures. Binary grass mixtures demonstrated significantly higher rehabilitation indices for plant frequency, basal cover and plant densities and soil hydrological properties (infiltration capacity, runoff and sediment production). However, pastoral communities showed preference to monoculture than binary mixtures. This was attributed to their role in livestock production. In conclusion, considering the ecological and socio-economic value of African rangelands to pastoral communities, the choice of either monoculture or binary grass mixture establishment will primarily be informed by the principle objective(s) of the rangeland manager.    </p><p> </p>

Summer production and survival of perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) genotypes in northern Victoria under differing irrigation management

Perennial ryegrass (Lolium perenne L.) is the predominant perennial forage species used in temperate irrigated dairy-production systems in Australia. However, when temperatures are high, even with optimal irrigation strategies and nutrient inputs, dry matter (DM) production can be compromised. This research investigated the effects of perennial ryegrass and tall fescue genotypes and summer irrigation on (DM) production and survival. Ten perennial ryegrass cultivars, three hybrid ryegrasses and two cultivars of tall fescue (Festuca arundinacea (Schreb) Darbysh.) were sown in northern Victoria, Australia, in May 2014, and were managed under full irrigation or restricted irrigation (no irrigation between late December and mid-March) over a 3-year period. Measurements included net pasture accumulation (DM production), sward density (plant frequency) and water-soluble carbohydrate concentration. Apart from the expected differences in DM yield over the summer period between full irrigation and restricted irrigation, there were few differences in DM production among perennial ryegrass or tall fescue cultivars. Plant frequency declined significantly under restricted irrigation in Years 2 and 3 compared with full irrigation but there were no differences among perennial ryegrass cultivars. In Year 2, plant frequency was higher in the tall fescue cultivars than the ryegrass cultivars. The recovery pattern in DM production following recommencement of irrigation in mid-March (autumn) varied across years. In Year 1, plants recovered rapidly once irrigation recommenced in autumn. However, in Years 2 and 3, autumn and winter pasture accumulation under restricted irrigation was 30–35% less than under full irrigation. These differences were possibly related to decreases in plant frequency, as well as to differences in the amounts of residual pasture mass (or carbohydrate reserves) present when growth ceased. Analyses of the water-soluble carbohydrate concentrations in the pseudostem during summer and autumn in Year 3 showed differences in total water-soluble carbohydrate and in fructan and sucrose concentrations between irrigation treatments but no consistent differences among genotypes.

Grazing management of dairy pastures based on tall fescue in southern Australia

Tall fescue (Festuca arundinacea (Schreb) Darbysh.) has the potential to become a useful component of irrigated dairy pastures in northern Victoria owing to its high dry matter (DM) production compared with perennial ryegrass. However, tall fescue is not widely grown because its grazing management is perceived as difficult. In October 2010, a tall fescue–white clover pasture was established and irrigated. In September 2011, six grazing-management treatments were imposed over 3 years, involving grazing: at 1-leaf stage; at 2-leaf stage (1.5-leaf stage during spring); at 3-leaf stage (2.5-leaf stage during spring); at intervals based upon days between grazings ranging from 15 days in October–December to 60 days in winter; at intervals as above except for 21 days in October–December; and at intervals approximating that of a well-managed perennial-ryegrass-based pasture . Measurements included pre- and post-grazing pasture mass, nutritive characteristics, botanical composition and plant frequency. Pasture consumption from the treatment grazed at the 3-leaf stage was >3.5 t DM ha–1 year–1 (30%) greater than from the three most frequently grazed treatments. However, crude protein content was 1–3% DM units lower when grazed at the 3-leaf stage compared with the two most frequently grazed treatments. There was no effect on estimated metabolisable energy or neutral detergent fibre contents of the pasture on offer. Differences in pasture composition between the pastures grazed at the 3-leaf stage and those most frequently grazed emerged over time and were most conspicuous in the third year, with a greater plant frequency (79% v. 66%) and tall fescue content (61% v. 40% DM) and lower weed content (14% v. 28% DM). From the study, a grazing regime for tall fescue based on the 3-leaf stage appears promising because it produced the most DM over the experiment. A disadvantage of this regime was the need for an extra mowing each year. The practicality of this approach to grazing tall fescue needs to be tested at the whole-farm level.

Quantifying the relationship between pollinator behavior and plant reproductive isolation

ABSTRACTPollinator behavior is an important contributor to reproductive isolation in plants. Despite hundreds of years of empirical research, we lack a quantitative framework for evaluating how variation in pollinator behavior causes variation in reproductive isolation in plants. Here I present a model describing how two aspects of pollinator behavior – constancy and preference – lead to reproductive isolation in plants. This model is motivated by two empirical observations: most co-occurring plants vary in frequency over space and time and most plants have multiple pollinators that differ in behavior. These two observations suggest a need to understand how plant frequency and pollinator frequency influence reproductive isolation between co-occurring plants. My model predicts how the proportion of heterospecific matings varies over plant frequencies given pollinator preference and constancy. I find that the shape of this relationship is dependent on the strength of pollinator behavior. Additionally, my model incorporates multiple pollinators with different behaviors to predict the proportion of heterospecific matings across pollinator frequencies. I find that when two pollinators display different strength constancy the total proportion of heterospecific matings is simply the average proportion of heterospecific matings predicted for each pollinator. When pollinators vary in their preference the pollinator with the stronger preference disproportionally contributes to the predicted proportion of total heterospecific matings. I apply this model to examples of pollinator-mediated reproductive isolation in Phlox and in Mimulus to predict relationships between plant and pollinator frequency and reproductive isolation in natural systems.

Assessing grazing intensity plant frequency in Kordofan Region

This study was conducted in Um "Nabag" (15km north of "Bara"), "Dilling" (160km south of "Elobeid") and "Eldemiokya" (30km east of "Elobeid"). The main objective of this study is to assess the effect of grazing on growth performance of natural rangelands in Kordofan region. The specific objectives: To assess the effect of grazing level on vegetation frequency. The results showed different levels of grazing intensity at different sites as indicated by plants frequency and biomass. Intensive grazing levels were found at Bara in the north, early and late in the rainy season but in Dilling it was not found in the late in the rainy season for both seasons (2008 and 2009) which indicated longer stay of herders in "Bara" area as a rainy season residences. Frequency of the species between non- grazed and grazed areas showed a decrease for the two seasons especially for preferred species at the different sites as in the case of Eragrostis termula and Cenchrus biflorus in (2008 ),Similar results were observed in (2009) with Fimbirsty dichotomo and Cenchrus biflorus. The study recommended that grazing level can be used as practical mean to assess utilization level as expressed by growth performance indicators including frequency. Level (II) is expected to result in negative impact on rangeland plants growth performance. DOI: http://dx.doi.org/10.3126/ije.v4i2.12622 International Journal of Environment Vol.4(2) 2015: 27-37

Periodic disturbance rejection for fractional-order dynamical systems

This paper proposes a simple fractional-order derivative controller, based on an adaptive orthogonal signals generator, which permits both to reconstruct an unknown multi-sinusoidal disturbance and cancel its effect on the system output. An interesting feature is that the disturbance is removed by the generated internal signals with no additional dynamics in the cancellation algorithm. An opportune choice of the fractional-order controller guarantees the closed-loop stability of the system if the location of the plant frequency response at the estimated frequencies belongs to a halfplane passing through the origin of the complex plane, i.e. no information about the order of the system to be controlled, the relative degree, the nature of its poles and zeros, is required. The case of multi-sinusoidal disturbance is also analyzed. Simulations are presented that highlight the performances of the proposed method.

Ecological differentiation of Lemna minor L. and Spirodela polyrrhiza (L.) Schleiden populations

The subject of thep resent study are 19 natural, ecological populations of <i>Lemna minor</i> and <i>Spirodela polyrrhiza</i> coming from sixteen habitats in Lower Silesia. The study showed the essential differences between ecological populations of both species, conditioned on chemistry (pH, level N, P, K, Ca, Mg and Fe) and the natural water radioactivity. It was shown experimentally that these populations, in nature, establish a set of ecotypes or ecophene variability. Ecotypic differentiation of populations of <i>Lemna minor</i> and <i>Spirodela polyrrhiza</i> is based upon individual features and population characteristics such as: shape and size of plants, plant frequency of two, three, and four fronds, the ratio of right- to left-handed plants, and the dynamics of growth and biomass production.