Cattle grazing in a hummock grassland regenerating after fire: the short-term effects of cattle exclusion on vegetation in south-western Queensland

2004 ◽  
Vol 26 (1) ◽  
pp. 34 ◽  
Author(s):  
Mike Letnic
Keyword(s):  
Species Richness ◽  
Additional Data ◽  
Cattle Grazing ◽  
Wet Season ◽  
Short Term ◽  
Soil Crusts ◽  
Species Composition Of Vegetation ◽  
Vegetation Surveys ◽  
Vertical Density ◽  
Simpson Desert

In the Simpson Desert of western Queensland fire is being used increasingly by pastoralists to manipulate hard spinifex (Triodia basedowii) pastures. In this study I investigated the short-term (20 month) effects of cattle grazing on hummock grasslands regenerating after fire in the Simpson Desert. Dung counts were used to determine if cattle grazed preferentially in areas regenerating after fire. Cattle exclosures and vegetation surveys were used to determine if grazing by cattle affected the structure and species composition of vegetation regenerating after fire. Cattle grazed preferentially in areas regenerating after fire. Cattle grazing reduced the cover, height, vertical density and species richness of regrowth vegetation. Grazing reduced the cover of Ptilotus polystachyus and reduced the proportion of Eragrostis eriopodia individuals bearing flowers and seed. Grazing visibly disrupted microbiotic soil crusts. It is recommended, as a precaution until additional data is available, that areas regenerating after fire be rested from grazing during the first post-fire wet season. Resting during this period will assist the establishment of vegetation cover and provide opportunities for grasses to set seed.

scholarly journals First reports of short-term temporal variations in crustacean species richness in north Patagonian coastal temporary pools

Nauplius ◽  
2021 ◽  
Vol 29 ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Francisco Encina-Montoya ◽  
Eriko Carreño ◽  
Francisco Correa-Araneda ◽  
Carlos Esse
Keyword(s):  
Species Richness ◽  
Temporal Variations ◽  
Temporary Pools ◽  
Short Term ◽  
Crustacean Species

Helminth communities in murid rodents from southern and northern localities in Lao PDR: the role of habitat and season

2013 ◽  
Vol 88 (3) ◽  
pp. 302-309 ◽  
Author(s):  
N. Pakdeenarong ◽  
P. Siribat ◽  
K. Chaisiri ◽  
B. Douangboupha ◽  
A. Ribas ◽  
...  
Keyword(s):  
Species Richness ◽  
Lao Pdr ◽  
Nematode Species ◽  
Helminth Species ◽  
Hymenolepis Diminuta ◽  
Wet Season ◽  
South East Asian Region ◽  
Helminth Communities ◽  
Murid Rodents

AbstractThe helminth communities of wild murid rodents were investigated in Luang Prabang and Champasak province, Lao PDR. Thirteen species of rodents (404 individuals) were infected by 19 species of parasites (2 trematode, 3 cestode, 14 nematode species). Four of the recorded helminth species (Echinostoma malayanum,Raillietinasp.,Hymenolepis diminutaandH. nana)are known to cause potential zoonotic helminthiases of medical importance in the South-East Asian region. Individual helminth infection was significantly higher in the wet season. Habitat significantly influenced individual helminth species richness and individual helminth abudance, with a decrease of individual helminth species richness and individual helminth abundance from forest habitat to agricultural and human settlement habitats. The reduction of helminth diversity and abundance is discussed in relation to the ongoing increase of human influence on habitats in Lao PDR.

Diet determination of cattle grazing in the Sanyati communal areas in Zimbabwe

2006 ◽  
Vol 34 ◽  
pp. 35-40
Author(s):  
Hanne H. Hansen ◽  
Jørgen Madsen
Keyword(s):  
Plant Species ◽  
Cattle Grazing ◽  
Dry Season ◽  
Particle Identification ◽  
Grass Species ◽  
Wet Season ◽  
Communal Area ◽  
Communal Areas

SummaryThe diet of cattle grazing in the Sanyati communal area, Zimbabwe was determined using plant particle identification from faeces from intact animals, and faeces and oesophageal extrusa from fistulated animals. A total of 130 plant genus, species and types were identified. The twenty most frequently occurring species in the samples comprised between 76 and 90% of the identifiable diet. The most frequent grass species were more than half of the identified diet in the dry season while they were half or less of the identified diet in the wet season. There were more plant species identified in the wet season than in the dry season. Significant differences were found when comparing the plant species identified in faeces to those in oesophageal extrusa from fistulated animals. This may be due to incomplete recovery of ingesta in the bags, or to the loss of identifiable particles in the faeces when compared to oesophageal extrusa because of digestibility. More research is needed to validate the use of oesophageal extrusa for diet botanical determination.

The short-term effects of an extensive and high-intensity fire on vertebrates in the tropical savannas of the central Kimberley, northern Australia

2008 ◽  
Vol 35 (1) ◽  
pp. 33 ◽  
Author(s):  
Sarah Legge ◽  
Stephen Murphy ◽  
Joanne Heathcote ◽  
Emma Flaxman ◽  
John Augusteyn ◽  
...  
Keyword(s):  
Species Richness ◽  
High Intensity ◽  
Fire Frequency ◽  
Northern Australia ◽  
Tropical Savannas ◽  
Short Term ◽  
Large Herbivores ◽  
Species Richness And Abundance ◽  
Species Specific ◽  
In Fire

We report the effects of an extensive (>7000 km2), high-intensity late-dry-season fire in the central Kimberley, Western Australia, on the species richness and abundance of mammals, reptiles and birds. Five weeks after the fire we surveyed 12 sites (six burnt, six unburnt); each pair of sites was closely matched for soil type and vegetation. The species richness and abundance of mammals and reptiles was greater at unburnt sites, especially for mammals (with a 4-fold difference in abundance between burnt and unburnt sites). There was an indication that reptiles immigrated into unburnt patches, but mammals did not. There were also species-specific responses to the fire: Rattus tunneyi and Pseudomys nanus were much more abundant in unburnt sites, whereas Pseudomys delicatulus was caught in equal numbers at burnt and unburnt sites. Diurnal reptiles were more abundant at unburnt sites, but nocturnal reptiles were equally common at burnt and unburnt sites. Avian species richness and overall abundance was similar between burnt and unburnt patches, although a few species showed preferences for one state or the other. The overall high trapping success for mammals (18% across all sites; 28% in unburnt patches) contrasts with the well documented mammal collapse in parts of northern Australia and seems paradoxical given that our study area has experienced the same increase in fire frequency and extent that is often blamed for species collapse. However, our study area has fewer pressures from other sources, including grazing by large herbivores, suggesting that the effects of these pressures, and their interaction with fire, may have been underestimated in previous studies.

Diet selection by cattle grazing Stylosanthes-grass pastures in the seasonally dry tropics: effect of year, season, stylo species and botanical composition

1996 ◽  
Vol 36 (7) ◽  
pp. 781 ◽  
Author(s):  
DB Coates
Keyword(s):  
Cattle Grazing ◽  
Diet Selection ◽  
Dry Season ◽  
Major Influence ◽  
Botanical Composition ◽  
Wet Season ◽  
Seasonally Dry ◽  
Dietary Preference ◽  
Dry Tropics ◽  
Opportunity For Selection

The dietary preference of cattle grazing Stylosanthes-based pastures in the seasonally dry tropics of North Queensland was studied using faecal carbon ratios (S13C) to determine grass-legume proportions. Estimates were made at monthly intervals for several years in 1 experiment to determine the effect of year, season and botanical composition on dietary stylo proportions. In another experiment, the effect of stylo cultivars (Verano and Seca) on dietary preference was monitored for 17 months. Where pastures provided ample opportunity for selection, cattle showed a strong preference for grass in the early wet season and in the late dry season. The proportion of stylo in the diet increased during the wet season and reached peak proportions (as high as 80%) in the late wet season or early dry season. Dietary stylo proportions decreased as pastures dried off and as the stylo shed leaf or became more stemmy. The length of the wet season and the amount and distribution of rainfall had a major influence on the seasonal pattern of diet selection. Stylo rarely fell below 20% in the diet. On an annual basis, stylo accounted for about 45% of the diet which was appreciably higher than the proportion of stylo in the pasture. Dietary stylo proportions were higher on Seca-based pasture than on Verano-based pasture. The avoidance of stylo in the early wet season was less pronounced with Seca compared with Verano. Later in the season Seca was the dominant dietary component for a much longer period than Verano. The effect of botanical composition on dietary grass-legume proportions varied between and within years. Correlations between grass-legume proportions in the pasture and in the diet were highest in the late dry season and early wet season when preference for grass was strongest. At the end of the wet season when cattle preferred stylo, dietary stylo was not related to pasture stylo content except in a drought year. Averaged over the full year, dietary stylo content was significantly correlated with pasture stylo content in all years and the correlation was highest in a drought year when there was a high level of utilisation and less opportunity for selection. A simple model relating dietary stylo to pasture stylo was developed and is discussed.

Creep feeding and prepartum supplementation effects on growth and fertility of Brahman-cross cattle in the dry tropics

1996 ◽  
Vol 36 (4) ◽  
pp. 389 ◽  
Author(s):  
G Fordyce ◽  
NJ Cooper ◽  
IE Kendall ◽  
BM O'Leary ◽  
Jde Faveri ◽  
...  
Keyword(s):  
Post Partum ◽  
Bos Indicus ◽  
Weather Conditions ◽  
Wet Season ◽  
Short Term ◽  
Research Committee ◽  
Creep Feeding ◽  
Dry Tropics ◽  
Creep Feed ◽  
Short Period

Post-partum anoestrus is a primary contributor to low branding rates in Bos indicus cattle herds in the dry tropics of northern Australia [Entwistle, K. W. (1983). Australian Meat Research Committee Review No. 431. To increase branding rates, it was hypothesised that creep feeding for a short period in mid-late lactation during the latter half of the growing season may trigger an earlier onset of post-partum oestrus cycling, just as short-term, high-level, prepartum supplementation can achieve. Two experiments were conducted using Fn Brahman-cross cows (1/2, 5/8 and 3/4 crosses with Beef Shorthorn) which calved from late October to late Januarv. Cows were mated from mid-late Januarv to mid-April. Calves in one treatment in both experiments had ad libitum access to creep feed (calf pellets: 16% crude protein, 10 MJ ME/kg) for 4042 days from late February to early April. In experiment 2, the effects on cow growth and fertility due to supplementation with either cottonseed meal (1.5 kg/day) or molasses with 7.4% (w/w) urea for 49 days late in the dry season before calving ('spike' feeding) were also evaluated. Control cattle were unsupplemented. Creep feed was only consumed at 0.1 and 0.4 kg/day in experiments 1 and 2, respectively. Short-term creep feeding had no consistent effects on cow liveweights, condition, or fertility, or on calf growth and temperaments under extensive grazing conditions during the tropical wet season. Spike feeding reduced weight loss by 0.2-0.4 kg/day (P<0.01). The effects on liveweights did not persist into the wet season. There were no effects on cow fertility in this year of extreme weather conditions, when 4 months of nutritional and climatic stress followed supplementation.

NORTHRIDGE, CALIFORNIA, EARTHQUAKE CRUDE OIL SPILL: EFFECTS ON THE BIRD COMMUNITY

1997 ◽  
Vol 1997 (1) ◽  
pp. 1032-1033
Author(s):  
Joan Duffield ◽  
Susan Dearn ◽  
Marion Fischel
Keyword(s):  
Species Richness ◽  
Crude Oil ◽  
Oil Spill ◽  
Bird Community ◽  
Habitat Availability ◽  
Short Term ◽  
Avian Abundance ◽  
Crude Oil Spill

ABSTRACT Four months after the release of San Joaquin blended crude oil into the Santa Clara River, California, avian surveys were conducted to determine if there were any detectable effects on the bird community. Although mean avian abundance and species richness varied considerably within and between oiled and non-oiled areas, these differences appeared to be a function of habitat availability and heterogeneity rather than oil-related impacts. Overall, although there were some short-term impacts immediately following the spill, there were no determinable effects on the avian resources surveyed four months later.

scholarly journals Predicting mutational routes to new adaptive phenotypes

2018 ◽  
Author(s):  
Peter A. Lind ◽  
Eric Libby ◽  
Jenny Herzog ◽  
Paul B. Rainey
Keyword(s):  
Mathematical Modelling ◽  
Adaptive Evolution ◽  
Experimental Evolution ◽  
Additional Data ◽  
Mutation Rates ◽  
Mechanistic Models ◽  
Short Term ◽  
Regulatory Pathways ◽  
Fitness Effects ◽  
Mutational Hotspots

AbstractPredicting evolutionary change poses numerous challenges. Here we take advantage of the model bacterium Pseudomonas fluorescens in which the genotype-to-phenotype map determining evolution of the adaptive “wrinkly spreader” (WS) type is known. We present mathematical descriptions of three necessary regulatory pathways and use these to predict both the rate at which each mutational route is used and the expected mutational targets. To test predictions, mutation rates and targets were determined for each pathway. Unanticipated mutational hotspots caused experimental observations to depart from predictions but additional data led to refined models. A mismatch was observed between the spectra of WS-causing mutations obtained with and without selection due to low fitness of previously undetected WS-causing mutations. Our findings contribute toward the development of mechanistic models for forecasting evolution, highlight current limitations, and draw attention to challenges in predicting locus-specific mutational biases and fitness effects.Impact statementA combination of genetics, experimental evolution and mathematical modelling defines information necessary to predict the outcome of short-term adaptive evolution.

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