Impact of grazing on fine fuels and potential wildfire behaviour in a non-native tropical grassland

2015 ◽  
Vol 21 (2) ◽  
pp. 126 ◽  
Author(s):  
Edward W. Evans ◽  
Lisa M. Ellsworth ◽  
Creighton M. Litton
Keyword(s):  
Cattle Grazing ◽  
Model Potential ◽  
Fire Frequency ◽  
Flame Length ◽  
Conclusive Evidence ◽  
Livestock Grazing ◽  
Ecological Processes ◽  
Native Grass ◽  
Fuel Loads ◽  
The Tropics

Non-native grass invasion has increased fuel loads and fire frequency in areas throughout the tropics, resulting in a non-native grass–wildfire cycle with negative impacts on native biodiversity and ecological processes. Megathyrsus maximus (guinea grass) invades dry and mesic ecosystems throughout the tropics, increasing fuel loads and wildfire intensity. Eradication of M. maximus is difficult, making effective wildfire management critical to the protection of adjacent developed areas and remnant native ecosystems. The use of domestic livestock grazing in non-native grass ecosystems may be effective at decreasing fine fuel loads and potential wildfire behaviour. Our objectives were to: (1) quantify live and dead fine fuel loads and moistures in a M. maximus–dominated ecosystem before and after cattle grazing, and (2) use these data to model potential wildfire behaviour in grazed and ungrazed M. maximus grasslands with the BehavePlus fire modelling system. Fine fuel loads and moistures, climate variables, and predicted wildfire behaviour were quantified at the same site (n = 1) over two 5-month periods (March–July 2009, ungrazed; March–July 2010, grazed) in the Wai‘anae Kai Forest Reserve on the Island of O‘ahu, Hawai‘i. Strong to conclusive evidence existed that cattle grazing in this system decreased dead and total fuel loads, but did not alter live fuel loads, or live and dead fuel moistures. Modelled wildfire behaviour under both low and average fuel moisture scenarios revealed that grazing decreased the potential rate of spread by 44–52% and flame length by 36–41%. These results demonstrate that cattle grazing may be an effective approach for reducing fuel loads and potential wildfire behaviour in non-native-dominated grasslands on tropical islands.

scholarly journals Exploring the Future of Fuel Loads in Tasmania, Australia: Shifts in Vegetation in Response to Changing Fire Weather, Productivity, and Fire Frequency

Forests ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 210 ◽  
Author(s):  
Rebecca Harris ◽  
Tomas Remenyi ◽  
Paul Fox-Hughes ◽  
Peter Love ◽  
Nathaniel Bindoff
Keyword(s):  
Fire Frequency ◽  
Fire Weather ◽  
Fuel Loads ◽  
The Future

scholarly journals Livestock grazing is associated with seasonal reduction in pollinator biodiversity and functional dispersion but cheatgrass invasion is not: variation in bee assemblages in a multi-use shortgrass prairie

2020 ◽  
Author(s):  
Khum Bahadur Thapa-Magar ◽  
Thomas Seth Davis ◽  
Boris C. Kondratieff
Keyword(s):  
Growing Season ◽  
Cattle Grazing ◽  
Soil Disturbance ◽  
Livestock Grazing ◽  
Native Plant ◽  
Native Plant Species ◽  
Shortgrass Prairie ◽  
Functional Dispersion ◽  
Bee Communities ◽  
Bee Abundance

AbstractLivestock grazing and non-native plant species affect rangeland habitats globally. These factors may have important effects on ecosystem services including pollination, yet, interactions between pollinators, grazing, and invasive plants are poorly understood. To address this, we tested the hypothesis that cattle grazing and site colonization by cheatgrass (Bromus tectorum) impact bee foraging and nesting habitats, and the biodiversity of wild bee communities, in a shortgrass prairie system. Bee nesting habitats (litter and wood cover) were marginally improved in non-grazed sites, though foraging habitat (floral cover and richness) did not differ among grazed, non-grazed, or cheatgrass colonized sites. However, floral cover was a good predictor of bee abundance and functional dispersion. Mean bee abundance, richness, diversity and functional diversity were significantly lower in cattle-grazed habitats than in cheatgrass-colonized or non-grazed habitats. Differences in bee diversity among habitats were pronounced early in the growing season (May) but by late-season (August) these differences eroded. Fourth-corner analysis revealed that sites with high floral cover tended to support large, social, polylectic bees; sites with high grass cover tended to support oligolectic solitary bees. Both cattle-grazed and cheatgrass-colonized sites were associated with lower abundances of above-ground nesting bees but higher abundance of below-ground nesters. We conclude that cheatgrass-invaded sites are not associated with reduced bee biodiversity or abundance, but cattle grazing was negatively associated with bee abundances and altered species composition. Although floral cover is an important predictor of bee assemblages, this was not impacted by grazing and our suggests that cattle likely impact bee communities through effects other than those mediated by forbs, including soil disturbance or nest destruction. Efforts aimed at pollinator conservation in prairie habitats should focus on managing cattle impacts early in the growing season to benefit sensitive bee species.

scholarly journals Effects of livestock grazing on flocks of seed-eating birds in the central Monte desert, Argentina

2019 ◽  
Vol 97 (7) ◽  
pp. 606-611
Author(s):  
A. Zarco ◽  
V.R. Cueto ◽  
M.C. Sagario ◽  
L. Marone
Keyword(s):  
Structural Characteristics ◽  
Resource Depletion ◽  
Cattle Grazing ◽  
Livestock Grazing ◽  
Foraging Efficiency ◽  
Monte Desert ◽  
Management Actions ◽  
Animal Populations ◽  
Nuclear Species ◽  
Seed Eating

Animal populations often decline due to habitat disturbance, but the initial response of organisms to human-induced environmental change is usually behavioral. Intra- and inter-specific interactions can restrict or facilitate access to resources, resulting in changes to individual fitness, and resource depletion may affect the frequency and strength of interactions. In birds, it is often assumed that feeding in groups increases foraging efficiency. We assessed how the reduction of seed resources provoked by cattle grazing affected different properties of seed-eating bird flocks in woodlands having the same structural characteristics but differing in seed abundance. Under lower availability of grass seeds (i.e., under grazing), flocks were smaller and less rich and birds showed a lower flocking propensity. This pattern could be explained by three non-exclusive hypotheses. Food reduction caused by grazing (i) decreases the number of seed-eating birds and concomitantly generates smaller flocks; (ii) reduces the density of nuclear species, decreasing the group cohesion in large flocks; (iii) makes large flocks less attractive by increasing individual competence for food. Our results provide evidence that cattle grazing affect the interactions of seed-eating birds and suggest the importance of understanding flocking behavior to bring about management actions.

Effect of superphosphate application on macro-nutrient and micro-nutrient concentrations in grazed stylo-native grass pasture in tropical Australia

1992 ◽  
Vol 43 (8) ◽  
pp. 1725
Author(s):  
RE Hendricksen ◽  
MA Gilbert ◽  
LD Punter
Keyword(s):  
Species Interactions ◽  
Nutrient Concentration ◽  
Cattle Grazing ◽  
Plant Part ◽  
Low Fertility ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Single Superphosphate ◽  
Native Grass ◽  
Themeda Triandra

Soils of northern Australia are generally old, strongly weathered, and of low fertility status. Some knowledge of the status of nitrogen, phosphorus and sulfur and its effects on pasture productivity is available from small plot trials, but few detailed studies of macro-nutrient and micro-nutrient levels in grazed pastures have been reported. Such a study from a site near Mareeba in north Queensland has recently been completed. The major components of the pasture were kangaroo grass ( Themeda triandra), giant speargrass (Heteropogon triticeus) and the legumes, Stylosanthes scabra cv. Seca and S. hamata cv. Verano, which were oversown into the native grass pasture 6 years previously. Generally, the effects of superphosphate on nutrient concentration were minor compared with the effects of season, plant part and species. Superphosphate application increased concentrations of P and S, but decreased concentrations of Zn and Mo and the N/S ratio in both sets of legume and grass. There was no effect on the concentrations of N, K, Na, Ca, Cu and Co. Fertilizer effects did not often interact significantly (P < 0.05) with season, species and plant part (green leaf and stem). Seasonal changes in nutrient concentration were not consistent for all nutrients. As the growing season progressed from December to June, concentrations of the mobile nutrients, N, P, K, Na, Cl, S, Se and I decreased, the immobile nutrients Ca and Mo increased, but Mg, Cu and Co and the N/S ratio remained relatively constant. Both Zn and Mn concentrations remained constant with season in the legumes, but increased in the grasses. Season * species interactions were often significant for the grasses possibly due to the differing maturity patterns of kangaroo grass and giant spear grass. Cattle grazing the native pasture during the wet season are likely to be deficient in N, P, Na, S and Cu based on the nutrient concentrations in plucked pasture samples and published dietary requirements. However, cattle grazing productive stylo - native grass pasture which has received adequate single superphosphate are likely to suffer only from Na deficiency. At suboptimal levels of superphosphate, a deficiency of P in the diet is also indicated.

Spatial and temporal variability of guinea grass (Megathyrsus maximus) fuel loads and moisture on Oahu, Hawaii

2013 ◽  
Vol 22 (8) ◽  
pp. 1083 ◽  
Author(s):  
Lisa M. Ellsworth ◽  
Creighton M. Litton ◽  
Andrew D. Taylor ◽  
J. Boone Kauffman
Keyword(s):  
Temporal Variability ◽  
Spatial And Temporal Variability ◽  
Weather Variables ◽  
Specific Data ◽  
Fuel Loads ◽  
Temperature And Precipitation ◽  
Guinea Grass ◽  
Fine Fuels ◽  
The Tropics ◽  
Native Invasive

Frequent wildfires in tropical landscapes dominated by non-native invasive grasses threaten surrounding ecosystems and developed areas. To better manage fire, accurate estimates of the spatial and temporal variability in fuels are urgently needed. We quantified the spatial variability in live and dead fine fuel loads and moistures at four guinea grass (Megathyrsus maximus) dominated sites. To assess temporal variability, we sampled these four sites each summer for 3 years (2008–2010) and also sampled fuel loads, moistures and weather variables biweekly at three sites for 1 year. Live and dead fine fuel loads ranged spatially from 0.85 to 8.66 and 1.50 to 25.74Mgha–1 respectively, and did not vary by site or year. Biweekly live and dead fuel moistures varied by 250 and 54% respectively, and were closely correlated (P<0.05) with soil moisture, relative humidity, air temperature and precipitation. Overall, fine fuels and moistures exhibited tremendous variability, highlighting the importance of real-time, site-specific data for fire prevention and management. However, tight correlations with commonly quantified weather variables demonstrates the capacity to accurately predict fuel variables across large landscapes to better inform management and research on fire potential in guinea grass ecosystems in Hawaii and throughout the tropics.

The influence of superphosphate on the legume content of the diet selected by cattle grazing Stylosanthes-native grass pastures

1981 ◽  
Vol 96 (1) ◽  
pp. 247-249 ◽  
Author(s):  
R. W. McLean ◽  
W. H. Winter ◽  
J. J. Mott ◽  
D. A. Little
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Direct Evidence ◽  
Cattle Grazing ◽  
Beef Production ◽  
Native Grass

The addition of superphosphate increases the legume content of grass-legume pastures and the growth rate of beef cattle (Shaw, 1978). It has generally been assumed that the increase in beef production following the application of superphosphate is related directly to greater amounts of legume in the pasture consumed (Norman, 1970; Shaw, 1978) but there is no direct evidence on this subject. This paper reports a study of the influence of small quantities of superphosphate on preference for legume by cattle grazing Stylosanthes-native grass pastures.

The Effect of Antibiotics and lonophores on the Gain of Stocker Cattle Grazing Native Grass Pasture1

1990 ◽  
Vol 6 (3) ◽  
pp. 19-23 ◽  
Author(s):  
F.K. Brazle ◽  
G. Kuhl ◽  
D.L. Harmon ◽  
W.M. larson ◽  
K.S. Lusby
Keyword(s):  
Cattle Grazing ◽  
Native Grass ◽  
Stocker Cattle

scholarly journals Fire-induced loss of the world’s most biodiverse forests in Latin America

2021 ◽  
Vol 7 (33) ◽  
pp. eabd3357
Author(s):  
Dolors Armenteras ◽  
Liliana M. Dávalos ◽  
Joan S. Barreto ◽  
Alejandro Miranda ◽  
Angela Hernández-Moreno ◽  
...  
Keyword(s):  
Climate Change ◽  
Latin America ◽  
Latin American ◽  
Dominant Role ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Forest Loss ◽  
Evergreen Forests ◽  
Relative Extent ◽  
The Tropics

Fire plays a dominant role in deforestation, particularly in the tropics, but the relative extent of transformations and influence of fire frequency on eventual forest loss remain unclear. Here, we analyze the frequency of fire and its influence on postfire forest trajectories between 2001 and 2018. We account for ~1.1% of Latin American forests burnt in 2002–2003 (8,465,850 ha). Although 40.1% of forests (3,393,250 ha) burned only once, by 2018, ~48% of the evergreen forests converted to other, primarily grass-dominated uses. While greater fire frequency yielded more transformation, our results reveal the staggering impact of even a single fire. Increasing fire frequency imposes greater risks of irreversible forest loss, transforming forests into ecosystems increasingly vulnerable to degradation. Reversing this trend is indispensable to both mitigate and adapt to climate change globally. As climate change transforms fire regimes across the region, key actions are needed to conserve Latin American forests.

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