The importance of nutrient hot-spots in the conservation and management of large wild mammalian herbivores in semi-arid savannas

2006 ◽  
Vol 130 (3) ◽  
pp. 426-437 ◽  
Author(s):  
C.C. Grant ◽  
M.C. Scholes
Keyword(s):  
Hot Spots ◽  
Mammalian Herbivores ◽  
Nutrient Hot Spots ◽  
Semi Arid ◽  
Conservation And Management

scholarly journals Interactions between large herbivores and litter removal by termites across a rainfall gradient in a South African savanna

2011 ◽  
Vol 27 (4) ◽  
pp. 375-382 ◽  
Author(s):  
Robert Buitenwerf ◽  
Nicola Stevens ◽  
Cleo M. Gosling ◽  
T. Michael Anderson ◽  
Han Olff
Keyword(s):  
Plant Biomass ◽  
Spatial Scales ◽  
Landscape Scale ◽  
Local Scale ◽  
Arid Ecosystems ◽  
Annual Rainfall ◽  
Large Herbivores ◽  
Mammalian Herbivores ◽  
Litter Removal ◽  
Semi Arid

Abstract:Litter-feeding termites influence key aspects of the structure and functioning of semi-arid ecosystems around the world by altering nutrient and material fluxes, affecting primary production, foodweb dynamics and modifying vegetation composition. Understanding these complex effects depends on quantifying spatial heterogeneity in termite foraging activities, yet such information is scarce for semi-arid savannas. Here, the amount of litter that was removed from 800 litterbags in eight plots (100 litterbags per plot) was measured in Hluhluwe–iMfolozi Park (HiP) South Africa. These data were used to quantify variation in litter removal at two spatial scales: the local scale (within 450-m2 plots) and the landscape scale (among sites separated by 8–25 km). Subsequently, we attempted to understand the possible determinants of termites’ foraging patterns by testing various ecological correlates, such as plant biomass and bare ground at small scales and rainfall and fences that excluded large mammalian herbivores at larger scales. No strong predictors for heterogeneity in termite foraging intensity were found at the local scale. At the landscape scale termite consumption depended on an interaction between rainfall and the presence of large mammalian herbivores: litter removal by termites was greater in the presence of large herbivores at the drier sites but lower in the presence of large herbivores at the wetter sites. The effect of herbivores on termite foraging intensity may indicate a switch between termites and large herbivore facilitation and competition across a productivity gradient. In general, litter removal decreased with increasing mean annual rainfall, which is in contrast to current understanding of termite consumption across rainfall and productivity gradients. These results generate novel insights into termite ecology and interactions among consumers of vastly different body sizes across spatial scales.

scholarly journals Effect of soil saturation on denitrification in a grassland soil

2017 ◽  
Vol 14 (20) ◽  
pp. 4691-4710 ◽  
Author(s):  
Laura Maritza Cardenas ◽  
Roland Bol ◽  
Dominika Lewicka-Szczebak ◽  
Andrew Stuart Gregory ◽  
Graham Peter Matthews ◽  
...  
Keyword(s):  
Hot Spots ◽  
Pore Space ◽  
Isotopic Fractionation ◽  
Nutrient Distribution ◽  
Grassland Soil ◽  
Flux Variability ◽  
Major Controlling Factor ◽  
Soil Cracks ◽  
Nutrient Hot Spots ◽  
Lower Saturation

Abstract. Nitrous oxide (N2O) is of major importance as a greenhouse gas and precursor of ozone (O3) destruction in the stratosphere mostly produced in soils. The soil-emitted N2O is generally predominantly derived from denitrification and, to a smaller extent, nitrification, both processes controlled by environmental factors and their interactions, and are influenced by agricultural management. Soil water content expressed as water-filled pore space (WFPS) is a major controlling factor of emissions and its interaction with compaction, has not been studied at the micropore scale. A laboratory incubation was carried out at different saturation levels for a grassland soil and emissions of N2O and N2 were measured as well as the isotopocules of N2O. We found that flux variability was larger in the less saturated soils probably due to nutrient distribution heterogeneity created from soil cracks and consequently nutrient hot spots. The results agreed with denitrification as the main source of fluxes at the highest saturations, but nitrification could have occurred at the lower saturation, even though moisture was still high (71 % WFSP). The isotopocules data indicated isotopic similarities in the wettest treatments vs. the two drier ones. The results agreed with previous findings where it is clear there are two N pools with different dynamics: added N producing intense denitrification vs. soil N resulting in less isotopic fractionation.

scholarly journals Effect of soil saturation on denitrification in a grassland soil

2017 ◽  
Author(s):  
Laura Maritza Cardenas ◽  
Roland Bol ◽  
Dominika Lewicka-Szczebak ◽  
Andrew Stuart Gregory ◽  
Graham Peter Matthews ◽  
...  
Keyword(s):  
Hot Spots ◽  
Pore Space ◽  
Isotopic Fractionation ◽  
Saturated Soils ◽  
Nutrient Distribution ◽  
Grassland Soil ◽  
Major Controlling Factor ◽  
Soil Cracks ◽  
Nutrient Hot Spots ◽  
Lower Saturation

Abstract. Nitrous oxide (N2O) is of major importance as a greenhouse gas and precursor of ozone (O3) destruction in the stratosphere mostly produced in soils. The soil emitted N2O is predominantly derived from denitrification and to a smaller extent, nitrification in soils, both processes controlled by environmental factors and their interactions, and are influenced by agricultural management. Soil water content expressed as water filled pore space (WFPS) is a major controlling factor of emissions and its interaction with compaction, has not been studied at the micropore scale. A laboratory incubation was carried out at different saturation levels for a grassland soil and emissions of N2O and N2 were measured as well as the isotopomers of N2O. We found that fluxes variability was larger in the less saturated soils probably due to nutrient distribution heterogeneity created from soil cracks and consequently nutrient hot spots. The results agreed with denitrification as the main source of fluxes at the highest saturations, but nitrification could have occurred at the lower saturation, even though moisture was still high (71 % WFSP). The isotopomer data showed isotopic similarities in the wettest treatments vs the two drier ones; and results agreed with previous findings where it is clear there are 2 N-pools with different dynamics: added N producing intense denitrification, vs soil N resulting in less isotopic fractionation.

scholarly journals Potential ecological distribution of alien mollusk Corbicula largillierti and its relationship with human disturbance in a semi-arid reservoir

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Evaldo de Lira Azevêdo ◽  
José Etham de Lucena Barbosa ◽  
Teofânia Heloisa Dutra Amorim Vidigal ◽  
João Carlos Marques ◽  
Marcos Callisto ◽  
...  
Keyword(s):  
Water Supply ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Human Disturbance ◽  
Aquatic Ecosystems ◽  
Freshwater Ecosystem ◽  
Ecological Distribution ◽  
Mollusk Species ◽  
Semi Arid ◽  
Conservation And Management

The introduction of exotic mollusk species has resulted in loss of biodiversity in semi-arid neotropical aquatic ecosystems. This study aims to relate the presence and density of Corbicula largillierti species to human disturbance, providing data for the conservation and management of aquatic ecosystems. Specimens were collected at Epitácio Pessoa reservoir in December 2011 and June 2012, presenting densities of 20.96 and 62.89 individuals per square meter, respectively. Anthropic disturbance metrics were calculated considering the presence, type and intensity of disturbance in littoral, riparian and flood zones. The occurrence of C. largillierti was mainly associated to the variables total phosphorus (261.05 ± 342.22 µg/L) and total nitrogen (440.79 ± 103.77 µg/L), near to tributaries. The occurrence of exotic mollusk species is evidence of the need for freshwater ecosystem conservation and management, particularly in reservoirs used for water supply.

scholarly journals Hunting Practices Among the Indigenous “Truká” in the Semiarid Region of Brazil

2020 ◽  
Vol 9 (31) ◽  
pp. 127-147
Author(s):  
Carlos Alberto Batista Santos
Keyword(s):  
Decision Making ◽  
Indigenous People ◽  
Natural Resource ◽  
Semiarid Region ◽  
Local Fauna ◽  
Wild Fauna ◽  
Local Perception ◽  
The Common ◽  
Semi Arid ◽  
Conservation And Management

This paper aims to provide information on hunting in the Semi-arid Northeast counting the hunting practices of the Truká Indigenous people. These pieces of information were obtained through interviews, using semi-structured questionnaires with fifty-five Indigenous hunters, distributed in four Truká villages located in the states of Bahia and Pernambuco. Thirty-nine poultries, thirteen mammals, and seven reptiles commonly captured the Truká have been cited. Out of the total number, forty-five (42.3%) were used for feeding. Species used as pets (n=20), in magic rituals (n=1), in traditional medicine (n=11), in local handicraft (n=23) and in control hunting (n=6) have also been quoted. Among those species, only one is listed as endangered, to say, Anodorhynchus leari, and one vulnerable, Leopardus tigrinus. Among the interviewees, the common hunting techniques are trap, hatch, pitfall, lasso, hunting net, rifle, slingshot, hook, besides handgrip and dog hunting. The awareness of local perception in the usage of wild fauna is fundamental for decision making in the elaboration of projects for the conservation and management of local fauna, aiming both the maintenance and the continuity of access to this natural resource.

Nutrient hot spots in some sierra Nevada forest soils

2010 ◽  
Vol 101 (1-3) ◽  
pp. 93-103 ◽  
Author(s):  
D. W. Johnson ◽  
D. W. Glass ◽  
J. D. Murphy ◽  
C. M. Stein ◽  
W. W. Miller
Keyword(s):  
Sierra Nevada ◽  
Forest Soils ◽  
Hot Spots ◽  
Nutrient Hot Spots

Nutrient Hot Spots in a Sierra Nevada Forest Soil

Soil Science ◽  
2013 ◽  
Vol 178 (11) ◽  
pp. 585-595 ◽  
Author(s):  
Casandra Woodward ◽  
Dale W. Johnson ◽  
Matthew W. Meadows ◽  
Watkins W. Miller ◽  
Meagan M. Hynes ◽  
...  
Keyword(s):  
Forest Soil ◽  
Sierra Nevada ◽  
Hot Spots ◽  
Nutrient Hot Spots

Is the removal of domestic stock sufficient to restore semi-arid conservation areas?

2000 ◽  
Vol 6 (3) ◽  
pp. 245 ◽  
Author(s):  
Manda J. Page ◽  
R. J. S. Beeton
Keyword(s):  
Natural Condition ◽  
National Park ◽  
Conservation Areas ◽  
Conservation Area ◽  
Mammalian Herbivores ◽  
Management Regime ◽  
South West ◽  
Domestic Livestock ◽  
Semi Arid ◽  
Domestic Stock

Increasingly, conservation areas are proclaimed in non-pristine environments that have biodiversity values and the issue of how to change the management regime to restore such landscapes arises. Before gazettal in 1992, Currawinya National Park (28�52'S, 144�30'E) in south-west Queensland's mulga lands was grazed by domestic stock for over 130 years. Following gazettal, the area was destocked and a monitoring programme initiated to determine the response by the vegetation. This paper describes the grass dynamics in three vegetation communities on Currawinya National Park with three different grazing regimes. Data are presented for an on-park site (native and feral herbivores present), an off-park site (domestic, native and feral herbivores were present), and an exclosure (no mammalian herbivores present). The results show that removal of domestic livestock alone is not sufficient to promote rapid recovery of grass populations, and suggest that conservation area managers must reduce native herbivore numbers as well if the desired outcome is a return to the supposed "natural" condition.

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