scholarly journals Carabid (Coleoptera) assemblages in the Scottish uplands: the influence of sheep grazing on ecological structure

2006 ◽  
Vol 17 (3) ◽  
Author(s):  
Lorna Cole ◽  
Meg Pollock ◽  
Duncan Robertson ◽  
John Holland ◽  
David McCracken

As a result of the European Community Common Agricultural Policy reform in 2005 it is predicted that livestock grazing in the Scottish uplands will become less intensive. At each of two upland research centres, two large (>40ha) plots were established to investigate the relationship between grazing intensity in the Scottish uplands and biodiversity. One plot was grazed intensively by sheep while the otherwas grazed extensively. Ground beetleswere sampled by pitfall trapping to determine the influence of grazing pressure on the ecologicalmake-up of ground beetle assemblages. Grazing intensity did not significantly influence carabid diversity. However, grazing intensity, altitude and moisture did influence the carabid ecological assemblage structure at both locations. Large flightless Carabus species were more abundant in extensively managed plots than intensively managed plots at both locations. It is likely that these long-living, relatively immobile beetles were favoured by the greater stability of the vegetation structure in the extensively grazed plots. Monitoring the ecological assemblage structure provides a more sensitive approach than diversity indices when comparing the impact of grazing and agricultural management but is also robust enough to allow direct comparisons between different geographical locations.

2019 ◽  
Vol 41 (6) ◽  
pp. 535 ◽  
Author(s):  
C. M. Waters ◽  
S. E. McDonald ◽  
J. Reseigh ◽  
R. Grant ◽  
D. G. Burnside

Demonstrating sustainable land management (SLM) requires an understanding of the linkages between grazing management and environmental stewardship. Grazing management practices that incorporate strategic periods of rest are promoted internationally as best practice. However, spatial and temporal trends in unmanaged feral (goat) and native (kangaroo) populations in the southern Australian rangelands can result land managers having, at times, control over less than half the grazing pressure, precluding the ability to rest pastures. Few empirical studies have examined the impacts of total grazing pressure (TGP) on biodiversity and resource condition, while the inability to manage grazing intensity at critical times may result in negative impacts on ground cover, changes in pasture species composition, increased rates of soil loss and reduce the ability for soils to store carbon. The widespread adoption of TGP control through exclusion fencing in the southern Australian rangelands has created unprecedented opportunities to manage total grazing pressure, although there is little direct evidence that this infrastructure leads to more sustainable land management. Here we identify several key indicators that are either outcome- or activity-based that could serve as a basis for verification of the impacts of TGP management. Since TGP is the basic determinant of the impact of herbivory on vegetation it follows that the ability for rangeland pastoral management to demonstrate SLM and environmental stewardship will rely on using evidence-based indicators to support environmental social licence to operate.


1997 ◽  
Vol 8 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Ola Atlegrim ◽  
Kjell Sjöberg ◽  
John Ball

To compare the effects of two tree harvesting methods (clear-cutting and single tree selection felling), spring-occurring ground beetles (Carabidae) were studied by pitfall trapping in northern Sweden. Species abundance, total abundance and Hill's diversity indices were used to compare the ground beetle community in clear-cuts to selectively-logged and to uncut control forests. In addition, to highlight the importance of site replication when evaluating a spatially-variable ecosystem like the boreal forest, we consider how our conclusions might have differed with and without site replication. Results from the two analyses differed considerably, highlighting the importance of site replication in studies offorestry effects in order to increase confidence in the conclusions. Overall, no significant harvest effects were found on the ground beetle community except for a significantly higher abundance of the open habitat species P. assimilis in clear-cuts than in uncut control forests. Our results thus do not support suggestions of an increase in diversity following clear-cutting, but are consistent with previous findings regarding increased abundances of open habitat species and no changes in abundance of forest generalists in clear-cuts. In general, the carabid community in the selection loggings resembled that in the uncut control forest, indicating a low effect of this harvesting method. Based on our analysis, we suggest that future studies of forestry impacts on invertebrates attempt to increase the number of sites evaluated rather than increase the number of samples from a given area.


2016 ◽  
Author(s):  
John E. Hunt ◽  
Johannes Laubach ◽  
Matti Barthel ◽  
Anitra Fraser ◽  
Rebecca L. Phillips

Abstract. Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised, and rotationally-grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass-carbon removed by grazing cows, and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively-managed pasture gained C (NECB = 103 ±42 g C m−2 yr−1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = −13 ±23 g C m−2 yr−1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m−2 yr−1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m−2 yr−1). The irrigated pasture used the total annual water input 37 % more efficiently than the unirrigated pasture to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.


2016 ◽  
Vol 13 (10) ◽  
pp. 2927-2944 ◽  
Author(s):  
John E. Hunt ◽  
Johannes Laubach ◽  
Matti Barthel ◽  
Anitra Fraser ◽  
Rebecca L. Phillips

Abstract. Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB  =  103 ± 42 g C m−2 yr−1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB  =  −13 ± 23 g C m−2 yr−1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m−2 yr−1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m−2 yr−1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.


1994 ◽  
Vol 34 (2) ◽  
pp. 181 ◽  
Author(s):  
DJ Conlan ◽  
BS Dear ◽  
NE Coombes

The impact of grazing intensity and number of grazings was assessed on the growth and seed production of 5 annual pasture legumes [Trifoliunz subterraneum var. subterraneum cv. Karridale, var. brachycalycinum cv. Clare, var. yanninicum cv. Trikkala; Medicago murex (murex medic) cv. Zodiac; Ornithopus compressus L. (yellow serradella) cv. Avila]. There were 7 grazing treatments: an ungrazed control; and 2 grazing intensities (light and heavy), each for 3 periods of grazing (winter, winter-early spring, winter-late spring). Tethered sheep in small experimental plots were used to provide controlled herbage removal across all cultivars through winter and winter-spring grazing. This grazing system resulted in significantly different levels of herbage being present in the light and heavy grazing treatments following each grazing period. Grazing had variable effects on seed production: <35% increase for Trikkala, and no significant effect for Karridale. Both cultivars continued growth and seed production late in the season after grazing pressure was removed on 8 November. Seed yield of Clare was reduced by 46-49% by heavy grazing treatments. Seed yield of murex medic was not significantly affected by grazing, while that of serradella was reduced by 30-55% by grazing late in the season. The seed yield responses show that cultivar and species responses to grazing may be highly variable. Under favourable spring conditions, Trikkala, Karridale, and murex medic can be grazed heavily until late in the season without adversely affecting seed yield, whilst Clare and Avila cannot.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 397
Author(s):  
Virginia Anne Kowal ◽  
Julian Ahlborn ◽  
Chantsallkham Jamsranjav ◽  
Otgonsuren Avirmed ◽  
Rebecca Chaplin-Kramer

Mongolia contains some of the largest intact grasslands in the world, but is vulnerable to future changes in climate and continued increases in the number of domestic livestock. As these are two major drivers of change, it is important to understand interactions between the impact of climate and grazing on productivity of Mongolia’s rangelands and the livelihoods they sustain. We use a gridded, spatially explicit model, the Rangeland Production Model (RPM), to explore the simultaneous and interacting effects of climate and management changes on Mongolia’s rangeland and future livestock production. Comparing the relative impact of temperature, precipitation, and grazing intensity, varied individually and in combination, we find that climatic factors dominate impacts on forage biomass and animal diet sufficiency. Site rainfall strongly mediates the impact of grazing on standing biomass, such that more productive or higher-rainfall sites are more vulnerable to increases in grazing pressure. Gridded simulations covering Mongolia’s Gobi-Steppe ecoregion show that while rangeland biomass is generally predicted to increase under future climate conditions, interactions among spatially varying drivers create strong heterogeneity in the magnitude of change.


2017 ◽  
Vol 1 ◽  
pp. 26-30
Author(s):  
Dilkumar Limbu ◽  
Madan Koirala ◽  
Zhanhuan Shang

Himalayan rangelands have diverse floristic composition and important ecological services. The floristic diversity and composition play an important role in grassland ecosystem regulation. It is different in altitudinal gradient due to grazing intensity, climatic condition and topography. To reveal the vegetation composition values, this work was conducted on August and September 2011 in Tinjure-Milke mountain ridge, Guphapokhari, Nepal. In the present study we have described the impact of altitude on the species richness, species diversity and dispersion behavior of different plants (grasses) in Himalayan rangeland. The values of community indices were observed to be: RD (0.09 to 49.57), RF (3.57 to 14.71), RA (0.23 to 47.59), IVI (3.89 to 111.87), Shannan-Wiener diversity index (1.09 to 2.23) and species diversity evenness (0.12 to 0.19) at the study area, MilkeJaljale, eastern Nepal. Similarly, Species richness (R) value of 8.87 to 11.86 and Simpson dominant index value of 0.12 to 0.42 were observed. All diversity indices were reversed to altitudinal gradient higher the altitudes lower the values. Species richness of all plants showed a unimodal relationship with altitude. Similarly, negative correlation of density and species richness with altitude and slope was recorded.


2002 ◽  
Vol 42 (2) ◽  
pp. 129 ◽  
Author(s):  
G. Taddese ◽  
M. A. Mohamed Saleem ◽  
W. Ayalneh

The impact of grazing on physical properties of Vertisol was studied from 1996 to 2000 in the Ethiopian highlands. The study was conducted at 2 sites with 0–4 and 4–8% slopes at Tero Jemjem watershed in Ginchi, 80 km west of Addis Ababa. The objective of the study was to compare selected soil physical properties at different grazing pressures and slopes. The stocking rate was moderate grazing 1.8 animal-unit months per hectare (1.8 AUM/ha), heavy grazing 3.0 AUM/ha and a control treatment with no grazing. The result showed that heavy grazing pressure removed grass cover, which consequently enhanced soil cracking. Effect of livestock trampling on soil resistance to penetration (indicated by penetrometer readings) was higher in the heavily grazed plots than in non-grazed plots. Penetrometer readings were influenced by soil moisture content. Low moisture content was observed in the heavily grazed plots at both sites. The infiltration of accumulated water to the soil matrix was lower in heavily grazed plots.


2011 ◽  
Vol 38 (4) ◽  
pp. 299 ◽  
Author(s):  
Melissa Pettigrew ◽  
C. Michael Bull

Context Grazing pressure has directly altered and indirectly influenced natural ecosystems worldwide, and has affected and displaced many native species. The endangered pygmy bluetongue lizard Tiliqua adelaidensis is endemic to the mid-north of South Australia. It inhabits remnant native grasslands where it is reliant on the presence of natural spider burrows constructed by lycosid and mygalomorph spiders as refuge sites. These lizards spend the majority of the day associated with their burrow either in the burrow itself or basking at its entrance. The remnant native grasslands of South Australia have endured 200 years of agricultural changes and the introduction of domestic stock has meant that grazing pressure has substantially increased. The vegetation around a burrow is considered to be important in providing shelter for the lizard. However, too much vegetation may reduce basking opportunities and visibility of prey. Stock grazing has been maintained on the majority of sites that contain pygmy bluetongue populations and it is presumed that the lizards can tolerate some form of grazing. However, the level of grazing intensity directly influences the vegetation structure that surrounds the lizard burrows. Aims We aimed to investigate the consequences of severe grazing pressure on the choice of burrows by lizards, and on their burrow related behaviour. Methods We simulated heavy grazing pressure by manually removing aboveground vegetation in the field in replicated quadrats that contained artificial burrows, and by providing bare substrate in half of experimental enclosures in the laboratory. Key results In the field, lizards only occupied the artificial burrows in control quadrats, where vegetation had been left intact. In the laboratory, lizards that occupied both burrows basked for longer at the burrow entrance where vegetation was present. Conclusions Heavy grazing management that results in the majority of vegetation being removed could have a negative impact on pygmy bluetongue lizard recruitment and sustainability. Implications Grazing regimes should be carefully monitored to consider the needs of species that rely heavily on microhabitat structure for their persistence. For the endangered pygmy bluetongue lizard, heavy grazing should be avoided to promote amounts of vegetation suitable to sustain viable populations.


2021 ◽  
pp. 074823372110009
Author(s):  
Dalia Abdel Moneim Kheirallah ◽  
Awatef Mohamed Ali ◽  
Salah Eldein Osman ◽  
Amal Mohamed Shouman

Nickel nanoparticles (Ni-NPs) have advantageous applications in the industry; however, little is known of their adverse effects on biological tissues. In the present study, the ground beetle Blaps polycresta was employed as a sensitive indicator for nickel oxide nanoparticles (NiO-NPs) toxicity. Adult male beetles were injected with six dose levels of NiO-NPs (0.01, 0.02, 0.03, 0.04, 0.05, and 0.06 mg/g body weight). Mortality was reported daily over 30 days under laboratory conditions to establish an LD50. Nickel was detected in the testicular tissues of the beetles using X-ray analysis and transmission electronic microscopy. Beetles treated with the sublethal dose of 0.02 mg/g were selected to observe molecular, cellular, and subcellular changes. Gene transcripts of HSP70, HSP90, and MT1 were found to be increased >2.5-, 1.5-, and 2-fold, respectively, in the treated group compared with the controls. Decreased gene expression of AcPC01, AcPC02, and AcPC04 (≤1.5-, ≤2-, and < 2.5-fold, respectively, vs. controls) also were reported in the treated group. Under light microscopy, various structural changes were observed in the testicular tissues of the treated beetles. Ultrastructure observations using scanning and transmission electron microscopy showed severe damage to the subcellular organelles as well as deformities of the heads and flagella of the spermatozoa. Therefore, the present study postulated the impact of NiO-NPs in an ecological model.


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