Sheep grazing in the North Atlantic region: A long-term perspective on environmental sustainability

Long-term changes in herbivore community and vegetation impact of wild and domestic herbivores across Iceland

Changes in wild and domestic herbivore populations significantly impact extensive grazing systems, particularly in low productive environments, where increasing wild herbivore populations are perceived as a threat to farming. To assess the magnitude of these changes in Iceland, we compiled time series on herbivore populations from 1986 to 2020 and estimated changes in species densities, metabolic biomass, and consumption of plant biomass in improved lands and unimproved rangelands. We compared estimates of consumption rates to past and present net primary production. Overall, the herbivore community composition shifted from livestock to wildlife dominated. However, wild herbivores only contributed a small fraction (14%) of the total herbivore metabolic biomass and consumption (4-7%), and livestock dominated the overall herbivore biomass. These insights highlight the necessity of developing improved local integrated management for both wild and domestic herbivores where they coexist.

Agriculture in the Baksan Gorge of the Central Caucasus, Kabardino-Balkaria, Russia

No agriculture is possible without soil. This article reviews available data on the soils of the Baksan Gorge located in the Kabardino-Balkarian Republic, Russia. The research objective was to collect and analyze information on the soil composition and crop yields in this region of the Central Caucasus. The review covered the last five years of scientific publications cited in Scopus, Web of Science, and Elibrary. It also featured contemporary and archival documents on the soil composition and periglacial agriculture in the Baksan Gorge. The agriculture and cattle breeding started in the Central Caucasus in the first millennium BC when the local peoples began to develop these lands as highland pastures and, subsequently, for agricultural farming. During the second millennium BC, crop production became one of the most important economic sectors in the Central Caucasus. Corn, barley, wheat, and millet were the main agricultural crops in the Baksan Gorge. Millet has always been a traditional Kabardian crop, and millet farming occupied the largest flatland areas. Barley was the staple crop in the highlands. Currently, the list of local staple crops includes corn, wheat, and sunflower. Barley, oats, peas, potatoes, vegetables, berries, nuts, grapes, and annual herbs are also popular. The past fifteen years have seen an extensive development of intensive horticulture in the Baksan Gorge. Agricultural ecology and production problems depend on the localization of agriculture in the Central Caucasus. This research reviewed data on the effect of soil composition on the yield and value of agricultural crops in the Baksan Gorge of the Central Caucasus.

Herbivore species coexistence in changing rangeland ecosystems: First high resolution national open-source and open-access ensemble models for Iceland

Rangeland ecosystems are changing worldwide with the abandonment of extensive pastoralism practices and greater interest for species coexistence. However, the lack of compiled data on current changes in the abundance and distribution of herbivores challenges rangeland management decisions. Here we gathered and made available for the first time the most extensive set of occurrence data for rangeland herbivores in Iceland in an Open Access framework for transparent and repeatable science-based decisions. We mapped fine scale species distribution overlap to identify areas at risk for wildlife-livestock conflict and overgrazing. Nationwide and long term (1861-2021) occurrence data from 8 independent datasets were used alongside 11 predictor raster layers ("Big Data") to data mine and map the distribution of the domestic sheep (Ovis aries), feral reindeer (Rangifer tarandus tarandus), pink-footed geese (Anser brachyrhynchus), and rock ptarmigan (Lagopus muta islandorum) over the country during the summer. Using algorithms of Maxent in R, RandomForest, TreeNet (stochastic gradient boosting) and MARS (Splines) in Minitab-SPM 8.3, we computed 1 km pixel predictions from machine learning-based ensemble models. Our high-resolution models were tested with alternative datasets, and Area Under the Curve (AUC) values that indicated good (reindeer: 0.8817 and rock ptarmigan: 0.8844) to high model accuracy (sheep: 0.9708 and pink-footed goose: 0.9143). Whenever possible, source data and models are made available online and described with ISO-compliant metadata. Our results illustrate that sheep and pink-footed geese have the greatest overlap in distribution with potential implication for wildlife-livestock conflicts and continued ecosystem degradation even under diminishing livestock abundance at higher elevation. These nationwide models and data are a global asset and a first step in making available the best data for science-based sustainable decision-making about national herbivores affecting species coexistence and environmental management.

Mapping cumulative pressures on the grazing lands of northern Fennoscandia

Traditional grazing areas in Europe have declined substantially over the last century. Specifically, in northern Fennoscandia, the grazing land is disturbed by cumulative land-use pressures. Here we analysed the configuration of the grazing land for reindeer and sheep in northern Fennoscandia in relation to the concurrent land-use pressures from tourism, road and railway networks, forestry, industrial and wind energy facilities, together with predator presence and climate change. Our results show that 85% of the region is affected by at least one land-use pressure and 60% is affected by multiple land-use pressures, co-occurring with predator presence and rising temperatures. As such, a majority of the grazing land is exposed to cumulative pressures in northern Fennoscandia. We stress that, if the expansion of cumulative pressures leads to grazing abandonment of disturbed areas and grazing intensification in other areas, it could irreversibly change northern vegetation and the Fennoscandian mountain landscape.

Sustainability of the grazing and feeding resources for sheep during the non-migratory period in Jammu and Kashmir

The objective of the study was to evaluate the sustainability of the grazing and feeding resources of the sheep in Kashmir, India. The study was conducted in the Ganderbal District of Kashmir to evaluate sustainability, along with the scenario of grazing pattern and feeding system of the sheep during the non-migratory period. The district was divided into three production zones based on altitude, i.e., zone I (high altitude), zone II (medium altitude), and zone III (low altitude). A total of 360 sheep farmers were interviewed from the three zones that consist of 9 blocks, with 40 sheep farmers interviewed from each block. Majority of the sheep farmers (75.00%) follow a semi-migratory type of production system, use forest, and low-mountain areas for grazing purposes (48.88%) and were having medium to high availability of grazing lands. The main feeding source available to majority of the sheep farmers (60.00%) was found to be crop residues and fodder grasses, with local markets (60.00%) and fellow farmers (71.11%) being the main source of procuring concentrates and fodders. Hybrid entropy and TOPSIS method were used for the evaluation of sustainability of grazing and feeding system in the area. The most influencing factors for sustainability of grazing pattern and feeding source were found to be production system followed and the major feed sources available respectively. Most of the variables included in the grazing system were ideally best in zone I and of feeding system were found to be ideally best in zone III. There is a need for improvement in the parameters of the grazing pattern in zone III, i.e., in low-altitude areas or planes where grazing lands are shrinking at an alarming rate. The parameters under the feeding system need due consideration in zone I, i.e., in the high altitudes where the socio-economic situation of the people is comparatively poor than the other two zones.

Identification, Superantigen Toxin Gene Profile and Antimicrobial Resistance of Staphylococci Isolated from Polish Primitive Sheep Breeds

The study aimed to analyze staphylococcal microbiota of the nasal cavity of the primitive sheep breeds Polish Świniarka and Wrzosówka kept on the same ecological farm. The research included the identification of staphylococcal species, evaluation of the prevalence of genes encoding enterotoxins, staphylococcal enterotoxin-like proteins, exfoliative toxins, toxic shock syndrome toxin 1, and detection of antimicrobial resistance. From 61 swab samples gathered from Świniarka (33) and Wrzosówka (28) healthy sheep, 127 coagulase-negative staphylococci (CoNS) were isolated. Based on PCR-RFLP analysis of the gap gene using AluI and HpyCH4V enzymes, the isolates were identified as: Staphylococcus xylosus (33.9%), S. equorum (29.1%), S. arlettae (15%), S. warneri (9.4%), S. lentus (7.9%), S. succinus (3.9%) and S. sciuri (0.8%). Three of these species, S. lentus, S. succinus, and S. sciuri, were detected only from the Świniarka breed. It was found that 77.2% of isolates harbored from 1 to 7 out of 21 analyzed genes for superantigenic toxins. The greatest diversity of toxin genes was recorded for S. equorum (16 different genes). The most prevalent gene was ser (40.2%). The incidence and number of resistances to antimicrobials were found to be bacterial species but not sheep breed dependent. The highest percentage of resistance was found for S. sciuri. The most frequent resistance was observed to clindamycin (45.7%). The findings of this study prove that toxigenic and antimicrobial resistant CoNS can colonize the nasal cavity of healthy sheep.

Legacy effects of herbivory on treeline dynamics along an elevational gradient

Treelines are expected to expand into alpine ecosystems with global warming, but herbivory may delay this expansion. This study quantifies long-term effects of temporally varying sheep densities on birch recruitment and growth in the treeline ecotone. We examined treeline ecotone successional trajectories and legacy effects in a replicated experimental setup, where enclosures were present for 14 years with three different sheep densities (0, 25, 80 sheep km⁻²). Before and after the enclosures were present, the site had an ambient sheep density of 20–25 km⁻². We sampled field data 4 years after enclosure removal and compared these to data sampled 8 and 9 years after enclosure erection. We sampled data on birch browsing pressure, birch distribution across life-stages (recruits, saplings, and mature trees), and birch annual radial growth. Fourteen years of increased or decreased sheep density had observable legacy effects depending on birch life-stage. Birch recruit prevalence decreased in areas, where sheep were reintroduced after being absent for 14 years. For the same areas, sapling and mature tree prevalence increased, indicating that these areas have entered alternative successional trajectories compared to areas, where sheep were present the whole time. Birch annual radial growth showed a lag effect of 2 years after enclosure removal, with growth decreasing in areas where sheep had been absent for 14 years and increasing where sheep densities were high. Thus, decadal-scale absences of herbivores can leave legacy effects due to increased numbers of trees that have high resistance to later-introduced herbivore browsing.

Trust in large carnivore science in Norway

Large carnivores are controversial species, and associated conflicts between stakeholders with opposing views on large carnivores are observed across the globe. Social trust, the public’s willingness to rely on those responsible for developing policies, has gained much attention regarding the acceptance of large carnivores and large carnivore management. However, trust in large carnivore science has not received as much consideration. In Norway, administrative management authorities are responsible to execute the political framework decided by the Norwegian Parliament while basing their decisions on recommendations from large carnivore science. As large carnivore science is the main knowledge provider for monitoring and measures implemented in management decisions to achieve viable carnivore populations, trust in science is crucial. Yet, scientific information is often challenged. As attitude studies show a tendency for the wider general public to be more positive towards large carnivores than people most adversely affected, we wanted to examine whether the trust in large carnivore science follows the same pattern. We used a geographically stratified sample of 2110 respondents, five respondents from each municipality in Norway, to model how trust varies across the sample. Our results indicate that elderly men, people with lower education, those who have experienced loss of livestock to carnivores associate with lower trust in large carnivore science. Lower trust was also found among big game hunters and people who fear large carnivores. This knowledge could help to guide targeted science communication and contribute to a more comprehensive understanding of cognitions important for management of conflicts involving large carnivores.

Herbivory and climate as drivers of woody plant growth: Do deer decrease the impacts of warming?

Vegetation at ecotone transitions between open and forested areas is often heavily affected by two key processes: climate change and management of large herbivore densities. These both drive woody plant state shifts, determining the location and the nature of the limit between open and tree or shrub-dominated landscapes. In order to adapt management to prevailing and future climate, we need to understand how browsing and climatic factors together affect the growth of plants at biome borders. To disentangle herbivory and climate effects, we combined long-term tree growth monitoring and dendroecology to investigate woody plant growth under different temperatures and red deer (Cervus elaphus) herbivory pressures at forest-moorland ecotones in the Scottish highlands. Reforestation and deer densities are core and conflicting management concerns in the area, and there is an urgent need for additional knowledge. We found that deer herbivory and climate had significant and interactive effects on tree growth: in the presence of red deer, pine (Pinus sylvestris) growth responded more strongly to annual temperature than in the absence of deer, possibly reflecting differing plant-plant competition and facilitation conditions. As expected, pine growth was negatively related to deer density and positively to temperature. However, at the tree population level, warming decreased growth when more than 60% of shoots were browsed. Heather (Calluna vulgaris) growth was negatively related to temperature and the direction of the response to deer switched from negative to positive when mean annual temperatures fell below 6.0°C. In addition, our models allow estimates to be made of how woody plant growth responds under specific combinations of temperature and herbivory, and show how deer management can be adapted to predicted climatic changes in order to more effectively achieve reforestation goals. Our results support the hypothesis that temperature and herbivory have interactive effects on woody plant growth, and thus accounting for just one of these two factors is insufficient for understanding plant growth mechanics at biome transitions. Furthermore, we show that climate-driven woody plant growth increases can be negated by herbivory.

Clinging on to alpine life: Investigating factors driving the uphill range contraction and population decline of a mountain breeding bird

Climate change and anthropogenic nitrogen deposition are widely regarded as important drivers of environmental change in alpine habitats. However, due to the difficulties working in high-elevation mountain systems, the impacts of these drivers on alpine breeding species have rarely been investigated. The Eurasian dotterel (Charadrius morinellus) is a migratory wader, which has been the subject of uniquely long-term and spatially widespread monitoring effort in Scotland, where it breeds in alpine areas in dwindling numbers. Here we analyse data sets spanning three decades, to investigate whether key potential drivers of environmental change in Scottish mountains (snow lie, elevated summer temperatures and nitrogen deposition) have contributed to the population decline of dotterel. We also consider the role of rainfall on the species' wintering grounds in North Africa. We found that dotterel declines-in both density and site occupancy of breeding males-primarily occurred on low and intermediate elevation sites. High-elevation sites mostly continued to be occupied, but males occurred at lower densities in years following snow-rich winters, suggesting that high-elevation snow cover displaced dotterel to lower sites. Wintering ground rainfall was positively associated with densities of breeding males two springs later. Dotterel densities were reduced at low and intermediate sites where nitrogen deposition was greatest, but not at high-elevation sites. While climatic factors explained variation in breeding density between years, they did not seem to explain the species' uphill retreat and decline. We cannot rule out the possibility that dotterel have increasingly settled on higher sites previously unavailable due to extensive snow cover, while changes associated with nitrogen deposition may also have rendered lower lying sites less suitable for breeding. Causes of population and range changes in mountain-breeding species are thus liable to be complex, involving multiple anthropogenic drivers of environmental change acting widely across annual and migratory life cycles.

The Social Metabolism of Quiet Sustainability in the Faroe Islands

This paper investigates the interrelations between social metabolism and socio-ecological sustainability in the Faroe Islands in a long-term perspective. It traces the trajectory and changes in socio-metabolic configurations from the time of settlement until today and shows how social metabolism has increased to very high per capita levels during the past century. The analysis departs from the recognition that a decrease in social metabolism, i.e., a net reduction in throughput of natural resources in human economies, is necessary in order to curb the impending ecological crisis. It is argued that parallel to the growth oriented formal Faroese economy, economic food-provisioning practices rooted in the traditional, and ecologically sustainable, land management system continue to be practiced by Faroese people. These practices can be conceptualized as practices of so-called “quiet sustainability” and their contribution is estimated in bio-physical metrics of weight. The analysis shows that practices of “quiet sustainability” contribute significant quantities of certain food items to the local population thereby enhancing food security and food sovereignty. Moreover, these practices are an integral element in the biocultural diversity, which has constituted the Faroe Islands for close to two millennia. Therefore, they should be considered real alternatives to import-based consumption and taken into account in sustainability discourse and policy to a higher degree than is currently the case.

Long-term changes in northern large-herbivore communities reveal differential rewilding rates in space and time

Herbivores have important impacts on ecological and ecosystem dynamics. Population density and species composition are both important determinants of these impacts. Large herbivore communities are shifting in many parts of the world driven by changes in livestock management and exploitation of wild populations. In this study, we analyse changes in large herbivore community structure over 66 years in Norway, with a focus on the contribution of wildlife and livestock. We calculate metabolic biomass of all large-herbivore species across the whole region between 1949 and 2015. Temporal and spatial patterns in herbivore community change are investigated and we test hypotheses that changes in wildlife biomass are driven by competition with livestock. We find that total herbivore biomass decreased from 1949 to a minimum in 1969 due to decreases in livestock biomass. Increasing wild herbivore populations lead to an increase in total herbivore biomass by 2009. Herbivore communities have thus reverted from a livestock dominated state in 1949 (2% of large herbivore metabolic biomass comprised of wildlife species) to a state with roughly equal wildlife and livestock (48% of metabolic biomass comprised of wildlife species). Declines in livestock biomass were a modest predictor of wildlife increases, suggesting that competition with livestock has not been a major limiting factor of wild herbivore populations over the past decades. Instead there was strong geographic variation in herbivore community change, with milder lowland regions becoming more dominated by wild species, but colder mountain and northern regions remaining dominated by livestock. Our findings indicate that there has been notable rewilding of herbivore communities and herbivore-ecosystem interactions in Norway, particularly in milder lowland regions. However, Norwegian herbivores remain mostly regulated by management, and our findings call for integrated management of wild and domestic herbivores.