Changes in land‐use and climate affect the distribution and diversity of plant and animal species at different spatiotemporal scales. The extent to which species‐specific phenotypic plasticity and ...biotic interactions mediate organismal adaptation to changing environments, however, remains poorly understood. Woody plant expansion is threatening the extent of alpine grasslands worldwide, and evaluating and predicting its effects on herbivores is of crucial importance. Here, we explore the impact of shrubification on the feeding efficiency of Pyrenean chamois (Rupicapra p. pyrenaica), as well as on the three most abundant coexisting domestic ungulate species: cattle, sheep and horses. We use observational diet composition from May to October and model different scenarios of vegetation availability where shrubland and woodland proliferate at the expense of grassland. We then predicted if the four ungulate species could efficiently utilize their food landscapes with their current dietary specificities measuring their niche breath in each scenario. We observed that the wild counterpart, due to a higher trophic plasticity, is less disturbed by shrubification compared to livestock, which rely primarily on herbaceous plants and will be affected 3.6 times more. Our results suggest that mixed feeders, such as chamois, could benefit from fallow landscapes, and that mountain farmers are at a growing economic risk worldwide due to changing land‐use practices and climate conditions.
Climatic and land‐use changes are leading to shrub expansion in alpine grasslands. In this work, we address whether wild and domestic herbivores under varying conditions of resource availability will be able to use efficiently their foraging landscape. We found that “shrubification” affects herbivores differently depending on their feeding preferences and plasticity. Mixed feeders will manage better in fallow landscapes but free‐ranging livestock will be less efficient, highlighting a growing economic risk for mountain livestock farmers worldwide.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
RESUMEN En ecosistemas áridos y semiáridos, las islas de fertilidad o de recursos están conformadas por un mosaico de vegetación arbustiva dispersa, rodeada por una matriz de suelo deteriorada desde ...el punto de vista productivo. Los resultados de diferentes estudios sugieren que los arbustos están directamente relacionados con la dinámica de formación y los patrones de acumulación de nutrientes, controlando funciones a nivel micro y macroecológico. El objetivo de este trabajo es ofrecer un acercamiento al concepto de islas de fertilidad por medio del método de revisión sistemática. El resultado incluyó el análisis de 18 estudios con información relevante acerca de las causas biofísicas y socioecológicas de formación de las islas, la estructura característica de los estratos herbáceo y arbustivo, y el rol espacio-temporal que las comunidades de microorganismos, artrópodos y fauna juegan en su formación. Además, se identificaron las funciones de las islas de fertilidad propuestas en la literatura científica y sus diferentes enfoques. Finalmente, se planteó a futuro el estudio de las islas bajo el enfoque de sistemas complejos y el concepto de resiliencia socioecológica.
In alpine habitats, the seasonally marked climatic conditions generate seasonal and spatial differences in forage availability for herbivores. Vegetation availability and quality during the growing ...season are known to drive life history traits of mountain ungulates. However, little effort has been made to understand the association between plant phenology and changes in the foraging strategies of these mountain dwellers. Furthermore, this link can be affected by the seasonal presence of livestock in the same meadows. The objective of this work was to study the seasonal changes in diet composition of Pyrenean chamois (Rupicapra p. pyrenaica) and its relationship to primary production trends in a Mediterranean alpine environment. Moreover, diet composition in two populations with contrasting livestock pressure was compared in order to study the effect of sheep flocks on the feeding behaviour of chamois. From 2009 to 2012, monthly diet composition was estimated by cuticle microhistological analysis of chamois faeces collected in the eastern Pyrenees. The primary production cycle was assessed by remote sensing, using the Normalized Difference Vegetation Index. Additionally, the diet of sheep sharing seasonally the subalpine and alpine meadows with chamois was analysed. Diet selection of chamois and sheep and their overlap was also assessed. Our results show an intra-annual variation in the diet composition of Pyrenean chamois and demonstrate a strong relationship between plant consumption dynamics and phenology in alpine areas. In addition, Calluna vulgaris, Cytisus spp. and Festuca spp., as well as forbs in the summer, are found to be key forage species for Pyrenean chamois. Furthermore, this study couldn't detect differences between both chamois populations despite the presence of sheep flocks in only one area. However, the detection of a shift in the diet of chamois in both areas after the arrival of high densities of multi-specific livestock suggest a general livestock effect. In conclusion, Pyrenean chamois are well adapted to the variations in the seasonal availability of plants in alpine habitats but could be disturbed by the seasonal presence of livestock. Due to the key plants in their diet, we suggest that population management programmes should focus on the preservation of mixed grasslands composed of patches of shrubs and herbs. The effects of climate change and shrub expansion should be studied as they may potentially affect chamois population dynamics through changes in habitat composition and temporal shifts in forage availability.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Alpine grasslands are essential for carbon sequestration and food supply for domestic and wild herbivores inhabiting mountainous areas worldwide. These biomes, however, are alternatively threatened ...by the abandonment of agricultural and livestock practices leading to a fast-growing shrubification process while other mountain grasslands are suffering from the impacts of overgrazing. The functioning of alpine meadow ecosystems is primarily driven by climatic conditions, land-use legacies and grazing. However, although it is critically important, the role of large herbivores on the aboveground biomass and protein content of palatable plants is poorly understood for most alpine meadows. In this work, we explore the effects of grazing on grassland vegetation at two different spatial and temporal scales in the Eastern Pyrenees, Spain. Remote sensing was used to assess the effect of high and moderate grazing (HG and MG respectively) on grass biomass using the leaf area index (LAI) at the meso-scale (patches between 2.3 and 38.7 ha). We also explored the impact of null (NG), overgrazing (MO, mimicked overgrazing) and high (HG) grazing intensities at local scale setting eighteen 1 m2 exclusion boxes in six meadows (three boxes each) commonly used by domestic and wild ungulates. Historical satellite data showed that LAI values are greater in high than in low grazed areas (HG, mean = 0.66, LG, mean = 0.55). Along the same lines, high and moderate grazing pressures improved biomass production at the local-scale (HG, mean = 590.3 g/m2, MO, mean = 389.3 g/m2 and NG, mean = 110.8 g/m2). Crude protein content reached higher values under MO pressure than under HG pressure. Our results confirm that grazing intensity exerts significant changes on the above-ground biomass production and the protein content of plants consumed by domestic (cattle and horses) and wild ungulates (Southern Chamois, Rupicapra pyrenaica). We can conclude that ungulates sustain biomass and nutritive values of grass exerting a negligible effect on biomass and protein content of woody vegetation. Our results will inform management guidelines to support profitable grazing activities and promote conservation of the open landscapes in the alpine ecosystems under the current global change scenario.
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•We quantified the impact of grazing on biomass production and nutritional value of meadows.•Moderate grazing increases biomass production and protein content of grass.•Biomass and protein contents of woody plants was not affected by grazing.•High grazing reduces biomass production but increases protein content of grass.•Grazing management is important to keep the nutritional value of alpine meadows.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Se implementó un sistema silvopastoril multiestrato (SSPm) en una zona de bosque húmedo tropical (bh-T), en el Municipio de Tumaco, Departamento de Nariño, Colombia, para medir su impacto en la ...diversidad florística en los sistemas ganaderos, la mesofauna edáfica en el Sistema Silvopastoril y la producción y calidad de la oferta alimentaria, comparado con un sistema convencional (SC) basado en pastizales. Adicionalmente, se realizó una caracterización del proceso de regeneración natural en el Sistema Silvopastoril, a través de análisis de estructura horizontal, abundancia de especies, dominancias absolutas y frecuencia. La composición y diversidad florística se determinó mediante los índices de Shannon-Wiener, Margalef y de Simpson. Los arreglos silvopastoriles se evaluaron con un diseño experimental en bloques completos al azar con arreglo en parcelas divididas. El análisis del suelo reportó una textura arcilloso-arenoso, relativamente pesado, con una densidad aparente de 1,04 y 1,12 g cm3 en el Sistema Silvopastoril y convencional respectivamente. Los contenidos de N (0,07%), K (0,43 cmol kg-1) y MO (2,04%) resultaron mayores en el SSPm, hubo mayor presencia de individuos descomponedores de materia orgánica, como lombrices, en el Sistema Silvopastoril, en ambas épocas. Se evidenció cómo los sistemas silvopastoriles favorecen la producción de biomasa comestible (17,82 del SSPm frente a 11,97 Ton MS ha-1 año-1 en el SC). Se encontró un total de 38 especies entre herbáceas, arbustivas y arbóreas, pertenecientes a 25 familias y 35 géneros, siendo las familias más representativas Fabaceae, Urticaceae y Solanaceae. Se puede concluir que este tipo de sistemas representa una alternativa favorable para la ganadería en región húmeda.
•Enhanced Vegetation Index (EVI) was used to assess diet composition and quality in Pyrenean chamois.•In spring and winter the EVI was negatively related to diets low in fibre and Calluna but ...positively to diets high in nitrogen, Festuca, Forbs and Trifolium.•During the summer season, the EVI was not related to diet components of chamois.•Remote sensing can be used as a tool for monitoring nutritional quality of large herbivore populations in management programmes.
In recent years, the use of satellite-derived vegetation indices has become a powerful tool to collect information on vegetation dynamics in a broad range of ecosystems worldwide. However, the utility of these indices as indicators of the diet composition and quality of herbivore mammals has not yet been established. This work focuses on exploring such relationships analysing four years of records of monthly Enhanced Vegetation Index (EVI, a MOD13 satellite-derived index) and diet composition and quality of two populations of chamois (Rupicapra pyrenaica pyrenaica) in the Eastern Pyrenees (Spain). Our results revealed that 68.4% and 53.3% of diet composition and quality of chamois can be explained by EVI values in the green-up season (spring) and green senescence (winter season), respectively. In both periods, EVI was related mainly to diets low in fibre (cellulose, hemicellulose and lignin) and heather (Calluna vulgaris) and high in nitrogen due to the consumption of Festuca, Forbs and Trifolium. During the summer season however, the EVI was not significantly related to diet components of chamois. A significant inter-year variability in the diets of the chamois was also observed. To conclude, remote sensing is appropriate to assess temporal variations in dietary components of mountain ungulates, and could be used as a component of monitoring large herbivore populations in management programmes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Faecal nitrogen (FN) has been used as a proxy for diet quality for over half a century.•But FN is often more related to diet digestibility (fibre) than to dietary nitrogen.•Gastrointestinal ...nematodes can also increase FN.•We performed and experiment for exploring the role of both factors on FN in a small ruminant.•The importance of considering both dietary fibre and gastrointestinal nematodes when using FN for wildlife nutrition monitoring was confirmed.
Faecal nitrogen (FN) – the combination of metabolic nitrogen and residual food nitrogen – has been used as a proxy for diet quality in wild and domestic ruminants for over half a century. However, a common misconception in some of these studies is that FN is a direct proxy for dietary N, in spite of experimental evidence that links FN to general diet digestibility. Additionally, gastrointestinal nematodes (GIN) can alter N metabolism and increase FN by various mechanisms. To clarify the role of dietary N, fibre and GIN as a factor in FN excretion, 10 naturally parasitised sheep were fed two different isocaloric diets (LPF: low-protein, low-fibre; HPF: high-protein, high-fibre). One month after these diets began, a single anthelmintic treatment was applied to remove GIN, after which the sheep were kept on the same diet for an additional 2 weeks. Throughout the experiment, individual faecal samples were obtained to estimate both FN and GIN intensity (using faecal egg counts, FEC). In addition, two blood samples were taken before and after deworming to measure serum total protein concentrations (TP) as a proxy for protein absorption. In spite of the difference in dietary protein, FN was higher on an LPF diet, supporting the overall digestibility concept. The influence of GIN on FN was later revealed by the anthelmintic treatment, which led to a decrease of FEC and FN in both dietary groups. Serum total protein showed a slight but non-significant increase in both groups after the anthelmintic treatment. Our study supports not only the concept that FN is a proxy for diet digestibility, and not directly for dietary N, but also that gastrointestinal nematodes limit its use as a proxy for diet quality in ruminants, especially under high parasite loads (e.g., 1000 faecal eggs per gram of faeces). Such limitations should be considered before using FN for wildlife nutrition monitoring. Some recommendations are given to avoid misinterpretations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Monitoring nutritional status of wildlife is key to understanding the population response to changes in food availability. Several direct and indirect methods have been proposed for such purposes, ...but faecal nitrogen (FN) is by far the most commonly used indirect non-invasive indicator of free-ranging ruminant diet quality. In this work, two methods were used to estimate the FN content in 291 pellet samples of Pyrenean chamois (
Rupicapra pyrenaica pyrenaica
) collected during a 2-year period (May 2009 to May 2011) in two chamois populations from the Catalan Pyrenees, Spain: the Dumas LECO analyzer and near-infrared reflectance spectroscopy (NIRS). In order to optimize further FN estimations we performed three different NIRS calibrations: (1) general, across year, season and populations; (2) population-specific; and (3) season-specific, i.e., different periods of vegetation growth. FN ranged from 1.66 % to 2.85 % (dry matter basis) and was higher in the main vegetation growing season than in winter. Concerning NIRS calibration, our study confirmed that FN of Pyrenean chamois can be accurately determined by NIRS, since the general calibration was accurate enough to predict FN. It is concluded that NIRS represents a non-destructive, emission-free and low-cost analytical technique which may reduce the use of conventional laborious methods for estimating FN in long-term wildlife monitoring.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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