Alternativas alimentarias para la producción pecuaria del trópico alto de Nariño

La universidad es el escenario propicio para que las inquietudes académicas y científicas tomen forma en sus diferentes modalidades, una de las cuales y quizás la más emblemática, resulta ser el libro, en la medida en que los libros son testimonios claros de la tarea de los maestros y el legado que dejan a sus discípulos. La universidad es el escenario propicio para que las inquietudes académicas y científicas tomen forma en sus diferentes modalidades, una de las cuales y quizás la más emblemática, resulta ser el libro, en la medida en que los libros son testimonios claros de la tarea de los maestros y el legado que dejan a sus discípulos. El libro Alternativas Alimentarias para la Producción Pecuaria del Trópico Alto de Nariño, escrito por los profesores de la Universidad de Nariño, José Edmundo Apráez Guerrero y Arturo Leonel Gálvez Cerón, zootecnistas de profesión y doctorados en nutrición animal y producción animal, es una contribución valiosa para apoyar la realidad socioeconómica y productiva del sector agrario de los “Andes altos” de Nariño y de regiones similares, porque pone en evidencia el potencial de los recursos vegetales que prosperan en estas condiciones. Ellos han visto lo que otros quizás han pasado por alto y así coinciden con el criterio de Morin, quien considera que lo “más difícil de ver es lo evidente”. Los autores quieren decirnos con su obra, ahí está disponible toda esta biodiversidad vegetal que ha sido estudiada y valorada científicamente durante varias décadas y por eso, con su análisis y compilación, animan a la utilización de esta oferta de la naturaleza

Dieta del rebeco en el pirineo oriental : efectos del ganado doméstico y de los parásitos /

A la portada: Universidade de Aveiro. Departamento de Biologia. Unidade vida Selvagem i SEFAS, Servei d'Ecopatologia de Fauna SalvatgeEn el campo de la ecología trófica, un tema prioritario es estudiar cómo el solapamiento de dietas conduce a procesos de coexistencia o de competencia. Para conocer cuál es el estado de conocimiento actual sobre esta cuestión, realizamos una revisión bibliográfica en el buscador científico Thomson Reuters Web of Knowledge y en la bibliografía especializada no indexada escrita en castellano. La revisión se centró en trabajos sobre las familias Bovidae, Equidae y Cervidae. En concreto, evaluamos cómo la disponibilidad de recursos, el hecho de que las especies perteneciesen a una familia de ungulados concreta, y su naturaleza salvaje o doméstica, influyen sobre el solapamiento en la dieta. Para analizar la información usamos una selección de modelos basada en el criterio de Akaike. El solapamiento fue máximo cuando conviven bóvidos con equinos, y mínimo cuando lo hacen cérvidos con bóvidos. La disponibilidad de alimento tuvo poca importancia sobre el solapamiento, y el hecho de que las especies sean salvajes o domésticas no tuvo ninguna influencia. Para comprender en qué medida el solapamiento implica competencia, serán necesarios estudios que evalúen cómo los cambios en los hábitos alimenticios de especies en simpatría influyen sobre la aptitud biológica de las poblaciones (fitness).A cornerstone in the field of trophic ecology is understanding whether diet overlap leads to coexistence or competence. In order to know the current understanding about this, we performed a literature review in both the Thomson Reuters Web of Knowledge and other specific journals written in Spanish. This review was focused on theBovidae, Equidae, and Cervidae families. Concretelly, our objective was to explored whether food availability, the co-occurrence of ungulates belonging to specific taxa and the fact of being wild or domestic influenced diet overlap. Model selection was based on the Akaike information criteria. Diet overlap peaked between bovidae and equidae members, but was low between bovids and equids. Food availability had few influence on diet overlap and the fact of being wild or domestic had no effect. Further research on the impact of dietary shifts due to species co-occurrence will be required to understand whether diet overlap results in competition for food

Seasonal diet composition of Pyrenean chamois is mainly shaped by primary production waves

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

Dieta del rebeco en el pirineo oriental: efectos del ganado doméstico y de los parásitos

En el campo de la ecología trófica, un tema prioritario es estudiar cómo el solapamiento de dietas conduce a procesos de coexistencia o de competencia. Para conocer cuál es el estado de conocimiento actual sobre esta cuestión, realizamos una revisión bibliográfica en el buscador científico Thomson Reuters Web of Knowledge y en la bibliografía especializada no indexada escrita en castellano. La revisión se centró en trabajos sobre las familias Bovidae, Equidae y Cervidae. En concreto, evaluamos cómo la disponibilidad de recursos, el hecho de que las especies perteneciesen a una familia de ungulados concreta, y su naturaleza salvaje o doméstica, influyen sobre el solapamiento en la dieta. Para analizar la información usamos una selección de modelos basada en el criterio de Akaike. El solapamiento fue máximo cuando conviven bóvidos con equinos, y mínimo cuando lo hacen cérvidos con bóvidos. La disponibilidad de alimento tuvo poca importancia sobre el solapamiento, y el hecho de que las especies sean salvajes o domésticas no tuvo ninguna influencia. Para comprender en qué medida el solapamiento implica competencia, serán necesarios estudios que evalúen cómo los cambios en los hábitos alimenticios de especies en simpatría influyen sobre la aptitud biológica de las poblaciones (fitness).A cornerstone in the field of trophic ecology is understanding whether diet overlap leads to coexistence or competence. In order to know the current understanding about this, we performed a literature review in both the Thomson Reuters Web of Knowledge and other specific journals written in Spanish. This review was focused on theBovidae, Equidae, and Cervidae families. Concretelly, our objective was to explored whether food availability, the co-occurrence of ungulates belonging to specific taxa and the fact of being wild or domestic influenced diet overlap. Model selection was based on the Akaike information criteria. Diet overlap peaked between bovidae and equidae members, but was low between bovids and equids. Food availability had few influence on diet overlap and the fact of being wild or domestic had no effect. Further research on the impact of dietary shifts due to species co-occurrence will be required to understand whether diet overlap results in competition for food

Islas de fertilidad: una revisión sistemática de su estructura y operación

ABSTRACT In arid and semi-arid ecosystems fertility or resource islands are made up of a mosaic of scattered shrub, surrounded by a de-teriorated soil matrix from the production point of view. Results of several studies suggest that the shrubs are directly related with the dynamics of formation and nutrient accumulation patterns, controlling functions at a micro and macro-ecological level. The aim of this document is to provide an approach to the concept of fertility islands through the systematic revision method. The result included an analysis of 18 studies with relevant information on biophysical and socio-ecological formation causes, the characteristic structure of the herbaceous and shrub layers, and the spatio-temporal role of communities of microorganisms, arthropods and fauna. The functions of the islands of fertility proposed in the scientific literature and their different approaches were identified. In conclusion, the study of the islands under the complex system approach and the socio-ecological resilience concept were proposed for the future.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

IMPLEMENTACIÓN Y EVALUACIÓN DE UN SISTEMA SILVOPASTORIL EN EL CHOCÓ BIOGEOGRÁFICO COLOMBIANO

Was implemented a multi-layer Silvopastoral system (mlSPS) in an area of Tropical humid forest in the municipality of Tumaco, Department of Nariño, to measure its impact on the diversity of flora in livestock systems, the edaphic mesofauna, and the production and quality of the food supply compared to conventional system (CS), based grass monoculture. In addition, a characterization of the natural regeneration process was performed in the silvopastoral system, through horizontal structure analysis, abundance of species, absolute dominance and frequency. The composition and floristic diversity it was determined by the indices of Shanon-Wiener and of Simpson. Soil analysis showed relatively heavy clay-sandy soils, with an apparent density of 1.04 and 1.12 g cm-3 in the Silvopastoral System and conventional respectively. The levels of N (0.07%), K (0.43 cmol kg-1) and organic matter (2.04%) were higher in the mlSPS. There were more OM decomposer individuals, such as worms in the Silvopastoral System in both seasons. It was evidenced that the silvopastoral systems increase the production of edible biomass (17.82 of the mlSPS compared to 11.97 Tn DM ha-1 year-1 in the CS). A total of 38 herbaceous, shrub and arboreal species were found, belonging to 25 families and 35 genera; the most representative families were: Fabaceae, Urticaceae and Solanaceae. It is concluded that multi-stratum silvopastoral systems represent a good alternative for tropical humid forest livestock.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

Different effects of alpine woody plant expansion on domestic and wild ungulates

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

Gastrointestinal nematodes and dietary fibre: two factors to consider when using FN for wildlife nutrition monitoring

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