•We compare trophic behaviour and social structure of insular wild and feral goats.•We observed similar behaviour pattern apart from some seasonal variations.•Feral goats apparently have a higher ...gregarious behaviour than wild ones.•Differences suggested that the wild ecotype is better adapted to the vegetation.
The aim of this study was to compare the trophic behaviour and the social structure of Majorcan wild goats and feral goats present in the island of Majorca. The former are descendants of an ancestral goat ecotype introduced in the island in the late Neolithic, whereas feral goats come from domestic forms introduced recently from the Iberian Peninsula. The study was conducted in four localities of the Serra de Tramuntana, a mountain range located in the northwest of the island of Majorca. Behavioural data were collected in three seasons, summer, winter and spring of 2011–2013, and when goat activity is at its peak, i.e., 3h after dawn and before dusk. The following variables were recorded: group composition (males, females, and kids) and activity (feeding, walking, resting, and watching). The proportion of time spent on each activity and their frequency were obtained from focal samples. Multivariate analyses of variance (MANOVA) were used to simultaneously analyse the activity variables. A total of 155 observations of 85 herds were registered throughout the study. A similar behaviour pattern has been observed in this study for the two goat ecotypes, feral and wild, apart from some seasonal variations in feeding and resting activities. In summer, feral goats showed higher feeding efforts (duration and frequency) than wild goats; this might be related to a lower efficiency obtaining feeding resources by the former, whereas wild goats, that have inhabited the island for millennia, coexisting with vegetation in periods of lower forage abundance and quality, would be more efficient herbivores during restrictive periods. Average herd size for both ecotypes is smaller than that recorded for domestic goat herds, suggesting a relatively low browsing damage compared to the latter. Also, feral goats apparently have a higher gregarious behaviour than wild ones, which might relate to their domestic origin. Currently, the management of goats on the island is based on maintaining the wild ecotype and eradicate the feral one, whose impact on vegetation is supposedly worse. However, our results show a similar trophic behaviour by both ecotypes, so that their impact on vegetation should also be expected to be similar, indicating that this argument has not enough scientific basis.
Buxus balearica Lam., Ephedra fragilis Desf., and Juniperus oxycedrus L. are three Pre-Mediterranean shrubs that have become scarce in the Balearic Islands probably due to a climatic change and the ...anthropogenic activities during the second half of the Holocene. In addition, an endemic artiodactyl, Myotragus balearicus, exerted browsing pressure on these species for thousands of years, and after it disappeared domestic goats were introduced by humans. Adaptations that enable these plants to resist grazing are structural or chemical; however, there is no information about whether their defenses are only constitutive or also inducible. Currently, the mountain ranges of Majorca Island are extensively occupied by feral goats, and a possible increase in the stocking rates could affect the survival of these plant species. The aim of this study was to evaluate and compare the effects of simulated severe browsing on the re-growth capacity and chemical composition of these species in order to determine their tolerance to herbivory. We sampled and compared structural and chemical variables of saplings submitted to two pruning intensities for each species.
The results showed that all three species could maintain their growth rate and biomass ratios under simulated herbivory. Sprout production was also stimulated in all them. E. fragilis and B. balearica increased phenolic content after pruning, and E. fragilis also increased the condensed tannins. Pruning treatments did not trigger induction of phenolic content in J. oxycedrus, which could be considered as a constitutive defense. It is noteworthy that alkaloids in E. fragilis decreased with the treatments, which may contribute to preventing a possible addiction to these compounds, and thus reduce browsing damage.
The responses induced by pruning show that these species are very tolerant to a level of herbivory, which could indicate a good adaptation to browsing pressure, exerted since the Pleistocene by Myotragus balearicus, and followed by goats during the last millennia. This is especially relevant in Mediterranean islands, such as the Balearic Islands, where practices for conserving relict plant species are based on feral herbivore exclusion.
•An increase of feral goat stocking rates in Mallorca could affect the survival of some shrubs.•The effects of simulated browsing on the re-growth and chemical composition of these species was studied.•Buxus balearica, Ephedra fragilis and Juniperus oxycedrus maintained their growth rate and biomass under simulated herbivory.•The responses induced by pruning show that these species are very tolerant to a level of herbivory.•That tolerance indicates a good adaptation to browsing pressure, exerted since the Pleistocene by Myotragus balearicus.
We raised the necessity of an effectively and fast transfer of the results obtained by researchers to inhabitants of the natural areas. This necessity is more peremptory in the case of the developing ...countries, and when researches work in the management of natural resources. It is the case of the research group of the Laboratory of Ecology of Communities at the UNAM, which simultaneously develops diverse projects of research to analyze the human effect on natural ecosystems and generated models of sustainable development. The area of research is mainly the Reserve of the Biosphere of Tehuacán-Cuicatlán, a zone of high biological and cultural diversity, but also of high social marginalization. In this manuscript we present two examples: the extensive goat ranch and the use of Agave species for mezcal production. We show how scientific studies and cooperative work with human communities inhabiting the zone, we improve the use and conservation of natural resources. Planteamos la necesidad de transferir rápida y eficazmente los resultados de investigación a habitantes de las zonas naturales de estudio. Esta necesidad es más perentoria en el caso de los países en vías de desarrollo, y cuando se trabaja en la gestión de recursos naturales. Es el caso del grupo de investigación del Laboratorio de Ecología de Comunidades de la UNAM. En él se desarrollan diversos proyectos de investigación con el objetivo de analizar el efecto de la explotación humana en el funcionamiento del ecosistema. Los resultados de estos estudios son tomados como base para generar, junto con los habitantes de la zona, modelos de desarrollo sustentable. El trabajo se realiza principalmente en la Reserva de la Biósfera de Tehuacán-Cuicatlán, una zona de alta diversidad biológica y cultural, pero también de alta marginación social. Aquí se presentan dos ejemplos, la ganadería extensiva y el uso de especies del genero Agave para la producción de mezcal. En ellos mostramos cómo a través de estudios científicos y de trabajo conjunto con las comunidades humanas que viven en la zona, se está consiguiendo una mejora tanto en los procesos de explotación de los recursos naturales, como en su conservación.
En este artículo presentamos los resultados derivados de un proyecto encaminado a la preparación y experimentación de un material multimedia dirigido a potenciar el aprendizaje autónomo en la ...adquisición de las competencias específicas de las prácticas de la asignatura Ecología, troncal en los estudios de la licenciatura en Biología de la Universitat de las Illes Balears (UIB). El objetivo fundamental radica en la progresiva adaptación al Espacio Europeo de Educación Superior (EEES) a partir de una mayor coordinación entre el profesorado y la obtención de nuevos recursos para la docencia. Los resultados obtenidos en la experimentación del material pueden considerarse significativamente positivos.
Common techniques currently used for reforestation in Spain consider the pre-existing vegetation (mainly shrubs) as a source of competition for trees, and consequently it is generally eliminated ...before planting. Nevertheless, it has been demonstrated that woody plants can facilitate the establishment of understory seedlings in environments that, like the Mediterranean area, are characterized by a pronounced dry season. In this study, we experimentally analyze the usefulness of shrubs as nurse plants for reforestation considering a broad gradient of environmental conditions, such as altitude, aspect, annual rainfall, nurse plant and target species. Seedlig survival was boosted under the canopy of shrubs in relation to a traditional reforestation technique, while seedling growth was not hampered. The results show therefore that the use of shrubs as nurse plants is a viable technique for reforestation in Mediterranean environments, which in addition offers both economic and ecologic advantages.
Los matorrales suelen considerarse como una fuente de competencia con los plantones sembrados, por lo que en las repoblaciones forestales que se llevan a cabo en España son generalmente eliminados antes de la siembra. Sin embargo, numerosos estudios indican que en los ambientes mediterráneos los matorrales pueden proteger a los plantones de la desecación, incrementando su supervivencia. Desde esta perspectiva, durante el período 1997-2003 llevamos a cabo repoblaciones experimentales en la provincia de Granada, considerando un amplio gradiente de condiciones ambientales, de especies repobladas y de matorrales nodriza, con objeto de evaluar la plantación bajo la copa de matorrales como una técnica alternativa de repoblación que mejore las técnicas convencionales. Los resultados obtenidos muestran que la técnica es viable, incrementando considerablemente la supervivencia de los plantones (hasta 6,2 veces respecto a las técnicas convencionales) sin reducir su crecimiento. La técnica ofrece además ventajas ecológicas y económicas respecto a las metodologías convencionales, por lo que proponemos que debe usarse extensivamente en las repoblaciones forestales realizadas en la España mediterránea.
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