Abstract:Montado decline has been reported since the end of the nineteenth century in southern Portugal and increased markedly during the 1980s. Consensual reports in the literature suggest that this decline is due to a number of factors, such as environmental constraints, forest diseases, inappropriate management, and socioeconomic issues. An assessment on the pattern of montado distribution was conducted to reveal how the extent of land management, environmental variables, and spatial factors contributed to montado area loss in southern Portugal from 1990 to 2006. A total of 14 independent variables, presumably related to montado loss, were grouped into three sets: environmental variables, land management variables, and spatial variables. From 1990 to 2006, approximately 90,054 ha disappeared in the montado area with an estimated annual regression rate of 0.14 % year-1. Variation partitioning showed that the land management model accounted for the highest percentage of explained variance (51.8 %), followed by spatial factors (44.6 %) and environmental factors (35.5 %). These results indicate that most variance in the large-scale distribution of recent montado loss is due to land management, either alone or in combination with environmental and spatial factors. The full GAM model showed that different livestock grazing is one of the most important variables affecting montado loss. This suggests that optimum carrying capacity should decrease to 0.18-0.60 LU ha-1 for livestock grazing in montado under current ecological conditions in southern Portugal. This study also showed that land abandonment, wildfire, and agricultural practices (to promote pastures, crops or fallow lands) were three significant variables influencing montado loss.
Multiple paternity within litters occurs in various groups of mammals exhibiting different mating systems. Using seven genetic markers (i.e., microsatellites), we investigated the paternity of littermates in free-ranging wild boar (Sus scrofa) in a Mediterranean habitat. Using the software CERVUS 2.0 we estimated the probability of detecting multiple paternity across all loci (D), the probability of paternity (W) and a statistic D that allows the assignment of paternity to the most likely male with strict and relaxed levels of confidence. Multiple paternity was inferred for one of the nine analysed litters at the 80% confidence level. This suggests that a single male may control the access to receptive adult females and it shows that multiple paternity is not very common in the studied free-ranging wild boar population. Despite the possible occurrence of sperm competition and/or female cryptic choice, mate guarding seems to play a significant role in sexual selection. To better understand the wild boar's mating strategies further studies analysing the reproductive success of both sexes and under different environmental conditions should be conducted.
Ocorreram no estudo grande número de espécies arbóreas, 79, e altos valores para os índices de diversidade e equabilidade (3,6 nats/indivíduos e 0,83, respectivamente). A distribuição diamétrica para os indivíduos que apresentaram maiores valores de cobertura e para a comunidade não resultou em padrão de J-reverso, o que indica adaptações ecológicas ao stress hídrico adotadas em diferentes estratégias de crescimento. Não houve formação de grupos florísticos, já que a alta fertilidade do solo da área de estudo configura um ambiente homogêneo. A característica da área de estudo detectada através da estrutura, associada a dados edáficos, nos permitiu vislumbrar sua importância em termos de conservação e reforçar a importância de estudos com este enfoque nas FTSS.Palavras-chave: distribuição diamétrica, Caatinga, fitossociologia, conservação.
Due to their complex structure and traditional low-intensity management, Portuguese oak woodland rangelands known as montados are often considered high nature value (HNV) farming systems, and as such, they may be deemed eligible for subsidies and incentives by governmental and nongovernmental agencies. Too little is known about how the HNV concept might be applied to conserve complex silvopastoral systems. These systems, due to their structural and functional complexity at multiple scales, tend to support high levels of biodiversity. Montados are in sharp decline as a result of the rapid specialization of land management that, through simplification, undermines multifunctionality. Understanding how changes in management influence these systems and their biodiversity is needed for prioritizing conservation efforts and for ensuring they remain HNV systems. On the basis of a field survey in 58 plots distributed among 29 paddocks on 17 farms, we conducted an integrated analysis of the relationship between grazing intensity and biodiversity in montados of similar biophysical and structural characteristics. Data on management were obtained through interviews, and biodiversity data (vegetation, macrofungi, birds, herpetofauna) were obtained through specific field protocols. Additional spatial data, such as soil characteristics, slope, land cover, and linear landscape elements, were also analyzed. The results show no overall biodiversity variation as a result of different management practices. However, different groups of species react differently to specific management practices, and within a pasture, grazing impacts are heterogenous. In low grazing intensity plots, macrofungi species richness was found to be higher, while bird species richness was lower. Using tree regeneration as proxy for montado sustainability, results show less tree regeneration in areas with higher forage quality and more intense grazing. Pathways for future progress are proposed, including creating areas within a paddock that attract grazing away from where regeneration is desired.
We examined the reproductive phenology of wild boar populations in four regions of the western Iberian Peninsula during the 1999/2000 hunting season (OctoberFebruary). To estimate conception dates and birth distribution frequencies, we used foetal weights. Regions differed significantly, and we detected a relationship between region and birth distribution frequencies. Throughout the year, food availability had a major influence on the distribution of farrowing. Although a short period of high food availability leads to highly synchronous births, even in relatively harsh environmental conditions, adult females that exploit low-quality food items appear to be able to give birth at any time of the year.
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