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In implantation trials carried out with Prosopis chilensis and Prosopis flexuosa, the following variables were considered: implantation time (December and March), implantation technique (direct seeding and seedling transplantation) and age of the seedlings at the time of transplantation (60, 105 and 150 days). Survival was evaluated for more than 9 months after implantation and trials were repeated in 3 consecutive years.

Results from both species were similar and they show that survival after transplantation was higher (60–80%) than from direct seeding (35–45%). Survival from transplantation was independent of the size and age of the seedlings and it was less affected by climatic conditions than direct field sowing. Survival from direct seeding was higher in March than in December. The best time for either implantation alternative would be the end of the summer or beginning of fall, when climatic conditions increase the probability of seedling survival.  相似文献   

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Little is known about the potentially disrupting effects of wind farms on the habitat connectivity of flying vertebrates at the landscape scale. We developed a regional-scale model to assess the wind farm impact on bat migration and commuting routes. The model was implemented for the bat Nyctalus leisleri in a region of central Italy currently undergoing considerable wind farm development. A Species Distribution Model (SDM) for N. leisleri was generated using the MaxEnt algorithm based on 47 presence records (reduced to 19 after the autocorrelation procedure) and 10 environmental variables derived from topographic and land cover maps. We used the SDM to create a map of connectivity using the software UNICOR to identify potential commuting corridors (PCCs). The incidence of each wind farm on bat flight corridors was assessed by overlaying the existing (380) and planned (195) turbine locations onto the PCCs. The SDM was statistically robust (AUC > 0.8). Most of the corridors were concentrated in the western part of the region, which hosts the largest suitable areas for the species; most of the existing (54 %) and planned (72 %) wind farms interfered with important corridors connecting the western and the eastern parts of the region. Our results provide key information on the impact of the wind farm industry on biodiversity on a regional scale. The novel approach adopted, based on SDM and connectivity analysis, could be easily extended to other flying vertebrates and landscapes and constitutes a promising planning tool necessary for harmonizing the development of renewable energy infrastructures with issues of biodiversity conservation.  相似文献   
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Reproductive phenology is an important trait subjected to natural selection. Current horses in America belong to the Palearctic original populations after being introduced by European colonizers. Photoperiod variation is the main environmental factor for the adjustment of reproductive timing in horses, but is absent in equatorial areas. Here we hypothesize that seasonality of green‐grass availability may influence breeding phenology in equatorial regions. We used data of 929 services to mares from 2006 to 2011 in a thoroughbred equine exploitation in Ecuador that experienced strong grass seasonality. Actual births could not be used to infer natural phenology because they were influenced by management decisions. Instead, we used variations in the probability of pregnancy after a service as a measure of the natural tendency of mares to show breeding phenology. We found that although managers tended to schedule pregnancies in two periods within the year, mares were more prone to become pregnant after the increase in grass greenness that takes place at the beginning of the year (February). Our finding has potential applications to improve the success of services and the welfare of animals, by providing green‐grass stimuli in the appropriate season.  相似文献   
6.
Intensification of game management may increase the prevalence of tuberculosis (TB) in wildlife despite eradication programs implemented in cattle herds in the same areas. In this cross-sectional study, we investigated the association between wild game management practices and the presence of tuberculosis in red deer populations in Southwestern Spain. Five hundred and fifty-one animals were examined by necropsy to detect tuberculosis-like lesions in the main lymph nodes. Prevalence, as determined by TB-like lesions, was estimated to be 5.1% of animals, with 77% of TB-like lesions confirmed by PCR. Our results suggest that population density, in addition to factors which promote the local aggregation of animals, is factors associated with increased prevalence of TB in red deer populations. We suggest that management practices including supplementary feeding, fencing, water ponds and interaction with domestic livestock should be revised in order to prevent TB in wild deer both.  相似文献   
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Modeling habitat connectivity for conservation of semi-aquatic vertebrates is a particularly challenging task, due to the fine-scale and linear distribution of riverine habitats and to the capacity of species to move both on freshwater and terrestrial realms. We showed how the integrated analytical framework provided by the habitat availability (reachability) metrics and their fractions can be used to effectively evaluate the distinctive roles and contributions of both habitat patches (aquatic and riparian) and linkage areas (permeable land matrix) to the connectivity and functioning of a complex system composed of multiple river catchments. Analysis focused on the Eurasian otter (Lutra lutra L.), one of the most endangered mammals in Italy. We developed a network connectivity model based on suitable otter habitats and multiple least-cost paths between catchments. A graph analytical approach was used to identify critical nodes and links for the potential expansion and long-term viability of the species in the region. Our results showed that few basins concentrate most of the importance for sustaining the overall habitat connectivity, due to the extension of suitable habitats they contain, their strong connections with other basins, and their importance as stepping stones that uphold ecological fluxes between otherwise weakly connected habitats. The potential contribution of each basin to enhance the dispersal and expansion of otters in the area strongly depended on the key functional paths (sequences of links and nodes) among the catchments. We identified vacant basins that could be colonized by otters in the near future, and connecting areas in the intermediate matrix that might be preferentially used to conduct and promote dispersal movements and gene flow in the area. The novel approach here adopted could be easily extended to other semiaquatic species and catchment systems, offering a management strategy to preserve the hydrographic network as an integrated system, as well as a joint evaluation of the role of both the river courses and the matrix in between in a single landscape model.  相似文献   
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Pelagic longlines are widely known to interact with several species of sea turtles, and there is an increasing concern about the by-catch of turtles in commercial fisheries and its impact on their populations. However, information on sea turtle by-catch in the South Atlantic Ocean is scarce, and there are no quantitative by-catch data available on olive ridleys for the Equatorial Eastern Atlantic. In this paper we analyze data collected by observers on board an Uruguayan long-liner targeting swordfish in two areas in the Equatorial Eastern Atlantic: off the Gulf of Guinea and north of Saint Helenaa Island. Specimens of Lepidochelys olivacea and Dermochelys coriacea were hooked or entangled in 26 longline sets. All registered interactions with olive ridleys took place off the The Gulf of Guinea, with captures ranging from 1 to 3 specimens in a single set. The captured specimens, though not measured directly, appeared to be juveniles. In addition, the examination of the stomach contents of one female mako shark showed dermal scutes, vertebrae and the complete head of a sea turtle identified as L. olivacea, allowing us to estimate its curved carapace length. In contrast, adult specimens of D. coriacea were caught in the two fishing areas. The capture of 10 individuals in a single set was recorded. Due to the high rate of sea turtle by-catch observed off the The Gulf of Guinea (1.02 ind/1000 hooks) conservation programs in the area should take into consideration the possible existence of a developmental and feeding area in this zone. Accordingly, longline fisheries in this area should be monitored and mitigation measures put in place to avoid or minimize damage to the pelagic phase of African populations of sea turtles.  相似文献   
9.
Using indirect immunoperoxidase (IIP), peroxidase anti-peroxidase (PAP) and avidin biotin-peroxidase complex (ABC) immunohistochemical methods, Mycoplasma gallinarum and M gallinaceum antigens were demonstrated in ethanol-fixed paraffin-embedded oviduct sections from hens the eggs from which showed suboptimal hatchability. Specific immunoperoxidase staining was detected at the mucosa in the magnum portion of the oviduct. Optimal staining was achieved by applying the ABC method, though both IIP and PAP methods can also be used for diagnosis. Isolation and identification techniques gave similar results for the species of avian mycoplasmas involved.  相似文献   
10.
Horse reproduction tends to be seasonal. The main adjusting factor in their original temperate ranges is photoperiod variation, although it is absent in equatorial areas where horses were introduced by European colonizers. Hence, dates of reproduction in these areas may be influenced by factors affecting mares’ conditions and the success of foaling. Here we study reproductive timing in Creole horses in Ecuador reared in an extensive production system. We found that foaling peaked in August. Mares’ conditions showed one peak in June‐July, before the start of the breeding season, and another in December, and it was highly variable along the year. Mares’ conditions increased after a period of vegetation growth and thus appeared negatively associated with the increment of grass greenness (normalized difference vegetation index data). Seasonal flooding of some pasturelands during March and April appeared to seriously impair mares’ conditions and probably influenced the timing of foaling toward the dry season. Our results evidenced that horse breeding in these equatorial areas tended to be seasonal and point to some key factors that influence phenology by affecting body condition of mares, which may have implications for horse biology and management.  相似文献   
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