157 research outputs found
Windbreaks in Sustainable Agricultural Systems
Sustainable agriculture is a system of whole-farm resource use balanced with whole-farm productivity. The overall level of productivity achieved is dependent upon the ability to coordinate and manage simultaneously the soil, water, plant, and animal resources within climatic and economic limits. Both the kind and amount of plants and animals supported by the system are important and play significant roles, both individually and collectively in maintaining a healthy farm environment. In the future, integrated systems will help reduce human impact on resources while providing sufficient supplies of high quality food and fiber. Windbreaks provide protection for people, animals, buildings, crops, and natural resources. They reduce soil erosion by wind and contribute to the control of runoff from agricultural lands. Individually, trees and shrubs can provide food and shelter for wildlife or be harvested for timber and fuelwood. Specialized tree crops, such as fruits or nuts can be harvested from windbreaks providing additional economic returns
El yacimiento kárstico del Pleistoceno Superior de la Cueva del Camino en el Calvero de la Higuera (Pinilla del Valle, Madrid)
Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu
Human remains from Valdegoba Cave (Huérmeces, Burgos, Spain)
Systematic excavations, begun in 1987, at the Valdegoba cave site in
northern Spain have yielded the remains of five individuals associated
with a Middle Paleolithic stone tool technology and Pleistocene
fauna. A fragmentary mandible of an adolescent (VB1), preserving
nearly a full set of teeth, exhibits a symphyseal tubercle and slight
incurvatio mandibulae anterior on the external symphysis. Both the
superior and inferior transverse tori are present on the internal aspect.
A second individual (VB2) is represented by a set of ten deciduous
teeth consistent with an age at death of 6–9 months. A proximal
manual phalanx (VB3) displays a relatively broad head, a characteristic
which is found in both Neandertals, as well as European Middle
Pleistocene hominids. VB4 is a fourth metatarsal that lacks the distal
epiphysis, indicating it comes from an adolescent individual, and has
a relatively high robusticity index. Finally, VB5 is a fifth metatarsal of
an adult. The VB1 mandible shows a combination of archaic characteristics
as well as more specific Neandertal morphological traits. The
VB2 deciduous teeth are very small, and both the metrics and
morphology seem more consistent with a modern human classification.
The postcranial elements are undiagnostic, U-Th dating has
provided an age of >350 ka for the base of the sequence and a date of
<73·2 ± �5 ka for level 7, near the top. Faunal analysis and radiometric
dates from other nearby Mousterian sites suggests that the Valdegoba
site is correlative with oxygen isotope stages 3–6 on the Iberian
peninsula, and an Upper Pleistocene age for the Valdegoba hominids
seems most reasonable
Taphonomic Criteria for Identifying Iberian Lynx Dens in Quaternary Deposits
For decades, taphonomists have dedicated their efforts to assessing the nature of the massive leporid accumulations recovered at archaeological sites in the northwestern Mediterranean region. Their interest lying in the fact that the European rabbit constituted a critical part of human subsistence during the late Pleistocene and early Holocene. However, rabbits are also a key prey in the food webs of Mediterranean ecosystems and the base of the diet for several specialist predators, including the Iberian lynx (Lynx pardinus). For this reason, the origin of rabbit accumulations in northwestern Mediterranean sites has proved a veritable conundrum. Here, we present the zooarchaeological and taphonomic study of more than 3000 faunal and 140 coprolite remains recovered in layer IIIa of Cova del Gegant (Catalonia, Spain). Our analysis indicates that this layer served primarily as a den for the Iberian lynx. The lynxes modified and accumulated rabbit remains and also died at the site creating an accumulation dominated by the two taxa. However, other agents and processes, including human, intervened in the final configuration of the assemblage. Our study contributes to characterizing the Iberian lynx fossil accumulation differentiating between the faunal assemblages accumulated by lynxes and hominins
First Early Hominin from Central Africa (Ishango, Democratic Republic of Congo)
Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma), and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine) branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25) from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ) surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma
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