121 resultados para Land Use Diversity
Resumo:
The sudden independence of Kyrgyzstan from the Soviet Union in 1991 led to a total rupture of industrial and agricultural production. Based on empirical data, this study seeks to identify key land use transformation processes since the late 1980s, their impact on people's livelihoods and the implication for natural resources in the communes of Tosh Bulak and Saz, located in the Sokuluk River Basin on the northern slope of the Kyrgyz Range. Using the concept of the sustainable livelihood approach as an analytical framework, three different livelihood strategies were identified: (1) An accumulation strategy applied by wealthy households where renting and/or buying of land is a key element; they are the only household category capable of venturing into rain fed agriculture. (2) A preserving strategy involving mainly intermediate households who are not able to buy or rent additional agricultural land; very often they are forced to return their land to the commune or sell it to wealthier households. (3) A coping strategy including mainly poor households consisting of elderly pensioners or headed by single mothers; due to their limited labour and economic power, agricultural production is very low and hardly covers subsistence needs; pensions and social allowances form the backbone of these livelihoods. Ecological assessments have shown that the forage productivity of remote high mountain pastures has increased from 5 to 22 per cent since 1978. At the same time forage productivity on pre-mountain and mountain pastures close to villages has generally decreased from 1 to 34 per cent. It seems that the main avenues for livelihoods to increase their wealth are to be found in the agricultural sector by controlling more and mainly irrigated land as well as by increasing livestock. The losers in this process are thus those households unable to keep or exploit their arable land or to benefit from new agricultural land. Ensuring access to land for the poor is therefore imperative in order to combat rural poverty and socio-economic disparities in rural Kyrgyzstan.
Resumo:
Forests near the Mediterranean coast have been shaped by millennia of human disturbance. Consequently, ecological studies relying on modern observations or historical records may have difficulty assessing natural vegetation dynamics under current and future climate. We combined a sedimentary pollen record from Lago di Massacciucoli, Tuscany, Italy with simulations from the LandClim dynamic vegetation model to determine what vegetation preceded intense human disturbance, how past changes in vegetation relate to fire and browsing, and the potential of an extinct vegetation type under present climate. We simulated vegetation dynamics near Lago di Massaciucoli for the last 7,000 years using a local chironomid-inferred temperature reconstruction with combinations of three fire regimes (small infrequent, large infrequent, small frequent) and three browsing intensities (no browsing, light browsing, and moderate browsing), and compared model output to pollen data. Simulations with low disturbance support pollen-inferred evidence for a mixed forest dominated by Quercus ilex (a Mediterranean species) and Abies alba (a montane species). Whereas pollen data record the collapse of A. alba after 6000 cal yr bp, simulated populations expanded with declining summer temperatures during the late Holocene. Simulations with increased fire and browsing are consistent with evidence for expansion by deciduous species after A. alba collapsed. According to our combined paleo-environmental and modeling evidence, mixed Q. ilex and A. alba forests remain possible with current climate and limited disturbance, and provide a viable management objective for ecosystems near the Mediterranean coast and in regions that are expected to experience a mediterranean-type climate in the future.
Resumo:
There is increasing evidence that species can evolve rapidly in response to environmental change. However, although land use is one of the key drivers of current environmental change, studies of its evolutionary consequences are still fairly scarce, in particular studies that examine land-use effects across large numbers of populations, and discriminate between different aspects of land use. Here, we investigated genetic differentiation in relation to land use in the annual grass Bromus hordeaceus. A common garden study with offspring from 51 populations from three regions and a broad range of land-use types and intensities showed that there was indeed systematic population differentiation of ecologically important plant traits in relation to land use, in particular due to increasing mowing and grazing intensities. We also found strong land-use-related genetic differentiation in plant phenology, where the onset of flowering consistently shifted away from the typical time of management. In addition, increased grazing intensity significantly increased the genetic variability within populations. Our study suggests that land use can cause considerable genetic differentiation among plant populations, and that the timing of land use may select for phenological escape strategies, particularly in monocarpic plant species.