Puya alata

Although the Bolivian Chaco has remained more intact than its Argentinean counterpart, much of the region is in various stages of alteration and degradation and this process is at present accelerating. The original landscape of the region was mostly a parkland with patches of hardwoods intermingled with grasslands. This mosaic of original vegetation was kept stable by periodic fires caused by lighting or by indigenous people. Reduction in fire intensity and frequency due to introduction of grazing and withdrawal of Indians led to the invasion of woody vegetation into the grasslands. The large herbivore fauna of the Chaco became extinct in the Pleistocene, allowing the evolution of grass and herb species not adapted to grazing. Increasing human encroachment, largely by poor campesinos with associated overgrazing (cattle and goats), excessive timber harvesting, charcoal production and over exploitation of wildlife have altered ecological processes and have an increasing and dramatic negative impact on the biodiversity and potential productivity of the natural vegetation, gradually transforming the region into a dense and unproductive shrubland dominated by woody weeds (Bucher and Huszar 1999). The Bolivian Chaco has remained largely unoccupied, although expansion of campesinos into previously inhabited areas continues, favoured by the recent opening of the Trans-Chaco highway between Bolivia and Paraguay. Expansion of soybean plantations following a decade of unusually high rainfall and large scale ranching projects, that introduces single species pasture and eliminates all native vegetation, are other threats to plant species in the region (Bucher and Huszar 1999). The taxon was collected in an area where human population density and human footprint have remained very low (GIS data, Sanderson et al. 2002). Its resilience to disturbance, especially grazing, and its regeneration abilities are unknown. The plant has only been described from fragments and its biology and ecology have not been studied.

Because of its low population and little economic significance, the Bolivian Chaco receives little economic and political support. The area where the species was collected does not benefit from any protection and more protected areas are needed in order to save this habitat from overwhelming agricultural development. In the Chaco of the Province of Salta, Argentina, a management system, based on the restoration and sustainable use of public and private land through a multi-species ranching system is proving to be able to protect and enhance the resource base while providing higher economic returns in a sustainable manner. Although high initial costs as well as divergence between the best interests of campesinos and society jeopardize the feasibility of the Salta management system, it provides a unique opportunity for planning development in areas of Bolivian Chaco which are currently unoccupied. The area has been very neglected in terms of biological inventories, and it is not known whether the taxon still occurs in the region or has gone extinct (Bucher and Huszar 1999). The locality and surrounding area should be surveyed as well as the soil seed bank in the area. If the taxon still occurs, its range and population should be estimated and closely monitored. Its resilience to disturbance, especially grazing, as well as regeneration capacities should be investigated. Seeds should be collected for germplasm conservation. If seeds of the taxon are available, these should be grown ex situ towards a potential reintroduction in intact or restored habitats. It has previously been listed as Endangered on the 1997 Red List.