1.2 Hominid frontier expansion and cultural landscape
Land cropping and the following appearance of the rural cultural open landscape[9], occurs only starting around 10.000 years ago. This is the starting point of the process of landscape hominization [45, 46] and the homind frontier expansion. Each society relates differently to nature and its surroundings, arranging the territory according to its culture, setting the bases of the different cultural landscapes.
The nature artificialization process, and the expansion of the hominid frontier is intended to conquer niches and improve anthropogenic canalization of goods and services, requiring the extraction and insertion of elements into the ecosystem.
As example of the hominid frontier expansion and creation of a cultural landscape, Gasto [47] reports what happened in the range lands of the North American west. After the arrival of settlers there was degradation of the soil and vegetable covering, and as a consequence of this, large stretches of land were abandoned due to low productivity. These settlers didn’t have the necessary knowledge to open up, order, manage and administer the territory. Faced with this, the Government, got involved and establishes the National Park Service (1873), National Forest (1890), Native American Reservations, Wild Life Shelters and the Land Grant College. At the same time, and in order to improve the public land management, the Government set up the Forest Service (1905), Bureau of Land management-BOM (1935), and the Soil Conservation Service (1905). Meanwhile settlers were converting private land into great ranches. The American Society of Range Land Management was created in the 1940’s, with the intention of developing a science based on principles differing from those of agronomy. Currently one of the most important aspects is
the publishing journal of range management for continuous renewal of concepts, technology, and guidelines, in order to be consistent with the demands of society and maintain the sustainability of the territory [28]. Because this, "rangeland" is an expression of the contemporary American cultural landscape.
Another interesting case of cultural landscape generation is dehesa[10], in Mediterranean Spain. Dehesa corresponds to a cultural landscape created and developed by the popular culture. By definition it is a typical natural dense sclerophyllous Mediterranean forest, with a simplified structure and diversity of species achieved by reducing the tree density by pruning and thinning, developing isolated fruit producing trees loaded with acorns and stimulating the formation of a natural prairie in the undergrowth [47, 48]. Two main livestock niches are generated: one of the acorn consuming pig and the other of the ruminant ovine and bovine grass consumers (Gasto 2008). The evolution of the dehesa, of its elements and landscapes is deeply related to the development of the transhumant livestock, which has been very important for the Iberian development. According to Gasto [47] the dehesa is a sustainable system by generating products of great value while maintaining landscapes of immense aesthetic value with a mixed wintry herbaceous cover and evergreen trees.
In both cases, the rangeland in the United States, as well as, the dehesa in the Iberian peninsula, the expansion of the hominid frontier and of the construction of the cultural landscape, created a stable cultural landscape, harmonizing the economic, social and ecological services with a remarkable identity [49].
Easter Island on the other hand has become an emblematic case [12, 50] of a very fast hominid frontier expansion, which extremely modified and depleted a fragile ecosystem (isolated area in the middle of the Pacific, 388 Km2). There are various hypotheses, which explain this particular degradation process. Some of them suggest that the deforestation and severe depletion of the ecosystem was the result of the increased demand for logs used for the transportation of the Moais, and that the population of the Island got to be 7.000 [12]; other hypothesis sustain that the disease and slavery brought by the Europeans were the main reason that triggered the population crisis, aside from the introduction of the Polynesian rat that prevented the forest from regenerating and generalized harvest [50]. Nevertheless, the Eastern Island society colonized said territory but failed in its attempt to make it sustainable, producing the depletion of its own ecological support and thus, its own extermination.
In each one of these situations (rangeland, dehesa and Easter Island) man colonized a territory, expanded the hominid frontier, artificialized nature and transformed the ecosystem, creating a new cultural landscape to fit their needs, culture and technology, and attaining an improved or poorer system in terms of sustainability and life quality [28, 49].
