**1. Introduction**

The first Portuguese Landscape Architect, Francisco Caldeira Cabral, reflected on how nature conservation should not be seen from a museology perspective, where Man is external to the object of protection. He defended that every person is an integral part of nature conservation by actively participating in protecting natural resources and constructing the landscape.

*(…) a campaign of general mentalization began for the need as a condition of urban and rural life, to maintain in congruent form the essential elements of the*  *natural landscape, conserving or even reconstituting its continuity and functionality. Thus became aware of maintaining the " continuum natural " and the " continuum cultural [1].*

Since our existence, humankind has established interactive and empirical relationships with the Landscape [2], searching for defensive systems at higher elevations and safeguarding the fertile valleys as food producers essential for survival. But the interaction between Man and the ecosystems is bidirectional, where an action of Man on a particular ecosystem will imply a reaction and an adaptation of the ecosystem [3].

Landscape and land-use planning are intended to plan human interventions that maintain or promote the landscape's dynamic stability. The stability of the landscape is associated with slow landscape evolutions (pedogenesis), while instability is characterized by rapid changes (morphogenesis) [4]. The balance between morphogenetic and pedogenetic processes is a natural process of the landscape, which can be intensified towards instability by an incorrect action in the territory. The planning of human intervention in the territory in harmony with ecological systems has resulted in preserving natural resources and nature conservation.

The understanding of the functioning of natural systems, or ecosystems, as a support for decision making [5] emerged after the foundation of ecology as a science, in the mid-nineteenth century, by Ernest Haeckel. The evolution of knowledge about the ecological processes in a given territory allowed the development of ecology-based landscape planning methodologies.

Following the Convention on Biological Diversity [6], one of the decisions taken at the fifth Conference of the Parties to the Convention on Biological Diversity [7] was that biodiversity conservation objectives could only be achieved through an ecological-based approach:

*(…) a strategy for the integrated management of land, water, and living resources that promotes conservation and sustainable use in an equitable way. It is based on the application of appropriate scientific methodologies focused on levels of biological organization that encompasses the processes, functions and interactions among organisms and their environment. It recognizes that humans, with their cultural diversity, are an integral part of ecosystems [7].*

Ecological-based methodologies start from the knowledge and spatialization of natural processes that occur in a given territory [8]. With this approach, the most significant areas for ecosystem functioning are identified in the landscape, with various potentialities, and actions are planned without compromising the stability and balance of the landscape. This approach is related to the concept of ecological suitability to the various human activities that do not compromise the proper functioning of ecological processes [9].

The concept of ecological suitability was used in the United States of America and the United Kingdom, using the manual overlay of transparent supports, whose methodologies were refined throughout the 1960s [10]. Other landscape architects followed, such as the work done by Philip Lewis, in 1964, to classify all the environmental resources of the State of Wisconsin, with the purpose of delimiting the areas where building should not be done [11]. The concept of ecological suitability was also considered in McHarg's [12] and Steiner [13] methodologies with the study of environmental processes and cultural integration in the choice of the best use, according to the intrinsic characteristics of the systems. In Portugal, contemporary

*Contributing to Healthy Landscapes by Sustainable Land Use Planning: A Vision for Restoring... DOI: http://dx.doi.org/10.5772/intechopen.99666*

with McHarg's methodology, the Algarve Plan was completed by landscape architects A. Barreto, A. Castelo-Branco and A. Dentinho, with methodologies based on ecological suitability of the Landscape [11].

The adequate planning of the landscape, according to the ecological processes that occur in it, impacts not only the ecological balance but also on the economic and social balance. This type of intervention has the ability, in a cost–benefit analysis, to be the best way to prevent future costs arising from natural disasters (flood prevention, fire risk reduction, mass movement), maintain water quality, ensure greater agricultural productivity, and contribute to the enhancement of urban areas [14]. Of this last point, the study done [15] in the case study of Cologne (Germany) concluded that increasing urban parks by 1%, about 500 meters from housing, leads to the growth of housing sales prices by 0.1%. With a priori protection of natural resources, engineering solutions are less, and the cost is lower [14].

The economic valuation of ecosystems was developed with the emergence of the ecosystem services concept [16] and spread at the beginning of the 21st century with the publications of the Millennium Ecosystem Assessment. Different local scientific and political communities started raising awareness of the importance and benefits of ecosystem services. Several initiatives and methodologies have emerged to quantify these services in monetary value. However, there are sometimes limitations in quantifying an ecosystem service [17].

Ecological-based planning has the added advantage of helping to increase the number or quality of services provided by ecosystems. Inherent in the concept of ecological-based planning is the continuity and ecological network [18]. In fact, landscape connectivity is a component of landscape structure that facilitates or impedes the flows of natural cycles [19]. Those authors believe that it is more critical to establish connectivity than the proximity of areas studied in "island biogeography" [20].

Like nature conservation, the ecological continuity of ecosystems is a broad concept that involves the need to promote continuity between plant and animal species and that of all ecological cycles: water, nutrients, carbon, etc. For this, the planning of these continuities (ecological structures or networks) cannot be disconnected from the function and its "congruent form", as defined by the landscape architect Francisco Caldeira Cabral [1]. The land-use planning approach advocated, plans the landscape from a biophysical and not only biological perspective [11, 21], where the continuous structures of the landscape are identified and planned according to their function and coherent form.

The importance of connecting nature protection areas, establishing a network or infrastructure has been reinforced [22]. According to this publication, this type of infrastructure, designated by green infrastructure, can mitigate fragmentation and promote the various benefits of maintaining and restoring ecosystems and their services, not only inside Natura 2000 areas.

However, as mentioned above, nature conservation should be understood as a comprehensive and integrative concept of Man and ecological processes, not limited to classified areas (RAMSAR Areas, Biogenetic Reserves, Natura 2000 Network, etc.). Nature conservation will emerge from the correct occupation and use of the Landscape by Man, both in terms of building, forest, woodland and/or agriculture. Therefore, the incorporation of ecological processes in the nature conservation strategy is necessary [23], not forgetting that: (1) ecosystems are spatially and temporally dynamic; (2) ecosystem components interact with each other contributing to biodiversity; (3) ecological processes act as species-selective forces; (4) in highly modified sites ecosystem restoration is a conservation priority.
