Forests play a key role in the development and lives of communities worldwide. In fact, they are carbon dioxide traps and biodiversity reserves (Humphreys and Palo, 1998; Schoene and Netto, 2005). This ecological function of forests contributes to the natural balance the planet needs (CARPE, 2005). Hence, they play a major role in the water cycle by preventing loss, providing ground water and purifying water. Also, forest resources have an economic function; they provide timber, raw materials for pharmaceutical industries that use vegetable fiber and Non-Timber Forest Products. Agro-forests provide raw materials such as rubber, arabic gum, spices etc. International trade in forest products is fast growing. International trade in timber byproducts was estimated at 140 billion K in 2003 (Hashiramoto et al., 2004).Consequently, forest resources are important to the global economy. Furthermore, forests have a socio-cultural function for millions of people. They serve as a place of distraction for urban people stressed by the negative effects of modernity (FAO, 2005). Also, it is a natural stock for food, pharmacopeia and beliefs of local people who live in these natural ecosystems, especially in tropical regions (Ndoye & Chupezi, 2004). Because of these three functions, the UN Millennium Development Goals (MDG) made forest resources one of the tools in the fight against poverty and threats to the environment (Vahanen, 2006). However, interactions between these three principal functions are too complex, because they are difficult to reconcile. Most often their interests are rather conflicting, as each stakeholders desires to valorize certain functions that are of importance to them.
Despite international community awareness of the importance of natural resources, problems inherent in forests are numerous and persistent, even regarding the definition of the term. At international level, there are several definitions on what constitutes a forest (FAO, 1999). Obviously, forests ecosystems vary according to the distinctions between types of forests: tropical forest; temperate forests; boreal forests. Each one of these forest ecosystems includes several subtypes, which have special characteristics in terms of vegetation and fauna (Burley, 2002). This distinctive classification of forest blocks is at the heart of current discussions on sustainable management. Consequently, it is difficult, logically, to have uniformity in perceptions and practices, with regards to specificities inherent in the heterogeneous natural factor of forests.
For over thirty years, international law has been a tool for the protection of the environment and natural resources (Sands, 1995). Kuokkanen (2002), shows that the relationship between international law and the environment can be subdivided from the historical and substantive point of view into three successive periods: traditional, modern and postmodern. Each period has particular characteristics. This constant solicitation of international law in environmental management resulted in a kind of normative increase in the establishment of regulations for the global environment and for the preservation of natural resources (Daillier and Pellet, 2002). This recourse to international law is largely justified by the extent of the problems the worlds' environment faces. In its Advisory Opinion on the environment and as a guide for countries and other actors, the dictum of the International Court of Justice (ICJ, 1996), was: "... that the environment is not an abstraction but represents the living space, the quality of life and the very health of human beings, including generations unborn".
This analysis is made in a global context marked by the effect of various paradigms of different types, which influence forest management and international law at the same time (Dryzek, 2007). Indeed, according to Dryzek (2007), paradigms in the management of the global environment are products of natural science and social sciences as well. First of all, forests are threatened by the increase of deforestation. According to FAO estimates that 13 million hectares of forests are affected by deforestation each year (FAO, 2007). Thus, in 15 years (1990-2005), the world has lost 3 percent of its total forest cover, which represents an average loss of 0.2 percent per year. This decrease of forest cover affects the volume of carbon stored in forest biomass. In fact, a decrease of almost 5.5 percent of the world's biomass was noted between 1990 and 2005(FAO, 2007). This decrease also affects wildlife resources. The causes of the destruction of forest resources are numerous and well known (CBFP, 2006): population growth; uncertainty over ownership rights; poaching and meat bush trade; slash and burn agriculture; non-sustainable industrial logging; illegal logging; mining; climate change; construction of roads; fires; invasive plants; wars; poor governance and corruption. Secondly, the context is marked by the negative effects of climate change on the planet (Stern, 2006; IPCC, 2007). In fact, the destruction of forest resources will logically increase, especially because of disturbing and worsening phenomena like fires, plant diseases and pests. This sinister scenario is aggravated by the interconnection of between the climate, ecology, forests and biodiversity. Taking in consideration of the later evolutions/trends, our concern in this paper is mainly to analysis the construction process of an international forest law by reviewing subregional dynamics.
The literature shows that previous studies on the existence of an international forest management regime all came to the conclusion that there exists a body of rules. These rules are fragmented, incomplete and dispersed in various international conventions (Tarasofsky, 1999; Ruis, 2001; Smouts, 2008). However, an approach for the codification of these rules has been explored (Brunnee, 1996). With regards to international law, the general concept of sustainable development was first of all a declaration in the beginning, thus voluntary for all stakeholders. Second, Governments were called upon to disseminate and translate them into concrete actions. Third, the decision by the International Court of Justice (ICJ), in the Case concerning Gabcikovo--Nagymaros (ICJ, 1997), the international court highlighted the need to consider new requirements based on the concept of sustainable development when States envisage new initiatives, or when they carry on with past activities. Additionally, the Permanent Court of Arbitration (PCA, 2005), arrived at almost similar conclusions in the arbitration regarding the Iron Rhine Railway, between the Kingdom of Belgium and the Kingdom of the Netherlands. Lastly, some scholars have just asserted that the concept of sustainable development is now part of international law (Cordonier Segger, 2008; Schrijver, 2008).
Consequently, given these recent theoretical and jurisprudential developments mentioned above, it is convenient to analyze the relationship between principles of sustainable forest management and customary international law through States practice in Central America and European Union. The premise of this paper is that States practice related SFM should be considered as part of regional customary law. In this way, this article seeks to find customary law through the review of States practices on sustainable forests management in both Central America and European Union States. The first part of the paper is devoted to conceptual clarifications. The second section focuses on the study of sustainable forest management in both regions. The third section discusses the sustainable forest management States practice according the requirement of customary international/regional law.
2. Conceptual framework of the review
2.1 Concept of SFM and synthesized definitions
It is generally recognized that the concept of SFM falls within the matrix of sustainable development. This expression was used in the Brundtland Report (1987), titled "Our Common Future" submitted to the UN World Commission on Environment and Development. It suggests that future activities by the international community should focus on: "development that seeks to meet the needs and aspirations of the present without compromising the ability to meet those of the future". Consequently, States present at the 1992 United Nations conference on Environment and Development, held in Rio in, unanimously adopted the Declaration and committed to "cooperate in good faith and in a spirit of partnership in the fulfilment of the principles embodied in this Declaration and in the further development of international law in the field of sustainable development". One of the main attractions of this world forum was undeniably the issue of the management of the world's forests, given that it resulted in a Declaration of a 'Non-legally Binding Authoritative Statement of Principles'. Article 2 (b), of the Declaration states that, "Forest resources and forest lands should be sustainably managed to meet the social, economic, ecological, cultural and spiritual needs of present and future generations". Consequently, the sustainable management of forest resources is an issue of concern for the international community, States and multilateral organizations.
However, from a historical point of view, some sources date SFM practices before Rio 1992 (FAO, 2005). Indeed, it seems many countries already practiced good forest management, considering social, cultural, economic, ecological and future aspects, which are the main concern of the current concept. Hence, the similar concept of 'sustainable and balanced production' was applied for close a little over a decade, in the management of watersheds and other measures of conservation of forest lands and water (Maini, 1992). This idea of the existence of the concept before the Rio Summit is confirmed in 1983 International Tropical Timber Agreement. Though the wording in this agreement is not precise, the idea of sustainability is knitted into the expressions 'maintaining the ecological balance of the regions concerned' and 'sustained utilization and conservation of tropical forests'. To confirm this pioneering initiative aimed at forest sustainability, ITTO, the administrative organization of this international agreement, launched a study to assess the state of the sustainable management of tropical forests in its Member States. The title of the study (Poore et al., 1989), says it all--"No Timber without Trees: Sustainability in the Tropical Forest". At any rate, intentions to orientate forest management practices towards sustainability and conservation had come up before Rio. However, the concept was standardized and became clear after 1992.
The concept of SFM is of major importance in the literature. This is revealed by the plethora of studies and articles on the subject. Nevertheless, there are many definitions of the SFM. To date, there is a universally accepted definition of SFM that is not subject to criticism (Vogt et al. 2000). In this analysis, we will look at some of these definitions, drawn from …