Introduction A State, in spite of its territorial supremacy
State Sovereignty today is the core principle behind interstate relations and our modern day world order. The concept of State Sovereignty contributed largely to the architecture of our present day nation-state system, and is embodied today through political authority. State Sovereignty as understood today can be traced back to the Treaties of Westphalia in 1648. However, it was not until the end of World War II that there was a worldwide move towards a system of sovereign states. Consequently, much of International Law after the Second World War was designed to reinforce the concept of Sovereignty.
Until the middle of the 20th century, states assumed ‘full’ and ‘absolute’ sovereignty and used the resources within their territories regardless of the impact it might have on neighbouring States. Today, territorial sovereignty is not understood as an unlimited concept enabling a State to do whatever it likes. This is because activities of one State often bear upon those of others and, consequently, upon their sovereign rights. For this reason, the legitimacy of the concept of State Sovereignty today is questioned. Indeed for many jurists such as Professor John Jackson, State Sovereignty is an outdated concept  that does not fit into the global world of today.
Environmental degradation is a rising concern for the world, but domestic laws and political aims such as economic development often have the priority. Never before had the concept of State Sovereignty been so disputed until the world faced the reality of how far nations are ecologically interdependent. Indeed, the biological, chemical, and ecological systems of the Earth operate without paying heed to the artificial distinctions between nations  . Although on the international level the concept of state sovereignty seems to be eroding, the reality remains that we do not have today an alternative  to the sovereign states system.
In the absence of real universal cooperation where nature conservation would be one of the world’s priorities, the question that needs to be answered is: How to reconcile the concept of State Sovereignty with its implication of non-interference, with the rising environmental threats human activities are causing to our plant and animals species?
Chapter 1- State Sovereignty
State Sovereignty although disputed is undeniably the foundation concept of International Law. In order to fully understand how our nation-state world system attempts to protect nature, we need to understand the workings of the concept of state sovereignty. This chapter is consequently devoted to the modern implications of this concept.
1.1 Westphalian Sovereignty
The word Sovereignty  is of Anglo-French origin and can be dated back to as early as the 14th century. Sovereignty is defined as the quality of having supreme ruling authority over an independent territory. This authority is possessed by the governing individual or institution of that territory, which is the Sovereign. One of the most notable definitions of this authority possessed by the Sovereign is that proposed by American philosopher Robert Paul Wolff: “the right to command and correlatively the right to be obeyed." 
As a concept, the meaning of Sovereignty has varied other time and to be fully understood it cannot be isolated from history. During the middle of the 14th century, sovereignty was mainly an internal concept meaning “ruling authority." It was considered a de jure right of the royalty or nobility. Europe at that time was very far from the idea of a state with many political philosophers such as French jurist Jean Bodin  thinking that sovereignty must reside in the hands of only one individual.
The concept of “State Sovereignty" in the modern sense "existence as an independent territory" only appeared during the 17th century  . It was the 1648 agreements concluded by European states as part of the Treaties of Westphalia  that laid the present foundations of International Law with regard to State sovereignty. The agreement at Westphalia was the first modern diplomatic congress and it marked the beginning of a new political order in Europe.
This so called Westphalian Sovereignty was centred on the concept of the nation. It advocated the equality of states, territorial integrity and border inviolability which will be discussed in details later on. State sovereignty was defined by Wang  as conferring onto states a three-fold capacity, which is the “absolute supremacy over internal affairs within its territory, absolute right to govern its people, and freedom from any external interference in the above matters." Westphalian sovereignty in one word gave states autonomy  .
In this Westphalian system, states were the primary subjects of International Law and had both internal and external control. The sovereign states system that was advocated at Westphalia slowly implemented itself in Europe. With European colonisation, this system spread worldwide over three centuries. After the decline of the European colonial empires in the mid-20th century, the state became the only form of polity ever to cover the entire world.
Today the concept of State Sovereignty lies at the heart of both customary international law and the United Nation Charter. Indeed, norms of sovereignty as expressed in the treaties of Westphalia are enshrined in the Charter of the United Nations in its Article 2(1)  . For decades, this concept has provided states with an identity and has created a system more or less characterized by order and stability.
1.2 State Sovereignty as Absoluteness
Modern Public International Law views State Sovereignty as denoting the competence, independence, and legal equality of states. The concept refers to the legal capacity of a state under International Law to decide and act upon matters within its territory without foreign intrusion. State Sovereignty was famously described by Max Huber, Arbitrator in the Island of Palmas Arbitration  case, in the terms:
“Sovereignty in the relation between States signifies independence. Independence in regard to a portion of the globe is the right to exercise therein, to the exclusion of any other State, the functions of a State."
This independence relates to political, economic, environmental, social, and cultural matters as well as the formulation of foreign policy. This control that is inherent to State Sovereignty has often caused the concept to be associated to absoluteness. Firstly this is because, once power is given to the ruling authority, it becomes the source of all laws. Secondly this is because in the present organization of our world system state sovereignty is the contrary to intervention.
This absoluteness is however debatable. Indeed, scholars have for long advocated that State Sovereignty is a social contract  and that it is constrained and regulated by the constitutional system of each state. In this system, the governing authority is given power by the community. This theory of the social contract is the root of our modern concept of popular sovereignty. Indeed, in democracies today political powers are giving to governments by the community through votes.
Even though governing authorities are given power through the will of citizens, we are still confronted with a question: how is this governing authority voicing out the will of the citizens? This question has often no substantial answer and leads to the conclusion that internally Sovereign authority is absolute. This does not mean however that there is no accountability in a Sovereign State. In his article on Sovereignty Dan Philpott  proposes the view that sovereignty is supreme but not absolute. Therefore, while the governing authority is the source of law and at the head of the state’s administration, its authority is not absolute because it is accountable to its people.
Externally, State Sovereignty can further be seen as absolute because it is the opposite of intervention in the affairs that are within the domestic jurisdiction of states. Non-intervention is the very foundation of state sovereignty. As Oppenheim  said, the prohibition of intervention “is a corollary of every state’s right to sovereignty, territorial integrity and political independence." These principles of non-intervention and territorial integrity are analysed below.
Territory Integrity and Non- intervention
Territorial Integrity refers to the respect of a state’s borders. This principle of international law works by condemning acts of aggression by other states and placing limits on migration. The principle goes further than just prohibiting external aggressions. It also condemns border changes or secessionist movements  . Explaining the importance of this principle, in its 1949 report  the International Court of Justice observed:
"…between independent States, respect for territorial sovereignty is an essential foundation of international relations."
Territoriality is taken for granted today, but for centuries, armed conflicts and conquests meant that territories kept changing hands. During the middle Ages, territorial borders were not fixed. This lack of territorial integrity has been analysed as the reason why rulers, kings and emperors did not possess absolute sovereignty  . Even after the Treaties of Westphalia, conquests and intervention for matters relating to religion for example were common. In his article, Mark Zacher argues that states did not gain full territorial integrity until the 20th century.  Indeed, it was as late as in 1919 that the redistribution of Europe was concluded at the Versailles Peace Conference.
Without a territory, a state cannot exist on the international level. Indeed, the Montevideo Convention on the rights and duties of States of 1933 provides in its Article 1  that a state should possess four qualities: A permanent population, a defined territory, a government and lastly, capacity to enter into relations with other countries. These conditions are not absolute. For example, referring to a defined territory, the German-Polish mix Tribunal explained in the case of Deutsche Continental Gas- Gesellschaf v Polish State  :
“In order to say that a State exists and can be recognised as such it is enough that its territory has a sufficient consistency even though its boundaries have not yet been accurately delimited."
Once a State fulfils the four conditions set out in Article 1 of the Montevideo Convention, its borders become inviolable. Even if other countries refuse to recognise the state  , its borders are still inviolable as explicitly stated in Article 3 of the Montevideo Convention of 1933  . This is the main danger behind the concept of State Sovereignty. Indeed, under International Law, no other state may investigate, or intervene in its affairs. This has led to various abuses of power by governments other the year.
State Sovereignty as mentioned above, is the opposite of intervention. Therefore, to fuller understand state sovereignty, intervention must also be understood. in 1922, P.H. Winfield  referred to Intervention as being a vague concept under International Law. Indeed, he explained that there is no certainty whether intervention is a right or an exception. The recent intervention in Iraq in 2003 was followed by such a big debate that it is clear that intervention is still vague today.
According to the rules of International Law, it seems that intervention is the exception. Indeed non-intervention is applicable to the United Nations as provided for in Chapter VII of the UN Charter while non-intervention by states has been propounded in Article 2(4)  of the UN Charter. Intervention is the exception and has a specific aim that is to “maintain or restore international peace and security  ". Other conventions and agreements have also made provisions for intervention to protect citizens against abuses perpetrated by other states. For example the GATT Agreement provides for trade remedies, investigations and other state interventions in cases of dumping  .
These provisions under International Law have led to three broad instances of intervention throughout history; firstly, intervention in cases of human rights violations  , secondly intervention for economic reasons and lastly diplomatic interventions. A new form of intervention that is being studied is environmental intervention  . States had no real interest in protecting the environment for a long time and therefore no country intervened even if other states were damaging the environment. The relevance and importance of intervention as an exception to state sovereignty when it comes to nature conservation will be analysed in chapter 2.
International Law within the domestic sphere
International Law governs the commitment of states to respect the treaties they sign voluntarily. However, international law does not set a specific way in which countries are to incorporate the treaties they sign into their internal legal systems. The concept of state sovereignty implies that it is left to the state to decide how to incorporate these conventions into their domestic spheres. This once again can lead to the conclusion that state sovereignty confers onto states absolute power.
Different states have different practices as to the operation of international law within the domestic sphere. There are two principle theories of incorporation known as monism and dualism. According to monist writers such as Kelsen  , international law and national law are two components of one system. This unity means that once a convention is signed, it becomes enforceable at the domestic level.
It is interesting to note that state practice is different even among countries that adopt a monist approach. For example, in Germany the Section 25 of the Constitution states that international conventions become domestic laws as long as they don’t conflict with the Constitution itself. In the United States also, according to the Section 2 of the Constitution, the supreme law is again the Constitution itself. In the Netherlands on the other hand municipal laws are invalid if they conflict with international law.
Contrary to the monist theory, dualism denies that international law and national law operate in the same sphere, although it does accept that they deal with the same subject matter. This dualist view stems from the concept of state sovereignty itself with authors such as Hegel emphasizing on the will of the State. Since the dualist theory makes a distinction between international law and domestic law, incorporation is necessary to apply international conventions to the domestic level. This is the case for England and most of the common wealth countries such as Mauritius. Incorporation means that international conventions must be transformed into an Act of Parliament before they can have any force of law.
Despite the fact that there are many different state practices for the incorporation of international conventions, it can be argued that no system overcomes the obstacle posed by the concept of state sovereignty. Indeed, the ratification of international conventions remains voluntary in accordance with the principle of state sovereignty. Even after ratification, compliance is again voluntary. Therefore, there is no way of forcing countries to adopt or comply with international conventions. It has been however argued countless times that international pressure and sanctions  play a positive role in the enforcement of international conventions.
1.3 Emerging World Challenges and State Sovereignty
For a long time, state sovereignty has been a sanctuary, where states could act without interference from other states. Today, because of the world challenges that we are facing, whether they be political, economic or environmental, it is clear that no state will benefit by isolating itself. While state sovereignty has created a stable world system and has been very important in the past for the development of our modern world, there is a need to make it weaker. Indeed, the present notion of state sovereignty makes it difficult to tackle international threats such as disarmament, environmental degradation and economic crises.
State Sovereignty and Globalisation
At its core, globalisation means the increasing flow of goods, people and ideas across borders. Globalisation therefore challenges one of sovereignty’s fundamental principles: the ability to control what crosses borders in either direction. It is true to say that sovereign states increasingly measure their vulnerability not to one another, but to forces beyond their control. Does globalisation thus imply that sovereignty is becoming weaker in reality?
According to Steven D. Krasner  , there is a decline in the autonomy of states. However he argues that “Those who proclaim the death of sovereignty misread the history. The nation state has a keen instinct for survival and has so far adapted to new challenges, even the challenge of globalization." State sovereignty is not likely to disappear any time soon but it needs to become weaker.
The first reason today why state sovereignty needs to become weaker is that the world’s 190-plus states now co-exist with a larger number of powerful non-sovereign actors such as non-government organisations (NGOs), terrorist groups, drug cartels, regional and global institutions and powerful corporations. Therefore, we need new mechanisms of global governance that include actors other than states. The second reason why state sovereignty needs to be weakened is that more and more problems that the world is facing need to be tackled at the international level as mentioned above.
Globalisation of the world’s problems therefore has created a need for the concept of state sovereignty to be adapted. This will be discussed in the context of the rising loss of biodiversity in the next chapter.
State Sovereignty and human rights
International law usually focuses on issues that have an effect on the international community. Human rights treaties however care more about the implementation of international standards at the national level  . Human rights treaties are signed at the international level but there is no doubt that it is at the national level that its promotion and protection matters most. State sovereignty and the protection of human rights are therefore very much connected since individuals depend on the state for the protection of their rights and interests.
Before the Universal Declaration of Human Rights, individuals were not subjects of international law. The UDHR shaped the human rights movement and highlighted the fact that states have a role to play in the implementation of human rights. Thanks to the declaration, human rights are accepted today as being inherent to each individual and universal. The UDHR as well as the human rights conventions that followed identified the duties of a government for the implementation of those human rights. 
The term ‘human right’ has itself been the subject of various interpretations and classifications. One of the leading classifications of human rights is that of Czech jurist Karel Vasak- the Three Generation of rights. The first generation of right consists of civil and political rights  .The second generation consist of social, economic and cultural rights  . The third generation of rights is known as the collective rights. It focuses on the right of individuals to benefit from clean air, nature protection and so on. This third category of rights will be analysed later on in relation to nature conservation.
The human rights movement has often been believed to represent the right of states against the right of individuals. Is the concept of state sovereignty and human rights really fundamentally opposed? According to author Jack Connelly, the two are not opposed. He argues that human rights have transformed state sovereignty only to a limited extent. According to this view, for human rights to be respected and better recognised there is no need for the concept of state sovereignty to be weakened. Another author in favour of this theory Nguyen Duc Thang  asks whether human rights should be placed above the state’s “sacred" sovereignty.
In an attempt to reconcile the protection of human rights with state sovereignty, an enlightening paper entitled the ‘Two concepts of State Sovereignty’ was written by Kofi Annan in The Economist  . According to him, the concept of state sovereignty needs to be “redefined" to better protect human rights around the world. He argues that the only reason why state sovereignty and human rights are often seen as opposed is because intervention is believed to be only through the use of force. He therefore acknowledges that while sovereignty is an important concept, it needs to be changed to better protect individuals.
State Sovereignty and Environmental Degradation
Over the course of this century the relationship between human activity and our planet has changed fundamentally: Before the 20th century it was not possible for mankind to cause irrevocable changes to the environment. Today however, human activity can alter the environment radically.
For this reason, international environmental law emerged and became well established over the last ten years. However, two factors are believed to hinder its development. The most significant of these constraints is the concept of state sovereignty and its implication of absolute jurisdiction. In order to better protect the environment, once again this concept needs to be redefined. Also equally prejudicial to the environment is the fact that developing countries have other priorities than environmental protection.
For a long time, environmental law concentrated mainly on the responsibility of a state over its own territory. Nowadays with the devastations caused by trans-boundary pollution treaties take into consideration the protection of the wider environment. Indeed, environmental problems are closely inter-related. There is a risk that the actions of a few states might cause irreversible damages to the world environment.
Can heedless governments be sanctioned by neighbouring countries, non-governmental organizations, or intergovernmental organizations such as the United Nations? The justification for such intervention would be explained most simply using Mill’s Harm Principle  ; Nations have freedom to make choices within their own territory but they do not have the right to make choices that harm citizens in other countries, including harm from reckless environmental policies.
State responsibility for environmental degradation is a consequence of state sovereignty. At the same time, the limits of state power and responsibility must be recognized by the international community. Indeed, today more and more non-state actors are involved in making environmental choices.
States alone cannot therefore be expected to solve environmental issues. The complexity of environmental issues calls for cooperation between scientists, businesses, governments, and other actors including individuals. To do so within a context that acknowledges the political realities of the world is to do so in a way far more likely to be effective than the alternatives  according to Milan Ilnyckyj. He goes further to say that the sovereign state has many features that recommend it as the best agent to serve as environmental regulator.
For example, in the Trail Smelter Arbitration Case  of between the United States and Canada. Lead and Zinc production by a Canadian corporation was leading to significant sulphur dioxide emissions which were, in turn, leading to acid rain causing damage downwind in the United States. An International Tribunal was established to assess the situation and award damages. Ultimately, damages were paid to the United States by the Canadian company in question and restrictions were imposed upon the manner in which sulphur dioxide was to be treated and how much was to be released. This regulator mechanism was a result of state sovereignty and its power to bring states to repair damages they cause.
The state as the main agent responsible for nature degradation as well as its paradoxical potential to help conserve nature will be analysed in chapter 3.
Chapter 2 – Bioregionalism and Nature Conservation
Ecosystems around the world are interdependent. To protect endangered plant and animal species, bioregions must be cared for. The problem that arises here is that bioregions usually encompass the territory of more than one state. Geographically therefore, bioregions must be cared for irrespective of the territories they cross. There are many factors that make nature conservation difficult, in this chapter the need to care for bioregions will be analysed.
2.1 International Environmental Law and Nature Conservation
“If people want to live in a world that is more than pigeons, rats, cockroaches and starlings, we need to do more than set aside land. We have to protect endangered species before they are destroyed."
Carter Roberts 
International environmental law emerged in the 1970s, with the adoption of the Stockholm Declaration at the first international conference on the environment. 114 states attended the conference in order to analyse the world’s rising environmental concerns. The principles of the declaration are today the foundation of international environmental law: the precautionary principle, the polluter pays principle, the no harm rule and the principle of common but differentiated responsibility. A new concept also came to prominence in 1992 for the Rio Conference, that of sustainable development. International efforts to protect nature are today largely based on this principle of sustainable development.
The United Nations is the principle international institution responsible for formulating international environmental policies. Recent environmental conventions and protocols have been negotiated through the United Nations Environment Programme. In addition to UN bodies, a number of other organisations and NGOs influence environmental policies on the international field. Amongst these are the World Trade organization, the Organisation for Economic Co-operation and Development as well as NGOs such as the International Union for Conservation of Nature and Natural Resources which have an observer status in international negotiations.
The term ‘environment’ itself has different meanings. According to Albert Einstein, “the environment is everything that is not me." Under international environmental law the concept is restricted to all living and non-living natural organisms. The environment consists of the air, water, land, plant and animal species. It is contrasted to man-made structures. This dissertation is only going to focus on the protection and conservation of plant and animal species. However, it should not be forgotten that all components of what we term the “environment" are interdependent and that environmental issues are a reflection of a general degradation in the world’s environment.
As for the term “nature conservation," it traditionally encompasses the preservation of, the existence and welfare of animal and plant life. This also implies that it is necessary to preserve and enhance their natural and man-made habitats. Arguably, nature conservation can also include the conservation of natural landscapes for the aesthetic benefits they bring to mankind. This type of conservation is known today as landscape management  . In accordance with the holistic approach  to nature conservation, these two types of conservation are usually treated together. Natural landscapes or natural features are therefore treated as deserving of preservation irrespective of their functions as natural habitats.
2.1.1 The holistic approach to nature conservation
During the last 40 years since the development of environmental law, international environmental ideology has evolved. This evolution started with the most significant ‘soft law’ that resulted from the earth summit that is ‘Agenda 21.’ This has had an impact on our conception of the environment. Today, environmental law adopts a holistic approach to protection of the environment. For example, environmental law for a long time concentrated mainly on resource management and sustainable development. Today, countries around the world are called upon to achieve sound environmental management.
Unfortunately, this does not mean that it has been translated in state or individual actions. In politics, we often hear that the environment deserves protection for its own self. However, it is doubtful whether this is reflected in current environmental law. Indeed, the origin of environment was based around the anthropocentric  philosophy. This anthropocentric view implies that natural resources are to be exploited for the benefit of the human race. Under this conception of the environment, nature conservation is justified on the basis of stewardship that is the idea that we must preserve nature for the sake of future generations.
Two alternative philosophical approaches to nature conservation have also emerged: the biocentric and the ecocentric  approach. According to the biocentric  view, animals should be protected for their own sake because they co-exist with humans and are deserving of protection. The ecocentric approach goes further by valuing plant, animal and human life equally. All living forms of life are therefore seen as being part of the ecological system and having extrinsic value independently. Plants therefore also have a right to be protected irrespective of the use to which they are put by humans or animals.
Many equivalent theories have emerged over the years, such as the Deep Ecology philosophy which places humans within the context of ecological systems rather than outside or central to the system. In addition, humans are considered to be equal, not superior or more important, in value to other components of an ecological system  .
2.1.1 Biological Diversity
The most sophisticated and ambitious treaty on nature conservation is the Convention on Biological Diversity. It was signed in June 1992 in Rio de Janeiro at what became known as the Earth Summit by 150 state representatives  and came into force on the 29th of December 1993. The objectives of the convention are the conservation of biodiversity and the sustainable use of species. Biodiversity is defines under the Convention as “the variety of life in all forms  ." The Convention also goes further by subdividing the concept of biodiversity into three areas that is the diversity of ecosystems, diversity of species and genetic diversity between each species of plants and animals. However, for the purpose of this dissertation, this will not be considered in details.
According to scientists Erhlich and Wilson  , “Biodiversity is a precious genetic library maintained by natural ecosystems." However, the destruction of ecosystems is causing the diversity of species to diminish at an alarming rate. Also, increasing world population and demand for resources is making species at risk of being extinct. It has been estimated that around 70 per cent of the world’s fish stock for example are being harvested at levels near or beyond sustainability. It has also been estimated that the destruction of the tropical rainforests in South America is causing the extinction of two species every hour  . Is the situation really this alarming despite international efforts to protect our flora and fauna  ?
At present, more than 1.75 million species of plant, organisms and animals have been given scientific names  . Measuring species loss is not an easy task and the opinion of expects diverge. According to Professor Bjorn Lomborg, in his book The Skeptical Environmentalist, species loss in our lifetime is about 0.7 per cent rather than the 20 – 25 per cent mentioned in some reports  . He concludes that there are more reasons to be optimistic about the future of our environment. Despite the fact that views differ on the actual situation of our flora and fauna, this does not mean that we should not consolidate our efforts to preserve and restore our environment. After all, recent environmental disasters have proved that the world cannot sustain much more human-induced changes.
“Ecoregion-Based conservation (ERBC) recognizes that effective conservation requires thinking and planning at the spatial and temporal scales of the processes that generate and maintain diversity."
Gordon H Orians
Ecosystems have gained politically importance, since the Convention on Biological Diversity. The Convention defines "the protection of ecosystems, natural habitats and the maintenance of viable populations of species in natural surroundings" as a commitment of ratifying countries. This has had the effect of countries identifying ecosystems and distinguishing among them. The CBD defines an "ecosystem" as a "dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit".
The idea of Bioregionalism was first envisionned by Peter Berg and Raymond Dassmann in the late 1960s and early 1970s. They proposed the division of land based around a region were ecosystems were interdependent. This lead to the rising section in the ecological philosophy movement that came to be known as “bioregionalism.  " The concept envisions a redrawing of political boundaries to respect the contours of local bioregions. This view promotes the idea that human beings need to start functioning at a regional level in order to maintain sustainability of natural resources. Bioregionalism goes even further by encouraging the use of local foods and materials. Sustainability will then come from moderate cultivation and exploitation of local resources.
At the international level, no convention mentions bioregions. This is because at its core, bioregionalism does not tally with the principle of state sovereignty which is the basis of international law. The World Wide Fund  currently uses bioregionalism as a method to conserve nature. The fund has acquired wide spread recognition and is currently the world’s biggest NGO. Although recommendations from the fund have no force of law, it has become very influential. For example, the first North American Bioregional Congress took place in 1984 and was followed by other congresses. The role of the WWF in the promotion of the concept of bioregionalism is analysed below.
2.2.1 Ecosystems and Bioregions
Put simply, ecosystems consist of animal, plant as well as non-living organisms that dependent on each other through food webs. An ecosystem is relatively small and can be terrestrial, aquatic or man-made. Ecosystems are in turn interdependent. A group of ecosystems that dependent on each other for sustainability are known as ecoregions or bioregions. Bioregions usually have a biodiversity of plants, animals and other organisms that distinguish it from other bioregions. World Wide Fund has identified 867 terrestrial bioregions, and approximately 450 freshwater bioregions across the Earth.
The Global 200 is the list of bioregions identified by the WWF as priorities for conservation. According to the WWF, a bioregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species, dynamics, and environmental conditions  . The WWF has divided the 200 priority bioregions into three different categories according to their degree of endangerment: firstly there is the critical or endangered category, secondly the vulnerable category and lastly the relatively stable or intact. Today, over half of the bioregions in the Global 200 are rated endangered.
The only problem that arises very often is that a bioregion encompasses the territories of more than one state. One example worth analyzing is that of the Chihuahuan Desert. It is considered by the WWF as the world’s most biologically diverse desert. It is a large bioregion that is found primarily in Mexico but which includes part of Texas, New Mexico and Arizona in the United States. It is a region with a rich biodiversity that has been analysed by Mexican and American biologists for decades. However, for a long time it was a region that the WWF did not work with. This is because the desert is part of two countries with very different cultures and people.
There are various categories of bioregions or ecoregions. Terrestrial bioregions are land bioregions, as distinct from freshwater and marine bioregions. The WWF ecologists currently divide the surface of the earth into eight major ecozones.  These ecozones are the Afrotropic, Antarctic, Australasia, Indomalaya, Nearctic, Neotropical, Oceania and Palearct. These ecozones contain 867 smaller terrestrial ecoregions  .
The eight terrestrial ecozones are based around major floral and faunal boundaries that have been identified by botanists and zoologists. Ecozone boundaries generally follow continental boundaries or other major barriers to plant and animal distribution such as the Himalayas or the Sahara. Compared to bioregions, ecoregions are well recognized and are subject to far less disagreement.
As for marine bioregions, they are areas of relatively homogeneous species composition that can be distinguished from other systems. They are sufficiently large in size and are composed of species that are interdependent and linked by food webs. They have been defined by the WWF as well as The Nature Conservancy (TNC) to aid in conservation activities for marine ecosystems. Forty-three priority marine bioregions are currently recognized as part of WWF’s Global 200 efforts.
Lastly, we have freshwater bioregions. They are large areas encompassing one or more freshwater systems that contain a distinct assemblage of natural freshwater plants and animals. Freshwater systems include rivers, lakes, wetlands and streams. The WWF identifies twelve major habitat types of freshwater bioregions: Large lakes, large river deltas, polar freshwaters, mountain freshwaters, temperate coastal rivers, temperate floodplain rivers and wetlands, temperate upland rivers, tropical and subtropical coastal rivers, tropical and subtropical floodplain rivers and wetlands and oceanic islands.
Bioregions in each of the above mentioned categories have been classified according to specific principles. The aim behind the identification of bioregions by the WWF and the TNC was to make efforts to conserve nature more effective by respecting nature’s own ecological boundaries. The principles behind bioregionalism are analysed below.