Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
biology-textbook-new basic.doc
Скачиваний:
1
Добавлен:
01.05.2025
Размер:
3 Мб
Скачать
☆

7. Biodiversity as phenomenon of life

Outline: biodiversity conservation, legal system, sustainable development, use of natural resources, biomes, ecosystems, population, species, conventions, econet (ecological network), landscapes.

Introduction

All previous evolution of mankind resulted in exhausting use of nature resources including biodiversity, high level of environmental pollution, harmful impact on human health, deterioration of biocoenoses, landscapes and ecosystems and is lacking in prospects. In spite of extraordinary efforts of international environmental community and a large number of the international and regional initiatives reflected in conventions, programmes and projects, the deterioration of bio- and landscape diversity is increasing since uncompensated impressments or destruction of ecosystems and nature resources is continuing for the transient benefit of human population or as a result of its activity.

7.1. Biodiversity and problems of its preservation

Biodiversity means the variety of life forms on the planet. During last 30 years, researchers and public leaders came to understanding that evident threats to biodiversity are threats to humanity.

In 1992, representatives of 150 states have signed the Convention on Biological Diversity (CBD) during the Earth Summit in Rio-de-Janeiro, Brazil. 187 states and European Union have ratified the CBD and integrated this legally binding international treaty in national legal systems, which is an evidence of crucial importance of the biodiversity for the planet and for human life and development.

Thus, juridical status was given to the term “biological diversity” practically everywhere. The CBD provides following definition of this term: "Biological diversity" means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems». Fundament of biodiversity is based on species, which are discrete communities of living organisms having the same set of genes (genotypes) and capable to reproduce organisms similar to themselves.

Complex of living organisms of different species, which are in interactions with surrounding environment and each others in order to exchange the energy and substances, represents ecosystem. Sustainability and evolution of the ecosystems depends on the balance of the processes of assimilation and dissimilation of the energy and substances as well as on organisms’ resistance and adaptability to external impact.

General scheme of the levels and composition of biodiversity is depicted in the table 7.1.

Table 7.1.

Biodiversity components and levels (Global, 1995)

Ecological diversity

Genetic Diversity

Organisational diversity

Biomas

Kingdoms

Bioregions

Phylum

Landscapes

Families

Ecosystems

Genus

Habitats

Species

Niches

Subspecies

Populations

Populations

Populations

Individuals

Individuals

Chromosomes

Genes

Nucleotides

Cultural diversity: Human relations at all levels

Totality of the ecosystems constitutes special part of the planet occupied by living organisms which are key peculiarity of this field. The term biosphere was given to this part of the planet.

From human point of view, biological productivity is key characteristic of ecosystem. Biological productivity depends on the composition of biodiversity and environmental conditions. From human point of view, natural environment is a source of raw materials for processing the food, clothes and footwear, construction of dwellings, means for health treatment and other purposes. According to the definition given in the Convention, “biological resources” includes genetic resources, organisms or parts thereof, populations, or any other biotic component of ecosystems with actual or potential use or value for humanity.

As it follows from the table 7.2, about 1.75 mln species of living organisms are discovered and described by present. However, according to modern scientific assessments, this constitutes only the eighth part of total biodiversity of the planet and many new species will be discovered in future.

Table 7.2.

Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]