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.






Дата добавления: 2016-07-18; просмотров: 1306; ЗАКАЗАТЬ НАПИСАНИЕ РАБОТЫ


Поиск по сайту:

Воспользовавшись поиском можно найти нужную информацию на сайте.

Поделитесь с друзьями:

Считаете данную информацию полезной, тогда расскажите друзьям в соц. сетях.
Poznayka.org - Познайка.Орг - 2016-2022 год. Материал предоставляется для ознакомительных и учебных целей.
Генерация страницы за: 0.018 сек.