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The biosphere (which is technically a spherical shell) is virtually a closed system with regard to matter, [1] with minimal inputs and outputs. Regarding energy, it is an open system, with photosynthesis capturing solar energy at a rate of around 100 terawatts. [2] By the most general biophysiological definition, the biosphere is the global ...
Biodiversity is commonly measured in terms of taxonomic richness of a geographic area over a time interval. In order to calculate biodiversity, species evenness, species richness, and species diversity are to be obtained first. Species evenness[ 181 ] is the relative number of individuals of each species in a given area.
The term was suggested in 1916 by Clements, originally as a synonym for biotic community of Möbius (1877). [4] Later, it gained its current definition, based on earlier concepts of phytophysiognomy, formation and vegetation (used in opposition to flora), with the inclusion of the animal element and the exclusion of the taxonomic element of species composition.
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. [1] Phytogeography is the branch of biogeography that studies the ...
The biosphere is postulated to have developed, from the origin of life onwards, at least some 3.5 billion years ago. [74] The earliest evidence for life on Earth includes biogenic graphite found in 3.7 billion-year-old metasedimentary rocks from Western Greenland [ 69 ] and microbial mat fossils found in 3.48 billion-year-old sandstone from ...
e. An ecosystem (or ecological system) is a system that environments and their organisms form through their interaction. [2]: 458 The biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal factors. External factors such as climate, parent material which ...
Prior to The Origin of Species, there was little appreciation or understanding of the dynamic and reciprocal relations between organisms, their adaptations, and the environment. [231] An exception is the 1789 publication Natural History of Selborne by Gilbert White (1720–1793), considered by some to be one of the earliest texts on ecology. [248]
Biological organisation is the organisation of complex biological structures and systems that define life using a reductionistic approach. [1] The traditional hierarchy, as detailed below, extends from atoms to biospheres. The higher levels of this scheme are often referred to as an ecological organisation concept, or as the field, hierarchical ...