Māris kļaviņŠ, azamat azizov, JĀnis zaļoksnis environment, pollution, development: the case of uzbekistan

Figure 4.6. 
Hierarchy of 
ecosystems
Figure 4.7. 
Boundary 
between the forest and 
meadow ecosystems 
makes a forest edge 
ecotone – brushwood, 
which contains both 
forest and meadow 
species

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52 
ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
Within an ecosystem, there are extremely diverse bonds or 
interrelations  between  different  species  and  elements  of  inorganic 
nature. These bonds are much closer within a single ecosystem 
than  between  different  ecosystems.  There  is  no  question  that  the 
most important of these relations are food or trophic (from the 
Greek trophe, ‘food’) relations, when one species consumes another 
species as food. For instance, there are trophic relations between 
herbivore species and plant species, between predators and their 
prey, between parasites and their host species. However, there are 
other forms of relations among species apart from the trophic bonds. 
These relations can be, for example, mutually beneficial or symbiotic 
(Figure 4.8), or they can be just the opposite – competition among 
species for food resources or a habitat.
There also are other types of inter-species relations: when one 
species  subsists  on  the  food  leftovers  from  another  species,  finds 
habitation at places inhabited or forsaken by another species or just 
accidentally warns another species about imminent danger.
Secondary predators
Herbivores
Primary predators
Green plants
Excrements,
dead plant and animal material 
Saprophages
The trophic relations among species make the structural basis 
of ecological food chains and food webs (Figure 4.9). Energies and 
substances  flow  through  ecological  food  chains.  Green  plants  are 
the  primary  producers  that  make  the  first  link  of  the  food  chain.