a species that has an essential role in maintaining ecosystem structure is called a heterotroph.
a species that has an essential role in maintaining ecosystem structure is called a heterotroph.
a species that has an essential role in maintaining ecosystem structure is called a?
heterotroph
classic studies in kelp forest ecology have largely focused on trophic interactions (the relationships between organisms and their food webs), particularly the understanding and top-down trophic processes. bottom-up processes are generally driven by the abiotic conditions required for primary producers to grow, such as availability of light and nutrients, and the subsequent transfer of energy to consumers at higher trophic levels. for example, the occurrence of kelp is frequently correlated with oceanographic upwelling zones, which provide unusually high concentrations of nutrients to the local environment. this allows kelp to grow and subsequently support herbivores, which in turn support consumers at higher trophic levels. by contrast, in top-down processes, predators limit the biomass of species at lower trophic levels through consumption. in the absence of predation, these lower-level species flourish because resources that support their energetic requirements are not limiting. in a well-studied example from alaskan kelp forests, sea otters ("enhydra lutris") control populations of herbivorous sea urchins through predation. when sea otters are removed from the ecosystem (for example, by human exploitation), urchin populations are released from predatory control and grow dramatically. this leads to increased herbivore pressure on local kelp stands. deterioration of the kelp itself results in the loss of physical ecosystem structure and subsequently, the loss of other species associated with this habitat. in alaskan kelp forest ecosystems, sea otters are the keystone species that mediates this trophic cascade. in southern california, kelp forests persist without sea otters and the control of herbivorous urchins is instead mediated by a suite of predators including lobsters and large fishes, such as the california sheephead. the effect of removing one predatory species in this system differs from alaska because redundancy exists in the trophic levels and other predatory species can continue to regulate urchins. however, the removal of multiple predators can effectively release urchins from predator pressure and allow the system to follow trajectories towards kelp forest degradation. similar examples exist in nova scotia, south africa, australia and chile. the relative importance of top-down versus bottom-up control in kelp forest ecosystems and the strengths of trophic interactions continue to be the subject of considerable scientific investigation.
kelp forest
biodiversity (an abbreviation of "biological diversity") describes the diversity of life from genes to ecosystems and spans every level of biological organization. the term has several interpretations, and there are many ways to index, measure, characterize, and represent its complex organization. biodiversity includes species diversity, ecosystem diversity, and genetic diversity and scientists are interested in the way that this diversity affects the complex ecological processes operating at and among these respective levels. biodiversity plays an important role in ecosystem services which by definition maintain and improve human quality of life. conservation priorities and management techniques require different approaches and considerations to address the full ecological scope of biodiversity. natural capital that supports populations is critical for maintaining ecosystem services and species migration (e.g., riverine fish runs and avian insect control) has been implicated as one mechanism by which those service losses are experienced. an understanding of biodiversity has practical applications for species and ecosystem-level conservation planners as they make management recommendations to consulting firms, governments, and industry.
ecology