ecology

• A habitat is the place where an  organism lives, which could be both in  terms of its geographical as well as its  physical location within an ecosystem.
• An ecosystem consists of all living things (biotic factors) that live together with their non-living surroundings (abiotic factors).
• Biotic factors are “living” factors which  have impact on feeding, predator-prey, symbiotic, mutualistic or other forms of  interdependent relationships.
• Abiotic factors are ”non-living” physical  factors. They have an influence on  specific adaptations of organism to live  in their respective habitat.
• Plant distribution and adaptation is affected by temperature, water availability, light intensity, soil pH, soil salinity and the availability of mineral nutrients. 
• According to the law of tolerance, populations have optimal survival conditions within critical minimal and maximal thresholds. As a population is exposed to the extremes of a particular limiting factor, the rates of survival begin to drop
• Under the law of tolerance bell-curve, the zones of intolerance are the outermost regions in which organisms cannot survive (represents extremes of the limiting factor).

  
• Under the law of tolerance bell-curve, the zones of stress are regions flanking the optimal zone, where organisms can survive but with reduced reproductive success.

  
• Under the law of tolerance bell-curve, the optimal zone is the central portion of curve which has conditions that favour maximal reproductive success and survivability.

  
• An ecosystem is the interaction of living and non-living things within an area (i.e. a community and its abiotic environment).
• A biome is a geographical area that has a particular climate and sustains a specific community of plants and animals.
• The main factors affecting the distribution of biomes is temperature and rainfall.
• Biomes like tropical rainforests are hot and humid environments near the equator with dense vegetation and high biodiversity.
• Biomes like taigas are coniferous forests near the poles that have cold temperatures and little precipitation (moisture trapped as snow / ice).
• Biomes like deserts are dry and arid environments that display extreme temperature conditions (hot and cold).
• According to the Whittaker climograph, deserts typically have high average temperatures but low precipitation (hot and dry).
• According to the Whittaker climograph, rainforests typically have both high average temperatures and high precipitation (warm and wet).
• According to the Whittaker climograph, taigas typically have low average temperatures and reasonably low precipitation (cold and icy).
• Animal distributions are affected by abiotic factors such as water  availability and temperature.
• Plant distributions are affected by temperature, water availability, light

  intensity, soil pH, soil salinity and the availability of mineral nutrients.
• Coral reefs are biodiverse marine ecosystems made from zooxanthellae that require certain abiotic factors to form. This includes low depth, clarity and salinity of water, a pH of above 7.8 and warm temperature.
• A population is a group of organisms of the same species who live in  the same area at the same time able to interbreed with each other.
• A community is a group of  populations living together in an area and interacting with each other.
• Relationships within a community can be intraspecific or interspecific,  depending on whether relationships occur between members of the  same species (intra-) or members of different species (inter-).
• Species are groups of organisms that can potentially interbreed to produce fertile offspring.
• Autotrophs are organisms that use solar energy or chemical energy to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment.
• Saprotrophs are heterotrophs that obtain organic nutrients from detritus (dead matter) by external digestion.
• Inorganic nutrients are chemical elements, compounds, and other substances necessary to sustain life processes that are not chemically carbon-based.
• Quadrant sample is a square or rectangular plot of land marked off at random to isolate a sample and determine the percentage of vegetation and animals occurring within the marked area.
• Interbreeding is when two members of the same species mate and produce offspring.
• Mesocosm is an experimental tool that brings a small part of the natural environment under controlled conditions.
• Sustainable communities are communities that are capable of being maintained at a steady level without exhausting natural resources or causing severe ecological damage.
• Detritivores are heterotrophs that obtain organic nutrients from dead organisms by internal digestion.
• Chi-squared test is a statistical test of the fit between a theoretical frequency distribution and a frequency distribution of observed data for which each observation may fall into one of several classes.
• Heterotrophs are organisms that gets its organic nutrients by feeding on autotrophs or other heterotrophs.
• Consumers are heterotrophs that feed on living organisms by ingestion.
• Crossbreeding is when members of different species breed together.
• Invasive species (or alien species) are species that are not native to an area or habitat.
• Endemic species are species that are native to a certain area or habitat.
• Stability refers to the ability to maintain or support systems and  processes continuously over time.