stability and change

• Stability is the ability to maintain or support systems and processes continuously over time
• Stability for ecosystems can mean consistent supply of sunlight or energy, deprivation of disturbances that can affect the ecosystem negatively, climates within tolerance limits, high genetic diversity creating increased changes to survive selection, and consistent nutrient cycling without leakages
• Many ecosystems keep this stability without human disturbance/management ex. The Bödmerenwald in Kanton Schwyz in Switzerland arising 7000 years ago
• Erosion is a disturbance that can lead to a loss of nutrients during nutrient cycling, threatening stability
• Harvesting and removal of materials disrupts nutrient cycles and food webs
• Poaching and selective removal disrupts ecosystems structures and food webs, especially in the case of a targeted keystone species
• The tipping point for ecosystem stability signifies the point at which its reversal might be difficult or impossible
• Positive feedback loops drive ecosystems to achieving new forms of stability and equilibrium by amplifying effects
• The water cycle dictates the amount of water transpired and returned to the air as moisture. Less trees make less moist wind which means the deforestation of the Amazon has caused an increase in river discharge by 20%. This creates dry air that is more concentrated with carbon and leaves trees dry and easy to spark fire.
• Primary forests are the densest forest and the most ecologically diverse
• Tropical tree covers maps the trees inside and outside of dense forests across tropics
• Peatland is the wet-land of decaying plants and incompletely decomposed organic materials
• Tree cover is where tree patches cover more than 1 hectare and provide shade
• Land cover is the observed physical cover of vegetation, etc.
• Mesocosms are small experimental areas to model ecosystems that are completely sealed up and closed with only light entering as energy
• A keystone species is one that is critical to the survival of other species in a system
• Sustainability is the responsible maintenance of ecological systems so that there is no reduction of conditions for future generations, ensuring long-term viability of a system.
• Finnish forests have provided food, shelter, employment, and income for native persons and its Forest Act provides a framework for forest management with the leading principle of obligation to regenerate after logging
• Soil erosion is caused by the tillage and plowing and harrowing of land which decreases soil quality and affects agricultural yields
• Fertilizers increase crop yields but decrease natural nutrients in the soil and can sink into the soil and leach into water systems, bringing it excess nitrogen and phosphates, prompting eutrophication
• Leaching allows for soil exposure during rain to wash away nutrients and makes plant unable to access them, impacting agricultural yields
• Carbon footprints are created by agricultural machines and glasshouses creating power in the form of CO2 and leaving footprints
• Monoculture agriculture is practicing the growth of only one type of plant which prompt the same pests and creates pollution with prompted use of pesticides
• Natural eutrophication occurs through gradual drying up pools of water which disproportionally increases the amount of nutrient rich sediments.
• In artificial eutrophication, it is caused by the leakage of excess chemicals used in the agriculture which is digested by marine organisms in the water bodies and broken down into nitrogen and phosphates that autotrophs use to boost their growth
• Biological oxygen demand (BOD) indirectly denotes the amount of pollution in aquatic system because more will need more oxygen to be broken down by organisms to absorb their nutrients
• BOD is measured by taking a measured volume of water from a source and measuring the dissolved oxygen content on day 1 in ml/L using an oxygen probe and then placing it in the dark at 20 celsius for 5 days to prevent photosynthesis and measuring it again. The difference between the two measurements is the BOD.
• As eutrophication increases, more algae blooms, increasing oxygen demand
• Less oxygen being available for marine species means the environment changes and becomes more competitive, leading to the depletion of certain species and hence changes the food chain
• Bioaccumulation is the increase in the concentrations of a toxin in body tissues during an animal's lifetime happening with fat soluable chemicals which cannot be excreted
• Biomagnification is the increase in the concentration of a chemical at each successive trophic level in a food chain- used by predators to accumulate higher chemicals of a toxin than their prey.
• Top predators like shark, swordfish, mackerel, cod, and bluefin tuna consume many prey like shellfish containing traces of mercury in droplets of fat in adipose tissue. With every added trophic level, more prey is consumed than before, causing increasing accumulation of mercury through biomagnification meaning top predators have a lot
• Macroplastics are large, visible, and larger than 5mm in size
• Microplastics are extremely small pieces of plastic debris less than 5mm
• Bioaccumulation can cause high levels of non-degradable microplastics in predators high in the trophic food chain
• Plastic fishing gear can often wear with time and are disposed of. Over time, they break into microplastics that are hard to recover and manage
• Microplastics are in "treated" water, salt spray, biosolids (organic matter recycled from sewages and used in agriculture), and storm water runoffs
• Rewilding is used to encourage natural ecosystems to return to their natural state by returning land and oceans to more natural states by doing nothing like in the Hinewai reserve in New Zealand
• Rewilding can include distributing seeds of plants of endemic (native) species, reintroduce apex predators and keystone species to an ecosystem, restablishing connectivity between fragmented parts of an ecosystem, controlling invasive species populations and removal of livestock that can increase speed of rewilding process
• Sources of gene variations can come from random mutations or random fertilizations