U2T6 - Keywords Flashcards
Biodiversity
Reflection of num of species in area + how evenly distributed some nums of living organisms are spread across range of species present.
Intensive Agricultural Practices
Practices which maximise productivity (increased food production) + profit. Pesticides wipe out herbivores eating crop, fertilisers improve crop growth + monocultures more profitable than polycultures. Help farmers meet demands + ensure agriculture remains viable. Biodiiversity costs to this.
Pest
Organism which damages valuable/commercial crop species + causes economic damage. An organism that causes economic damage/harm to human health.
Herbicides
Pesticide used for weeds/competitor plant species.
Polyculture
Involves growing more than one crop in same area of land. One method involves planting 2 crops in a field during 1 growing season, one planted after other is harvest. Another is planting 2+ crops in field at same time e.g. alternate rows. Crop rotation also counts.
Monoculture
Growing just 1 crop (often 1 variety of said crop) in an area. Doesn’t improve biodiversity as 1 food source available so narrow consumer range. Very common to extreme levels. Relies on fertiliser + pesticides. More susceptible to pests + disease. Profitable as simple. 1 crops’s need can be focused on so farmer specialist in 1 type of production so max yield. Easy harvest as it’s automated.
Crop Rotation
Changing crops grown in a field from 1 year to next. Avoids depletion of certain minerals from soil as each crop has own mineral profile it needs. Pest population less likely to establish itself + reduces fertiliser need. Variety of habitats + food sources. Reduces pesticide need. Needs more expertise + technical knowledge than monoculture due to variety + changes in soil minerals harder. Improves soil fertility.
Hedgerow Conservation + Maintenance
Important habitats for many species so maintenance needed for biodiversity. Provide shelter + act as wildlife corridors. Regulations + guidelines ensure they’re diverse + viable. Can hinder machinery movement between fields.
Biological Control
Alternative to using pesticides + involves introducing a predator to target a pest. Pesticides may eliminate natural predator so high chance of pest resurgence. May also release sterile males to reduce reproduction e.g. screw worm fly eradicated. Requires lots of prior expensive research.
Predator strips at field margins
Uncropped/ungrazed margin of approx 1m around field edge to establish area of relatively diverse plant life, including grasses.
Bioaccumulation
Pesticides which don’t naturally break down in environment can result in this. It remains in/on body of invertebrate + as materials pass through food chain, becomes more concentrated in tissues at each trophic level. Can reach toxic levels in top carnivores + increase mortality.
BOD
Biological/biochemical Oxygen Demand. Amount of O2 required by bacteria to metabolise organic material in water sample. Indicates water quality. Expressed as milligrams of O2 per litre of water.
Slurry
Mix of manure, water + other farm waste. Contains large amounts of organic + inorganic nutrients so provides readily utilisable form of nutrition for population of decomposing bacteria + quickly leads to population explosion of these. Creates simultaneous, rapid BOD increase. Decomposer pop decreases in time, once resources used up.
Silage Effluent
V.concentrated. Liquid produced in process of making silage, where crops harvested for cattle fodder are left to ferment anaerobically to make material more easily digestible by livestock. Up to 30l per tonne of silage per day can be produced + farmers must have procedures in place to manage this waste.
Fertiliser Run-Off
Artificial fertiliser contains highly soluble inorganic nutrients (phosphates + nitrates) Fast acting + easily utilisable by crop plants it’s sprayed on. Easily washed into waterways where it can cause mineral enrichment (eutrophication) which provides habitat for microscopic algae growth resulting in algal bloom. When they die, they’re decomposed by bacteria. Large vol dead matter so lots of decomposing bacteria. BOD increases (slower than slurry/silage, longer lasting as source is diffuse + on-going)
Eutrophication
Excess nitrates + phosphates leaching into waterways cause algal bloom in lakes + rivers, algal blooms prevent light from penetrating through water to plants at lower levels, plants below die due to lack of light + decomposed by saprobiotic bacteria, saprobiotic bacteria use up O2 in aerobic resp + other organisms die (fish, invertebrates) due to lack of O2 which decreases biodiversity.
ASSI
Areas of Special Scientific Interest. Ecologically important areas which is managed through govt directives in cooperation with landowners.
SACs
Special Areas of Conservation. Areas which have been given special protective status under EU Habitats Directive.
Biodiversity Action Plans
Discussed + issued by local councils + involves meeting, projects, activities, working with conservation groups etc to develop policies + activities at local council level.
Department of Agriculture, Environment + Rural Affairs (DAERA) agri-environment schemes
Provide financial support to farmers + landowners to encourage farmers to maintain rare habitats, remove invasive plants etc to increase biodiversity.
Northern Ireland Priority Habitat + Species List
DAERA required by Wildlife + Natural Environment Act to provide info for list identifying priority species + habitats which require conservation. Info used by other bodies (e.g. Council Planning Depts) to judge activities impact on environment.
The Greenhouse Effect
CO2 + other greenhouse gases (inc. thane + nitrous oxide) form layer in atmosphere that traps heat. Short wave radiation (visible light + UV light) from sun reaches earth’s surface, long wave radiation is emitted from earth’s surface into atmosphere. Some of this is trapped by greenhouse layer, reflected back + retained in atmosphere.
Estuarine
An estuary is the place in the water where a tide and a river current meet,
Organic Pollution
Pollution of water by organic material. e.g. sewage, slurry + silage effluent.
Permafrost
Subsoil that remains below freezing point throughout the year, occurring mainly in polar regions. As it thaws, bacteria become active, decomposing organic material in soil + contributing lots of CO2 + methane to atmosphere, increasing global warming.
Organic Fertiliser
Fertilisers derived from animal matter (animal poo/manure)
Pesticide
Substance used for destroying organisms harmful to cultivated plants or animals.
Leach
To drain away from soil by percolating liquid, especially rainwater.
Anoxic
When a river is totally lacking oxygen.
