Introduction to soil biodiversity Flashcards
What percentage of species on Earth are soil-dwelling?
59% (±15%)
Name two groups that comprise a substantial part of soil biodiversity
Bacteria and phages
What are three major reasons that it is difficult to estimate soil species richness?
Limited data, variable methodologies, and geographic biases
What are three major reasons of the importance of soil in international strategies for biodiversity conservation?
Role in supporting ecosystem services, resilience to environmental change, and sensitivity to global factors
What did a 2015 study conclude about soil resources?
Majority of soil resource are in fair/poor/very poor condition due to human activity
What did a 2015 study conclude about land?
33% of land is moderately to highly degraded
What did a 2015 study conclude about topsoil?
25–40bil tonnes of topsoil is lost to erosion per year
How long does it take to produce a metre depth of soil?
10,000 years (degradation>production therefore it is a non-renewable resource)
How much carbon is stored in soil?
2.5 trillion tonnes (3rd largest carbon store)
What do the UK government aim to do by 2030?
Ensure sustainable management of soil and establish sufficient data to understand the current state of soil health
What are the four classifications of soil-dwelling organisms (based on body size)
Microflora, microfauna, mesofauna, macrofauna
Give two examples of microflora
Bacteria and archaea
Give two examples of microfauna
Nematodes, protozoa
Give an example of mesofauna
Microarthropods
Give three examples of macrofauna
Worms, termites, millipedes
Describe the microbial biomass in soil
Most abundant and diverse group in soil. Primary consumers.
What are the four primary roles of the soil microbial biomass?
Breakdown of complex organic material, nutrient transformation, structural stability, symbiotic relationships (mycorrhizal fungi and N fixing)
Describe soil fauna
Secondary and high order consumers
Give four examples of fine-scale abiotic properties of soil
Porosity, water, temperature, pH
What is rhizodeposition?
The deposition of amino acids and sugars in the soil adjacent to the plant root that stimulates microbial abundance and diversity
What are the two main plot-to-field scale categories
Resource quality and human disturbances
What are the two categories of soils in terms of resource quality?
Mull soils and mor soils
Describe mull soils
Fertile, neutral pH soils with high abundance of bacteria and bacterial-feeding fauna and earthworms
Where and how are mull soils produced?
Deciduous forests with high litter nitrogen, low lignin and phenolics (protects plants from herbivores)
Describe mor soils
Infertile, acidic soils. Absence of earth worm, high abundance of fungi, microarthropods/enchytraeids (annelids).
Where and how are mor soils produced?
Coniferous forests with low litter nitrogen, high lignin and phenolics
Give three examples of human impacts on soil
Intensive agricultures, climate change, increasing aridity
