glossary part 2 Flashcards
(44 cards)
• Disturbance
A temporary and relatively discrete change in an ecosystem that causes pronounced changes in the ecology.
• Disturbance Regime
= The pattern of disturbances that shape ecology over a medium to long time-scale. Disturbance regimes are typically thought of as occurring on an ecological rather than evolutionary time-scale
• Anthropogenic =
(chiefly of environmental pollution and pollutants) originating in human activity
• Deciduous =
shedding its leaves annually
• Succession =
non-seasonal, directional and continuous patterns of vegetation change including colonisations and extinctions
• Primary forest
= native tree species, where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed
• Primary succession
= large-scale event → bare surface, no soil, e.g. glacial retreat, or new volcanic surface.
• Secondary succession =
= disturbance has not removed the substrate, e.g. fire, insect plague, land clearance. A biological legacy is left behind…
• Allogenic =
= seeds or plants arising from external sources eg. birds and animals
• Autogenic =
seeds and plants that self-generated from biological processes
• Secular succession
= Long-term changes in a landscape as a result of long term environmental change
• Forest physiognomy
o Ecological physiognomy encompasses the physical structures of an ecology
o Forest physiognomy is dominated by tree and understory structure
• Tree architecture:
o They physical features of a tree
o Not all trees are built the same
o Height and breadth of trunk, crown width, root depth, presence or absence of buttress, tap or stilt roots
• Buttress
o Very important for trees as strengthens and supports tree, Stops erosion
• Epiphyte
o A plant growing in another plant
o Often but not always parasitic as well as photosynthetic
• Hemiepiphyte:
o An epiphytic plant that starts in the crown of a tree or plant and grows roots down to the soil
o Example is a strangler fig
• Secondary Hemiepiphyte:
o An epiphytic plant that starts growing on the ground and then grows up the side of a tree into the leaves
o Often only uses the tree for structural support
• Canopy layer
o Continuous, largely unbroken layer of tree crowns
o Canopy layer tends to be continuous and dense
• Emergent layer:
o Occasional emergent species break above the canopy layer
• alpha richness
= number of species present
• beta richness/diversity
= rate at which species change between habitats
• gamma diversity =
= biogeographical diversity, total species diversity in a broad region
• Non-frequency dependent models
(model / hypothesis is independent of any relationship between species abundance and their growth, recruitment and mortality etc)
• Frequency dependent models =
model / hypothesis depends on / is interwoven with relationship between species abundance and their growth, recruitment and mortality etc)
