Definitions Flashcards
5 different mapping approaches
Geographic ranges - centers of endemism Absolute species number - hotspots Floristic compositions and land use - associations Satellite - vegetative units Climate - biomes
Disjunct
Taxon with distribution where it has two or more groups that are related but are widely separated geographically
Near-endemic
Species whose range extends only marginally outside South Africa
Endemism
Ecological state of a species being unique to a defined geographical location
Neoendemism
Species that have recently arisen, through divergence and reproductive isolation or through hybridization and polyploidy in plants
Paleoendemism
Species that were previously widespread but are now restricted to a smaller area
Holoendemism
Endemic in entire population or a given area
Cosmopolitan
A toxin whose range extends across most of the world in appropriate habitats
Vicariance model
More of separation that occurs when biological population of same species become isolated from each other
Hotspot
An area with high biodiversity but is also threatened by human activity
Species richness of SA and Southern Africa
24000 - >70% endemism
30000 - 60% endemic
Sub-Antarctic tundra
PEI Cold, windy, wet(2000-3000mm) Low diversity Bryophytes - mosses, liverworts + cushion and mat forms (no trees) 100% conserved
Sub-Antarctic veg units
Coastal veg Biotical herbfield + grassland Fernbrake Mire Drainage line + spring veg Cinder stone Fellfield Polar desert
Nama Karoo
Continental climate with unpredictable late summer rain (100-400mm) - east to west gradient
Temp: high summer, low winter
Bioregions: bushmanland, upper/lower Karoo
1% conserved
2200 species
Nama Karoo dominant families
Asteraceae, fabaceae, poaceae
Lack of dom in succulents (too cold), perennial grasses (too dry), (no) trees (too dry + soil too shallow)
Desert
Net moisture deficit Characterized by therophytes (annuals) High diversity 20% conserved Fairy circles
Desert families
S Namib: (Nama Karoo) - Aizoaceae, crassulaceae, Zygophyllaceae
Gariep: (succulent Karoo) - poaceae, acanthaceae, amaranthaceae
Succulent Karoo
Arid climate (100-200mm)
Unpredictable largely winter frontal rainfall + coastal fog
Warm temp
V diverse - 6356 species (38% endemic, 17% red listed)
5.8% conserved
Skip international conservations effort
Succulent Karoo bioregions
Richtervel
Namaqualand
Knersvlakte
Rainshadow valley
Succulent Karoo families
Succulents: Aizoaceae, Crassulaceae, Euphorbiaceae
Geophytes: iridaceae, hyacynthaceae
Daisy: asteraceae
Rangeland degradation
The loss of biological and economical productivity of a region mainly as a result of human activity
Desertification
Range degradation in arid, semi-arid, and dry sub-humid climatic regions as a result of several factors, mostly human activities
Bush encroachment
The invasion and/thickening of aggressive undesired woody species resulting in the imbalance of grass:bush ratio, a decrease in biodiversity, carrying capacity and concomitant economic loss
Types of range degradation (7)
Loss of vegetation cover Changes in species composition (loss of palatable species) Bush encroachment Deforestation and over-harvesting Alien plant invaders Industry and development Global climate change
Rangeland restoration
Passive - resting by removing livestock Active: Reseeding Partial clearing Constructing resource traps Reducing erosion and improving infiltration
