Some example titles from 2007 Final essay writing The Effectiveness of Reintroducing Przewalski's Horses into the Mongolian Wilderness as a Protection Measure Against the Species' Extinction Global Warming: Should we be worried and what can we do to help? Title of essay Fire or Silviculture: What’s really harming the Flatwoods Please write a short paragraph why you write Salamander about the chosen topic. Effects of habitat degradation and deforestation on the endemic flora and fauna of Madagascar The effectiveness of protected land on biodiversity Due date: March 25th Conserving the North Atlantic right whale, Eubalaena glacialis Invasive Species and their Impact on Natural Habitats. Invasive species Invasive species Basics Basics Predicting invasions How big is the problem? Managing invasions Definitions How do invasives move/spread? Effects of invasives Predicting invasions Managing invasions How big is the problem? A few exotics in Florida Second largest cause of extinction: Hydrilla ( Hydrilla verticillata ), from Sri Lanka 4500 exotic species in the USA (exotic=non-native) Water hyacinth (Eichhornia crassipes) [OTA 1993] Australian paperbark tree ( Melaleuca quinqueneria ) More than 25% of all plants in Florida are non-native Brazilian pepper (S hinus terebinthifolius ) Chinese tallow (Sapium sebiferum)
Water hyacinth Hydrilla Brazilian pepper tree Paper bark tree Definitions Introduced (exotic) species = a species living outside its native range Invasive species = introduced species with dramatically expanding populations Chinese tallow
How invasives move/spread Stow-aways (e.g. ballast water)
Gypsy moth How invasives move/spread 1900 Stow-aways Commerce/Curiosity 1934 1994 Introduced 1868/1869
Rana ridibunda (lake frogs) How invasives move/spread were accidentally introduced at several places in Switzerland and France Stow-aways Commerce/Curiosity Specialty food Recreation Academic education Introductions for recreation How invasives move/spread Stow-aways Commerce/Curiosity Recreation Aesthetics http://natuurbeleving.scene24.net/zoogdieren/Wild_Zwijn_Sus-scrofa.html Sus scrofa , wild hog European Starling How invasives move/spread Stow-aways Commerce/Curiosity Recreation Aesthetics Biological control The European starling was first introduced to the United States in New York City, in 1890. Inspired by William Shakespeare's plays, Eugene Scheffland let loose one hundred starlings in Central Park.
Cane toads in Australia Cane toads in Australia Cane toads were deliberately introduced to Australia from Hawaii in 1935 in an attempt to stop French’s Cane Beetle and the Greyback Cane Beetle from destroying sugar cane crops in North Queensland. The Australian Bureau of Sugar Experimental Stations made the release of 101 cane toads at Gordonvale in Queensland in 1935. They were unsuccessful in controlling Cane Toads - the cane beetles. An Unnatural History Biological control = (1987) Introduction of predators to control a prey species Invasion and the evolution of speed in toads How do invasives move/spread are a c to Relative distance moved (m) 1,500 Relative leg length (ln mm) 0.20 us- Benjamin L. Phillips 1 , Gregory P. Brown 1 , Jonathan K. 0.15 • 1,000 • 0.10 Webb 1 and Richard Shine 1 sect 500 • • 0.05 he • • • • 0 Nature 439 (2006) 0 • se • • • –0.05 • • • ly –500 • • • • –0.10 Cane toads seem to have honed their dispersal • he –1,000 –0.15 • ability to devastating effect over the generations. –0.16 –0.12 –0.08–0.04 0 0.04 0.08 0 10 20 30 40 50 60 70 Pattern of a “typical” invasion oad Relative leg length (ln mm) Time since colonization (yr) out Cane toads ( Bufo marinus ) are large anurans b d 0.15 60 rst Relative leg length (ln mm) (weighing up to 2 kg) that were introduced to • • Radial increase in range • • • 0.10 • 50 Latent phase (small population size) ith • • • Australia 70 years ago to control insect pests in • • • •• • • • • • •• •• • • 0.05 • • • • • • (km yr � 1 ) 40 ve • • • • • • • • • • • • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • sugar-cane fields. But the result has been • • • • • • • • • • • • • • • • • • • • • • • • •• • • • • • • •• • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ••• •• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •• • • • • • • •• • • • • 0 • • • • • • • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •• • • • • • • • • • • • • • 30 in • • • • • • • • • • • • • •• • • • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •• • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • • • disastrous because the toads are toxic and highly • • • • • • •• • • • • • • •• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ••• • • • • • • •• • • • • • • • • • • • –0.05 • • • • • • • • • • • • • • • • • • • • • • • • • • • • •• • • 20 Rapid population growth and spread at • • • • • • • • • • • • •• • •• •• • • • • • • • • • • •• • • • • • • •• invasive. Here we show that the annual rate of • • • • • • • • • • • an –0.10 • 10 • • • progress of the toad invasion front has increased • • • –0.15 • 0 d) 4 4 4 4 5 about fivefold since the toads first arrived; we 0 200 400 600 800 5 6 7 8 0 – – – – – set 5 5 5 0 1 Order of arrival 4 5 6 8 0 find that toads with longer legs can not only move 9 9 9 0 9 2 1 1 1 1 ht- Period faster and are the first to arrive in new areas, but ive also that those at the front have longer legs than ve Figure 1 | Morphology of cane toads in relation to their speed and invasion toads in older (long-established) populations. The history. a, b, Compared with their shorter-legged conspecifics, cane toads ny disaster looks set to turn into an ecological r 2 � 0.34) ( a ), and with longer hind limbs move further over 3-day periods ( ill nightmare because of the negative effects are in the vanguard of the invasion front (based on order of arrival at the id invasive species can have on native ecosystems 1, study site; r 2 � 0.11) ( b ). c, Cane toads are relatively long-legged in recent r 3 , 2 ; over many generations, rates of invasion will populations, and show a significant decline in relative leg length with time on’ be accelerated owing to rapid adaptive change in in older populations ( r 2 � 0.05). d, The rate at which the toad invasion has ng progressed through tropical Australia has increased substantially since the invader 3 , with continual 'spatial selection' at ds’ toads were first introduced in 1935 ( r 2 � 0.92). the expanding front favouring traits that increase the toads' dispersal 4, 5 . Opuntia Effect of invasive species in South-Africa Predation Reconstructing 50 years of Opuntia stricta invasion in the Kruger National Park, South Africa: environmental determinants and propagule pressure Llewellyn C. Foxcroft, Mathieu Rouget, David M. Richardson and Sandra Mac Fadyen Diversity and Distributions, (2004) 10: 427–437
Introduction The brown tree snake Brown tree snake was first detected on ( Boiga irregularis ) Guam in the 1950s near on Guam the Naval Port (central Guam), but may not have become conspicuous away from the port area until the early 1960s. � By the mid 1960s, the snake had colonized over half of the island. � In 1968, the snake had reached the extreme northern end of the island and was present throughout the island, although its densities varied widely from region to region. Status of forest species on Guam Threat to other species Eradication and Detection Other threats
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