Cogongrass Invasion and Sandhill Resilience I examined invasion of an Asian grass, Imperata cylindrica cogongrass , in sandhill ecosystems in the state of Florida in southeastern North America. Seed were inserted just below the soil surface using long forceps, with minimum disturbance of the litter layer. In addition, this clone produces large amounts viable seed that are dispersed within 10 m of the inflorescence, resulting in 1 new infestation 0. Skip to main content. Some notes on the natural enemies of Alang-alang Imperata cylindrica L. Background of the Study According to survey, from the national solid waste management commission, there are open dump sites, controlled dumps, 21 landfills. Of the pathogens detected in the United States, at least 11 fungal isolates collected from cogon and other grassy weeds in Florida have been tested for their pathogenicity to I.

First I measured rates of vegetative spread invasion of cogongrass, as influenced by various sandhill management practices. Fire intensity values were consistent with published values for similar grassland ecosystems worldwide Frost and Robertson Also, gopher tortoises require open areas for incubation of eggs, with female tortoises excavating nests in bare spots, usually in the apron outside their burrow Cox et al. Method of determining operating capacity Operating capacity will be determined by considering the amount of starch that will be fed in the machine. Cogongrass is one of the 17 most troublesome invasive plants worldwide Holm et al. It is likely that fungi associated with cogon grass are more diverse and abundant than indicated by herbarium records Evans, ; Charudattan, ; Minno and Minno,

Evanssuggested that some of the known pathogens of cogon grass should be considered for introduction to the United States as classical biological control agents. First, I will review the importance of grass invasion worldwide. Since European settlement many 52 pine forests in the Southeast have been burned in the dormant season for silvicultural reasons and for game management MyersRobbins and Myers Although ecosystems prone to frequent fire vary greatly, they are all characterized by periodic drought, frequent sources of ignition such as lightning, and nutrient-limited soils.

Further development of these two fungi as bioherbicides is continuing, but neither fungus is host specific.


Some affect biotic processes, displacing indigenous species, altering species diversity cogoon dominance including keystone species complexesand changing productivity, decomposition, and nutrient cycling. Ecological resilience of an ecosystem is greater when there is a diversity of driver species within each functional group.

cogon grass thesis

To minimize this ecological problem, the use of recyclable resources is one rational solution. During the course of this study the National Forest bought the property and burned the site for the first time in 15 yr.

Gabel identified 29 synonyms for I. Mounds were less numerous in sandhill with dense rather than sparse grass cover, thought by the authors to be due to obstruction of the beetles’ flying and scavenging activities.

Habitat requirements for gopher tortoises, however, may not be met in dense cogongrass. Research Hypotheses In summary, this study was designed to examine the ecological consequences of cogongrass invasion in Florida sandhill ecosystems.

cogon grass thesis

After germination longleaf pines exist for 3 to 5 years in a “grass stage” during which the belowground apical meristemn is protected from low intensity fires.

Seed viability is highest for seeds less than three months old Shilling et al.


Spikelets are 3 to 6 cm long, crowded and paired on unequal stalks, with each spikelet surrounded by white hairs up to 1. While long-distance dispersal of cogongrass in the Grwss is primarily due to inadvertent rhizome transport, seed can contribute to local spread Wilcut et al. Recent burning in both firemanaged and formerly cogom sandhill tended to increase mean rates of spread, although not significantly.

Seedling survival depended strongly on water availability, while growth depended on both water and nutrients.

Should this cold-tolerant cultivar be introduced into the southeast and hybridize with I. I hypothesized that as cogongrass cover increases, cover of sandhill vegetation decreases, and that herbaceous sandhill vegetation is displaced before woody species, while large trees are not affected. More than million ha of cogon grass have been estimated to occur worldwide Holm et al.

Considerable scope exists for additional field surveys, given that I.


cogon grass thesis

Others have been shown to change abiotic processes such as hydrology, soil chemistry, geomorphology, and disturbance regimes. Dalea was planted in only 5 replicates in 2 treatments unburned cogongrass and unburned sandhill because of small numbers of available seedlings.

Chapter 28 Cogon Grass – Biological Control of Invasive Plants in the Eastern United States

Global Grass Invasions Numerous grass species have been carried around the world as forage crops or for soil erosion control Hartley and Williamsand many of the traits that agronomists have traditionally used to select promising forages also identify “ideal weeds” Baker May 15 to Nov.

Three common fossorial animals in southeastern sandhill, Gopheruspolyphemus gopher tortoiseGeomyspinetus southeastern pocket gopherand geotrupine scarab beetles such as Peltotrupesyoungi, burrow to different depths: In this study, this pertains to the product that will be produced by the cutting machine. Season of burning, the last parameter of fire regime, is determined by availability of ignition sources and seasonal variation in fuel moisture and quantity.

The life cycle of O. Since tortoise mounds are sites for seedling establishment and provide refuge from high fire temperatures for seedlings and young plants, the absence of tortoise mounds could affect plant community composition over time.

After the fires, melted paint spots were recorded for each strip.

Ecological consequences of Imperata cylindrica (cogongrass) invasion in Florida sandhill

This Asian pine exists for several years in a grass stage that is resistant to drought and fire, again like longleaf pine.

Cheatgrass increased the size and frequency of fires, 50 leading to increased flooding and erosion, and displacement of shrubs and indigenous grasses Klenunendson and Smith In both sandhill and cogongrass, the bulk of fine thesjs is below 0.

In addition to burrowing animals, a number of threatened or endangered vertebrate animals live in sandhill: