Multiple Disturbances Accelerate Clonal Growth in a Potentially Monodominant Bamboo

Abstract

Organisms capable of rapid clonal growth sometimes monopolize newly freed space and resources. We hypothesize that sequential disturbances might change short-term clonal demography of these organisms in ways that promote formation of monotypic stands. We examined this hypothesis by studying the clonal response of Arundinaria gigantea (giant cane, a bamboo) to windstorm and fire. We studied giant cane growing in both a large tornado-blowdown gap and under forest canopy, in burned and unburned plots, using a split-block design. We measured density of giant cane ramets (culms) and calculated finite rates of increase (lamda) for populations of ramets over three years. Ramet density nearly doubled in stands subjected to both windstorm and fire; the high ramet densities that resulted could inhibit growth in other plants. In comparison, ramet density increased more slowly after windstorm alone, decreased after fire alone, and remained in stasis in controls. We predict that small, sparse stands of giant cane could spread and amalgamate to form dense, monotypic stands (called "canebrakes") that might influence fire return intervals and act as an alternative state to bottomland forest. Other clonal species may similarly form monotypic stands following successive disturbances via rapid clonal growth.

Niches drive peaked and positive relationships between diversity and disturbance in natural ecosystems

“…0. Demographic rates reflected the fact that recruitment may be relatively high in perennial-dominated systems and that mortality can exceed recruitment (e.g., Capers 2003), leading to long-term declines in population growth with increasing disturbance (Gagnon and Platt 2008). Simulations were run for 1 200 000 time steps, with the community initially saturated with H/S individuals of each species.…”

Effect of Forest fire on the regeneration of a bamboo species (<i>Cephalostachyum pergracile</i> Munro) at a mixed deciduous forest in Mae Klong Watershed Research Station, Thailand

“…Therefore, the thinner and shorter culms at the unprotected site would be enough to receive light without intensive competition for light, while the thicker and taller culms would be required to overcome the competition at the protected site. Gagnon and his colleague also found that a bamboo species, Arundinaria gigantean, produce more thinner and shorter culms after fire disturbance when the bamboo receive enough light compared to the bamboo was under closed canopy in North America, even though the rhizome type of this species was different from ours (Gagnon et al 2007, Gagnon andPlatt 2008).…”

“…Bamboo is a fast-growing plant (Lessard and Chouinard 1980) and often colonizes environments disturbed by human activities, wind (Gagnon et al 2007), flood (Guilherme et al 2004), or fire (Gagnon and Platt 2008, Franklin et al 2009, Gagnon 2009, Zaczek et al 2010. Once a disturbed forest becomes dominated by bamboo, the dense and closed bamboo canopy limits light penetration to the forest floor (Montti et al 2011), suppressing germination, regeneration, recruitment, and survival of tree seedlings and saplings in many regions (Nakashizuka 1988, Marod et al 1999, Griscom and Ashton 2003, Budke et al 2010, Montti et al 2011.…”

“…The stem buds of clonal plants are sometimes stimulated to resprout by fire (Bond andWilgen 1996, Zedler 2007). Therefore, organisms such as bamboos that are capable of rapid clonal growth should have an advantage in post-fire environments because they can quickly monopolize the resulting open space and its resources (Gagnon and Platt 2008). At the same time, however, bamboo is easily destroyed by fire (Giri andShrestha 2000, Murray et al 2013).…”

Effects of climate and forest structure on palms, bromeliads and bamboos in Atlantic Forest fragments of Northeastern Brazil

“…Furthermore, palms are key species in tropical forests because they provide important food resources for several species of mammals and birds (Snow, 1981;Eiserhardt et al, 2011). Large bamboo stands can shape forest structure by competing with herbs and trees, and increasing fuel for wildfires (Gagnon and Platt, 2008). Indeed, bamboos may arrest forest succession by shading and physically damaging the seedlings (Griscom and Ashton, 2003).…”