Allelopathic effects and root distribution of Ceratiola ericoides (Empetraceae) on seven rosemary scrub species

Abstract

We studied the root distribution and the effects of leachates from the dominant shrub in rosemary scrub, Florida rosemary (Ceratiola ericoides), on germination of seven subordinate rosemary scrub species. For rosemary scrub specialists, (Eryngium cuneifolium and Hypericum cumulicola), germination was suppressed by the leaf and litter leachates. For species that are not found exclusively in rosemary scrub (Liatris ohlingerae, Polygonella basiramia, Paronychia chartacea, and Palofoxia feayi) litter and leaf leachate did not suppress germination significantly. Species limited to gaps in rosemary scrub (E. cuneifolium, H. cumulicola, and Lechea deckertii) showed reduced germination from rosemary leachates while species not limited to rosemary-free gaps (L. ohlingerae and P. feayi) were not affected by rosemary leachates. Rosemary root abundance was greatest near shrubs, at a shallow depth, and at sites not recently burned. As rosemary scrub patches age, rosemary roots are more likely to interact with herbaceous species in gaps.

Differential belowground allelopathic effects of leaf and root of Mikania micrantha

“…This is in agreement with previous experiments (Richardson and Williamson 1988;Hunter and Mengers 2002). It is generally considered that the target species have different evolutionary histories than invasive or alien species and therefore different resistance to the allelopathic compounds found in the target species (Qasem 2001;Hunter and Mengers 2002).…”

“…This suggests that attributes of seed germination and seedling growth of the target species are differentially susceptible to aqueous extract of M. micrantha (El-darier and Youssef 2000;Jefferson and Pennacchio 2003). This is in agreement with previous experiments (Richardson and Williamson 1988;Hunter and Mengers 2002). It is generally considered that the target species have different evolutionary histories than invasive or alien species and therefore different resistance to the allelopathic compounds found in the target species (Qasem 2001;Hunter and Mengers 2002).…”

“…However, Wang et al (2004) found that M. micrantha leaf extract showed stronger allelopathic effects than root extract on root lengths of the target species. These different responses of bioassay species to leaf and root extracts might be due to the evolutionary differences in the resistance to allelopathic compounds among the target species as stated above (Qasem 2001; Hunter and Mengers 2002). The difference in allelopathic effects of the leaf and root extracts might result from differences in concentrations of diffusible allelochemicals, varied chemical composition, or differentiated alkalinity (Dorning and Cipollini 2006;Batish et al 2007) between leaf and root extracts.…”

Allelopathic potential of Artemisia frigida and successional changes of plant communities in the northern China steppe

“…The three test species showed different sensitivities to A. frigida extracts and volatiles. This might be because of evolutionary differences among the receptors in their resistance to allelopathic compounds (Hunter and Menges 2002;Wu et al 2009). Plant species in the northern China steppe can be classified according to their palatability for sheep grazing; that is, very preferred, preferred, random-intake, and reluctant-intake (Wang 2000).…”

Allelopathic effects of medicinal plants on germination and seedling growth of some weeds

“…In other words, a harmful or beneficial effect of one plant on another via the production of chemical compounds that it releases into the environment directly or indirectly is nominated allelopathy (Siddiqui et al, 2009). Those allelochemicals which indirectly influence on plants growth inhibit microorganisms' activity such as nitrogen-fixing, nitrifying bacteria and ectomycorrhizae (Hunter and Menges, 2002). Allelopathy is one of the many factors which help a plant to establish in an ecosystem (Moktar Hossain et al, 2012).…”