Parasites boost productivity: effects of mistletoe on litterfall dynamics in a temperate Australian forest

Abstract

The importance of litter in regulating ecosystem processes has long been recognised, with a growing appreciation of the differential contribution of various functional plant groups. Despite the ubiquity of mistletoes in terrestrial ecosystems and their prominence in ecological studies, they are one group that have been overlooked in litter research. This study evaluated the litter contribution from a hemiparasitic mistletoe, Amyema miquelii (Lehm. ex Miq.) Tiegh., in an open eucalypt forest (Eucalyptus blakelyi, E. dwyeri and E. dealbata), at three scales; the forest stand, single trees and individual mistletoes. Litter from mistletoes significantly increased overall litterfall by up to 189%, the amount of mistletoe litter being proportional to the mistletoe biomass in the canopy. The high litter input was due to a much higher rate of mistletoe leaf turnover than that of host trees; the host litterfall and rate of leaf turnover was not significantly affected by mistletoe presence. The additional litter from mistletoes also affected the spatial and temporal distribution of litterfall due to the patchy distribution of mistletoes and their prolonged period of high litterfall. Associated with these changes in litterfall was an increase in ground litter mass and plant productivity, which reflects similar findings with root-parasitic plants. These findings represent novel mechanisms underlying the role of mistletoes as keystone resources and provide further evidence of the importance of parasites in affecting trophic dynamics.

Native Cuscuta campestris restrains exotic Mikania micrantha and enhances soil resources beneficial to natives in the invaded communities

“…Mikania micrantha (Compositae, hereafter referred to as Mikania) is among the 100 most notorious invaders in the world (Lowe et al 2001). Since its first reported occurrence in the early 1980s, Mikania has invaded a broad range of habitats in southern China, resulting in tremendous economic and environmental losses (Li et al 2000Wang et al 2004;Zhang et al 2004).…”

Mistletoes: Pathology, Systematics, Ecology, and Management

“…Aside from the well studied one-way flow of water, nutrients, and a variable proportion of photosynthate from host to parasite, recent work has documented the ability of mistletoes to return a range of nutrients back to the host and surrounding organisms via litter-fall (128). As with several root parasites, mistletoe litter contains high proportions of many elements, especially P and K. Coupled with the high turnover of mistletoe leaves, this leads to substantial nutrient enrichment beneath mistletoe plants, altering rates of decomposition and affecting growth rates of annual plants (128). To date, mistletoe litter-fall has been studied only in eucalypt woodlands, characterized by skeletal soils and very low baseline amounts of phosphorous.…”

Ecology of neotropical mistletoes: an important canopy-dwelling component of Brazilian ecosystems

“…Recently, a new avenue of research found the role of mistletoes in nutrient cycling in ecosystems (March & Watson 2007;. Mistletoes can alter the spatial and temporal distribution of nutrient cycling and enhance the quantity of nutrients available to hosts.…”

“…Th e second explores the role of mistletoes as a food resource for groups of organisms, including pollinators (e.g., Barros et al 2001;Azpeitia & Lara 2006), seed dispersers (e.g., López de Buen & Ornelas 1999;Carlo & Aukema 2005) and herbivores (e.g., Guerra et al in press). Th e last approach is directed towards understanding interactions between mistletoes and their environment, which seeks to determine the infl uence of mistletoes on the composition of plants and animals via their modifi cation of vertical and horizontal vegetation structures, water uptake and plant succession (March & Watson 2007;.…”