Linking Restoration and Ecological Succession (Springer ... - Inecol

60 David A. Wardle and Duane A. Peltzer
Table 3.2 Summary of some roles that soil biota play in three phases of plant invasion: naturalization,
spread, and impact. These examples illustrate that strong links between aboveground and
belowground communities can occur throughout the invasion process.
Phase of invasion Published roles of soil biota
(1) Naturalization Mycorrhizal fungi promote the establishment of an invader (Stampe and Daehler 2003).
Soil biota have negative impacts in a species home range but not its introduced range
(Callaway et al. 2004a and b, Reinhart et al. 2003).
Different N fixing bacterial species are found in the root nodules of invasive plants
compared to native plants (Weir et al. 2004).
Soil pathogenic fungi or nematodes may determine successful establishment of plants
(Knevel et al. 2004, Reinhart et al. 2003, Mitchell and Power 2003, van der Putten 2005).
(2) Spread Mycorrhizal fungi promote the ongoing establishment of an invader (Stampe and Daehler
2003, Wolfe and Klironomos 2005) or control a plant’s abundance within a community
(Klironomos 2002).
Soil pathogenic fungi or nematodes may determine successful spread of naturalized plants
(Reinhart et al. 2003, van der Putten 2005).
Feedbacks between the soil biota and an invasive plant may either promote or slow weed
spread (Packer and Clay 2004).
(3) Impact Mycorrhizal fungi can drive the impacts of an invader on aboveground biota (Wolfe and
Klironomos 2005). For example, the weedy herb Centaurea maculosa can garner P from
neighboring plants via mycorrhizal hyphae (Zabinski et al. 2002).
Invasive plants can produce belowground allelochemicals that suppress native plants (Bais
et al. 2003).
High growth rates or litter quality of the invader causes increases in the soil microbial
biomass and shifts in the soil biota resulting in enhanced nutrient availability (e.g.,
Belnap et al. 2005, Herman and Firestone 2005, Lindsay and French 2005).
Feedbacks between the soil biota and an invasive plant may result in system-level shifts or
crossing of an ecosystem threshold (Wardle 2002, Suding et al. 2004).
restoration efforts. The most common restoration technique involves carbon
addition treatments but it has variable success and no clear links to the role
of soil communities in the success or impact of invaders. There is tremendous
scope in restoration for linking how invaders alter soil communities or processes
to the long-term implications of invasions for vegetation succession and
ecosystem processes. An emerging theme from current literature is that plants
can influence soil communities that in turn regulate plant community composition
or ecosystem processes. Clearly the role of belowground communities
in influencing the spread and impacts of invasive plant species has important
implications for succession and restoration that are only just beginning to be
recognized. This area will provide a fertile arena for research in the coming
decades.
3.6 Conclusions and Future Challenges
An emerging theme in the ecological literature over the past decade is that
aboveground–belowground linkages can drive community composition, successional
processes, and ecosystem development. Each of these processes is
essentially a time-dependent outcome of these linkages, i.e., community composition
shifts most rapidly, succession more slowly, and ecosystem development
slowest of all. This conceptual model is highly relevant for ecosystem