A global review of weeds that can germinate from horse dung

Abstract

Summary To assess the diversity of weed seeds dispersed via horse dung, we reviewed 15 studies on seed germination from horse dung – six from Europe, four from North America, three from Australia and one study each from Africa and Central America. Seed from 249 species from 43 families have been identified germinating from horse dung. Almost two‐thirds of the species were forbs and 33% graminoids, with over half being perennials and 32% annuals. Nearly every species (totalling 99% of those reviewed) is considered a weed somewhere, with 47% recorded as invasive and 19% international environmental weeds. Of the 2739 non‐native plants that are naturalized in Australia, 156 have been shown to germinate from horse dung. This includes 16 of the 429 listed noxious weeds in Australia and two weeds of national significance. Seed from 105 of the 1596 invasive/noxious plant species in North America have also been identified germinating from horse dung. Seed traits including seed size, length, width and mass affect dispersal via horse dung. Habitat disturbance from trampling facilitates germination of seedlings from dung in both natural and experimental studies. Some studies found that plants germinating from dung reach maturity and flower, while others found plants did not survive due to unfavourable growing conditions in the field. The diversity of species with seed that can germinate from horse dung highlights the potential of horses to disperse a range of seed over long distances. Whether such dispersal is beneficial or harmful depends on the plant and the context in which it germinates. To maintain the conservation value of protected areas, it is important to understand and manage the different potential weed dispersal vectors, including horses.

Feral horse impacts on threatened plants and animals in sub‐alpine and montane environments in Victoria, Australia

“…Beever et al . ; Ansong & Pickering ). Common weed species in this region include Ribgrass ( Plantago lanceolate ), White Clover ( Trifolium repens ) and Flatweed ( Hypochoeris radicata ) (Prober & Thiele ; Tolsma & Shannon ) , all of which were recorded in our study sites.…”

Notice of and reasons for the Final Determination

“…Increased inputs of soil phosphorus and nitrogen from concentrated urine and faeces (dung heaps) also changes soil nutrient composition in heavily used habitats. In combination, these activities lead to reductions in vegetation cover, richness and structural complexity (Green and Osborne ; NSW NPWS ; NSW NPWS ; Ansong and Pickering ; Doherty et al . ; OEH ; Robertson et al .…”

Association of Non-native Plant Species With Recreational Roads in a National Park in the Eastern Himalayas, China

“…Examples of intentional introduction are ornamental or vegetable plants in gardens and greening/ amenity planting on recreational roads and ski runs (Wilson 1992;Johnston and Pickering 2001;Hulme 2011). Examples of unintentional introduction include transport of plant parts by vehicles (Lonsdale and Lane 1994;Zwaenepoel et al 2006;von der Lippe and Kowarik 2007; Ansong and Pickering 2013a); on clothes, shoes, or equipment (Clifford 1956;Whinam et al 2005;Mount and Pickering 2009); and in the fur and dung of pack animals (Fischer et al 1996;Campbell and Gibson 2001;Ansong and Pickering 2013b).…”