NRM top tips - July: Protect litter and groundcover to reduce erosion and weeds, and provide habitat

Groundcover is any material on or near the soil surface, including living and dead plants, plant litter, bark, leaves, manure and rocks. Most of us are aware of the importance of maintaining groundcover for protecting soils from erosion, moderating soil temperature and capturing rainfall and nutrients which are important for soil and plant health. Less well known is the important role groundcover, in particular surface litter, plays in providing habitat for fauna and sources of propagules (seeds, pores and suckers) for riparian and floodplain vegetation regeneration.

The dead organic material that makes up surface litter provides nesting material, hiding places and habitat for a diversity of organisms such as birds, snakes, lizards, worms, spiders, snails and microscopic decomposers like fungi and bacteria. 

CRDC-funded research undertaken by Dr Sam Capon and Dr Stephen Balcombe (Griffith University) within the northern Murray Darling Basin (MDB), found that surface litter along with canopy cover are key drivers of local vegetation dynamics. Their results suggest that leaf litter cover is likely to be particularly important in shaping patterns of groundcover and woody vegetation regeneration in riparian zones. Litter appears to be particularly significant source for woody species, including eucalypts and inhibits seedling emergence from riparian soil seed banks, which according to their experiments, are dominated by weed species.

So what is ‘good’ groundcover? For fauna it is all about diversity, extent and connectivity. The more diverse the materials are that make up groundcover the greater the number of different species that can utilise that habitat. The greater the extent or area of groundcover, often referred to in grazing systems as groundcover percentage, the higher the abundance of species will be. And well connected areas of good groundcover allow for fauna movement through the landscape which is very important for genetic diversity and climate adaptability.

Management practices can have both negative and positive impacts on groundcover. Griffith University's research in the northern MDB found that grazed riparian zones tended to have lower litter cover and groundcover vegetation (overall and in most plant groups), lower shrub cover, a greater proportion of bare ground and are ‘shrubbier’ with respect to trees (i.e. higher stem density and lower tree basal area) than ungrazed sites. Limiting grazing in riparian areas will not only benefit groundcover habitat users, but potential also terrestrial and aquatic fauna species that rely on woody vegetation as habitat and food sources.