6  Biota

Modified

March 3, 2026

Soil biota both affects and is affected by soil type. For example, Kauri trees create acidic conditions around their root zone, leading to the development of podzolic features.

6.1 Vegetation

Recording vegetation during soil survey can reveal relationships between soil and vegetation community composition and structure.

Three options are available in New Zealand for recording vegetation data in a soils context.

  1. RECCE Standard (Hurst et al. 2022): Use for detailed vegetation assessment. This is the method used by the NZ National Vegetation Survey, and it allows creation of a complete record of vegetation structure and species assemblage. Some elements of the RECCE standard have been adopted elsewhere in this manual, where relevant to describing the landscape and land surface (Section 3.4, Section 10.3). Note: considerable botanical experience is needed to apply the full RECCE standard correctly.
  2. LUC vegetation (Lynn et al. 2009, Appendix 3): Use when soil description is undertaken as part of a Land Use Capability (LUC) assessment, and for routine vegetation assessment during other soil description activities. This system describes a set of 49 vegetation communities commonly found in New Zealand, grouped into five broad structural categories (grasses, crops, scrub, forest, and herbaceous). Ability to identify key local species will be required to apply the system correctly. The system should also be used for routine vegetation assessment during other soil mapping activities.
  3. NZLRI land cover (Section 7.1): Use for very rapid assessment. This system will convey both land cover and basic vegetation information.

Simpler systems that attempt to break vegetation communities into key structural classes are available in New Zealand, including local classifications and the ‘Atkinson system’ recommended in the previous version of this manual. These are easy to apply but may not adequately discriminate between vegetation communities in a way that is soils-relevant.

Note that vegetation condition assessment is beyond the scope of this document.

6.2 Soil Fauna

Soil fauna play a critical role in organic matter breakdown, soil nutrient and water cycling, and profile development.

6.2.1 Megafauna

Soil megafauna are large species that may not be directly dependant on the soil for any part of their life cycle, but still significantly and directly affect the soil, usually by mechanical disturbance or organic material addition. In New Zealand this role was largely filled by birds and reptiles before the arrival of humans. Since then, the niche has been dominated by introduced mammals. Significant increases in the volume of animal wastes added to many soils have also occurred, most intensely on land converted to pastoral agriculture.

The influence of these animals is generally captured elsewhere in a soil description (e.g. Section 10.4) and so no further morphology recording requirements are defined in this handbook.

6.2.2 Macrofauna

Macrofauna are those soil-dwelling animals with a body width of ~2–20 mm. The influence of these animals is generally captured in a soil description as infill features (Section 11.5) or voids (Section 12.4.1), as well as cast structures (Section 12.1.3) . In New Zealand, soil bioturbation by native macrofauna has been considered to be relatively low, excepting some endemic earthworms and dung beetles. Introduced earthworms and beetles have had a substantial impact on topsoils under pasture.

6.2.3 Meso- and Microfauna

The soil meso- and microfauna are much smaller, with body widths of 0.1–2.0 mm and <0.1 mm respectively. They live mostly within soil pores and in the soil solution. Mesofauna like mites and collembolans can contribute a great deal to soil porosity and air content. Microfauna like nematodes and bacteria are less able to influence the soil structure directly, although some generate soil-aggregating substances. No observational requirements are defined for meso- or microfauna in this handbook.

6.3 Ecosystems

A variety of ecosystem classifications are available for parts of the New Zealand landscape (Johnson and Gerbeaux 2004; Wiser et al. 2011), as well as for the country as a whole (Leathwick et al. 2003; Singers and Rogers 2014). These may be of interest in specific circumstances but no recording requirements are defined in this handbook.