This research project investigated the potential non-targeted (unintended) effects of the
nitrification inhibitor DiCyanDiamide (DCD) on farmland streams and wetlands. The project
was a collaboration between scientists from the University of Otago (effects on streams) and NIWA (effects on wetlands).

Scientific evidence based on a stream survey and field experiments!

Forests cover about one quarter of the Earth’s land surface area. They play a major
role in the present and projected future carbon budget as they contain about 80% of
all above-ground and 40% of below-ground terrestrial organic carbon. They can
become carbon sources when forests are harvested, degraded or damaged or
carbon sinks when new forests are planted or growth rates are enhanced.

Nothofagus is a dominant or co-dominant tree genus in around 70% of New Zealand’s indigenous forest area, yet shows limited regeneration into grasslands (Wardle 1984; Wiser et al. 2011). A lack of ectomycorrhizal inoculum more than ‘one to two tree heights’ from established trees was invoked by Baylis (1980) to explain the lack of Nothofagus spp. establishment into grasslands.

Note, while this document is marked 'confidential', it has since been approved for public release.

Poplars and willows are expected to continue to be the key tree species used to stabilise soil on pastoral hill country in New Zealand. Pastoral hill country is extensive across most regions of New Zealand, and particularly across regions of the North Island of New Zealand. Pastoral hill country erosion is more severe in the North Island, which tends to experience more intense rain storms. Hence the extensive planting of poplars and willows for hill slope stabilisation is more typical in the North Island than in the South Island.

The implications of changes in albedo on the benefits of New Zealand Pinus radiata forests as carbon sinks were assessed by Landcare Research in collaboration with NIWA and Scion for the Ministry of Agriculture and Forestry in June 2008.

Land-cover change has both direct and indirect consequences for the net energy balance of the earth and through that for global warming. Increased carbon storage resulting from afforestatin of pasture lowers the atmospheric carbon dioxide concentration and thus cools the atmosphere. However, forests are usually darker than pastures which means that they absorb more incoming solar radiation. That increased radiation absorbtion warms thte atmosphere.

An increasing concentration of carbon dioxide (CO2) in the atmosphere is the most predictable of the global changes that will alter the environment for our biological industries. Predicted temperature changes for New Zealand are lower than the global average prediction (Niwa, 2011) but, because atmospheric CO2 is relatively well mixed, the rate of change in CO2 will be the same as experienced across the globe. CO2 is rising because of the burning of previously sequestered fossil fuels and changes in land use, in particular the conversion of old growth forest to cropland. Predicting future CO2 concentrations is important because of the direct impact of atmospheric CO2 concentration on terrestrial ecosystems and because CO2 is the most abundant anthropogenic greenhouse gas and thus directly influences potential changes in climate.

Radiata pine comprises approximately 90% of NZ’s exotic plantation forest estate
area and Douglas-fir comprises 5%, with minor contributions from a range of other
species including eucalypts (NEFD 2008). The Forest Carbon Predictor (FCP) was
developed to predict carbon stocks in radiata pine stands, based on comprehensive
biomass data from a range of tree ages, sites, and silvicultural regimes. Biomass
data for species other than radiata pine are limited to a few studies per species.
Carbon stock estimates obtained using the radiata pine model will therefore be
applied to other species, although it is acknowledged that species differences may
exist. To improve the accuracy of carbon stock estimates for Douglas-fir all available
biomass data for this species were used to develop adjustment functions for use with
the FCP version 4.04.

This report has been prepared for the Ministry for Agriculture and Forestry (MAF), as part of
contract CC MAF POL_2008-12 (105-1).

Rainfall deficits are a common feature of New Zealand’s climatic environment and it is not unusual to experience short duration dry spells as isolated regional level events.
Geographically widespread rainfall deficits with durations over one to two months are less frequent, and are usually considered to be ‘agricultural droughts’ as modern pastoral and crop production systems are vulnerable to rainfall deficits of this scale and duration. Recently the widespread rainfall deficit spanning late 2007 to the end of autumn 2008 was estimated to cost the New Zealand economy around $2.8 billion (MAF 2009), mainly from negative on-farm impacts but also from smaller but detectable negative impacts on regional economies.

This document reports on completed and on-going work that examines nitrous oxide emissions from the Waikato River and assesses the results in comparison to previous New Zealand emission factors for indirect losses from rivers. The IPCC’s default emission factor EF5-r currently has a value of 0.0025 kg N2O-N per kg N in the 2006 guidelines1.

MPI Technical Paper No: 2012/38

The objective of this research was to develop a ceonceptual framework for the assessment of the effects of climate chagne on hudrological systems in New Zealand. This research commenced with a literature review emphasizing the types of impacts that have been detected previously and methods for detecting and modelling impacts. The conceptual framework was developed and then applied to the Waimea Pains as a test catchment to assess the effect of climate change. Existing climage and hydrological data were analysed to assess possible climate effects. Hydrological and socioeconomic models were developed and implemented to relate possible climate change to derived changes in water availability and economic productivity within the test catchment

A case study for the Uawa (East Cape) and Waihou (Northland) catchments