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Annex 3: Detailed methodological information for other sectors

A3.1 The agriculture sector

A3.1.1 Uncertainty of animal population data

Details of the surveys and census are included to provide an understanding of the livestock statistics process and uncertainty values. The information documented is from Statistics New Zealand. Full details of the surveys are available from Statistics New Zealand’s website www.stats.govt.nz/datasets/primary-production/agriculture-production.htm.

Agricultural Production Surveys

The target population for the 2006 Agricultural Production Census was all units that were engaged in agricultural production activity (including livestock, cropping, horticulture and forestry) or that owned land that was intended for agricultural activity during the year ended 30 June 2006. The response rate was 86 per cent. These businesses represent 88 per cent of the total estimated value of agricultural output. Statistics New Zealand imputes using a random ‘hot deck’ procedure for values for farmers and growers who did not return a completed questionnaire. Table A3.1.1 gives the sample errors based on a 95 per cent confidence level for the survey data collected in 2006.

Table A3.1.1 Final sampling error and imputation levels for the 2006 Agricultural Production Survey

Statistic Sample errors at 95% confidence interval (%) Percentage of total estimate imputed

Ewe hogget’s put to ram

4

13

Breeding ewes 2 tooth and over

2

13

Total number of sheep

2

12

Lamb born to ewe hogget’s

5

13

Lambs born to ewes

2

13

Beef cows and heifers (in calf) 2 years and over

3

13

Beef cows and heifers (in calf) 1–2 years

6

12

Total number of beef cattle

2

13

Calves born alive to beef heifers/cows

3

13

Dairy cows and heifers, in milk or calf

3

15

Total number of dairy cattle

3

15

Calves born alive to dairy heifers/cows

4

15

Female deer mated

3

12

Total number of deer

4

12

Fawns born on farm and alive at 4 months

3

12

Area of potatoes harvested

8

4

Area of wheat harvested

19

10

Area of barley harvested

12

10

The 1999 livestock survey

The frame for the 1999 Agricultural Production Survey was based on a national database of farms called AgriBase which is maintained by AgriQuality New Zealand Ltd (formerly Ministry of Agriculture and Forestry Quality Management). A sample survey was conducted to obtain estimates of livestock on farms and area sown in grain and arable crops for the 30 June 1999 year. Questionnaires were sent to approximately 35,000 farms. The overall response rate for the survey was 85.7 per cent. The remaining units were given imputed values based on either previous data or on the mean value of similar farms.

A3.1.2 Key parameters and emission factors used in the agricultural sector

Table A3.1.2.1 Parameter values for agriculture emissions of nitrous oxide

Parameter (Fraction) Fraction of the parameter Source Parameter value

FracBURN

Crop residue burned in fields

Ministry of Agriculture and Forestry (expert opinion)

0.5

FracBURNL

Legume crop residue burned in fields

Ministry of Agriculture and Forestry (expert opinion)

0

FracFUEL

Livestock nitrogen excretion in excrements burned for fuel

Practice does not occur in New Zealand

0

FracGASF

Total synthetic fertiliser emitted as NOx or NH3

IPCC (1996) Reference Manual Table 4.19

0.1

FracGASM

Total nitrogen emitted as NOx or NH3

IPCC (1996) Table 4.19

0.2

FracGRAZ

Livestock nitrogen excreted and deposited onto soil during grazing

See Table 6.3.1

Livestock specific

FracLEACH

Nitrogen input to soils that is lost through leaching and run-off

Thomas et al (2002)

0.07

FracNCRBF

Nitrogen in N-fixing crops

IPCC (1996) Reference Manual Table 4.19

0.03

FracNCR0

Nitrogen in non-N-fixing crops

IPCC (1996) Reference Manual Table 4.19

0.015

FracR

Crop residue removed from the field as crop

IPCC (1996) Reference Manual Table 4.19

0.45

Table A3.1.2.2 Emission factor for agriculture emissions of nitrous oxide

Emission factor Emissions Source  

EF1

Direct emissions from nitrogen input to soil

Kelliher and de Klein (2006)

0.01

EF2

Direct emissions from organic soil mineralisation due to cultivation

IPCC (2000) Table 4.17

8

EF3AL

Direct emissions from waste in the anaerobic lagoons AWMS

IPCC (2000) Table 4.12

0.001

EF3SSD

Direct emissions from waste in the solid waste and drylot AWMS

IPCC (2000) Table 4.12

0.02

EF3PRP

Direct emissions from waste in the pasture range and paddock AWMS

Carran et al (1995); Muller et al 1995; de Klein et al (2003)

0.01

EF3OTHER

Direct emissions from waste in other AWMSs

IPCC (2000) Table 4.

0.005

EF4

Indirect emissions from volatising nitrogen

IPCC (2000) Table 4.18

0.01

EF5

Indirect emissions from leaching nitrogen

IPCC (2000) Table 4.18

0.025

Table A3.1.2.3 Emission factor for Tier 1 enteric fermentation livestock and manure management

Emission factor Emissions Source  

EFGOATS

Enteric fermentation – Goats

NZ specific (see Annex 3.1 of NIR)

9

EFHORSES

Enteric fermentation – Horses

IPCC (2000) Table 4.5

18

EFSWINE

Enteric fermentation – Swine

IPCC (2000) Table 4.5

1.5

MMGOATS

Manure management – Goats

IPCC (2000) Table 4.5

0.18

MMHORSES

Manure management – Horses

IPCC (2000) Table 4.5

2.08

MMSWINE

Manure management – Swine

IPCC (2000) Table 4.5

20

MMPOULTRY

Manure management – Poultry

IPCC (2000) Table 4.5

0.117

A3.2 Additional information for the LULUCF sector: the Land Use and Carbon Analysis System (LUCAS)

A3.2.1 Background

The aim of the Land Use and Carbon Analysis System (LUCAS) project is to develop a robust and comprehensive data gathering, management, analysis and reporting system which is consistent with good practice guidance (IPCC, 2000 and 2003) and designed to:

  • Be appropriate for UNFCCC LULUCF sector reporting.

  • Enable reporting under Article 3.3 of the Kyoto Protocol for the first commitment period.

  • Support and underpin New Zealand climate change policy development through to 2012 and beyond.

A3.2.2 Approach

Data Collection

Data collection is separated into three components; forest related, soil related and land-use mapping. Data collection methodologies have been designed to provide unbiased carbon estimates at the national scale. The methods are supported by relevant scientific research. Analysis of the data will provide nationally applicable values for carbon stock and stock change for each of the five carbon pools. The data collection methodologies and the resulting approach to data analysis are being reviewed to provide transparency and to ensure that the activities within the LUCAS project are widely understood.

Natural forests

Natural forest plots have been established on a systematic 8 km grid across New Zealand. Collection of the data from these plots occurred over a five year period and was completed in early 2007. The analysis of these data is underway, the results of which will determine the carbon-status of these managed forests. The next steps include improving the allometric models and to refine future data collection requirements. This analysis will report the results for each of the four biomass carbon pools.

Planted forests

A planted forest carbon inventory and country-specific parameters are being developed for New Zealand to provide an unbiased estimate with known uncertainty for reporting and accounting purposes. Carbon stock estimates will be derived from plot measurements for the four biomass carbon pools. Most – around 90 per cent – of the planted forests in New Zealand are exotic, primarily Pinus Radiata.

Forests planted after the 1st January, 1990

Change in carbon stocks in forests planted after January 1st 1990 will be determined by measurement of trees within plots established on a 4 km grid across New Zealand. A combination of field measurements and airborne LiDAR (Light Detecting and Ranging) will be used. The field measurement programme is underway and will be completed at the end of 2008. LiDAR data capture is planned for February – April 2008. The LiDAR data will be calibrated against the field measurements. For forest plots that are inaccessible, LiDAR data will be processed to provide the total amount of carbon per plot. The total carbon per plot will be separated into the four biomass carbon pools using a specific carbon allocation model. The measurement process will be repeated at the end of the first commitment period, based on the same set of plots. Where new planting covers a point on the 4 km grid, new plots will be established.

Forests planted before the 31st December, 1989

The LUCAS system will also establish the change in carbon stocks in New Zealand’s forests planted before December 31st 1989. The post January 1st 1990 forests approach will be applied, but it is expected that the measurement plots will be on a coarser grid network. It is expected that plot measurements will only be made in the middle of the commitment period, and make use of models to forward- and back-cast carbon values to cover the five year commitment period.

Soils

Soil carbon changes very slowly in response to land-use changes. A New Zealand-specific soil carbon model will be used within the LUCAS database to model this. Soil data for input to the model have been collected under the natural forests work stream and through a number of related research programmes and a specific soil sampling programme. Collation of these data and initial analysis is scheduled to complete mid 2008. These data will allow estimates of soil carbon for different soil types, climate and land-cover/land-use variables in New Zealand. The soils data will be analysed to identify gaps in its coverage across the country. Where significant gaps exist in important land-use areas, further samples and analysis will be performed.

Land use mapping

The LUCAS system has been designed to achieve the following objectives in relation to land use mapping:

  • Determine changes in land use between 1990 and the start of the first commitment period by providing a New Zealand-wide map of land use at 1990 and at 2008.

  • Determine changes in land use through the first commitment period by providing a New Zealand-wide map of land use at 2012.

  • Determining where forests have been harvested, and where deforestation has occurred.

Land use will be mapped as per the UNFCCC categories, namely forest land, cropland, grassland, wetlands, settlements and other land.

Mapping of land use at 1990 is scheduled to be completed towards the end of 2008. The 1990 mapping uses a combination of Landsat 4 and Landsat 5 as well as some SPOT 2 satellite imagery and aerial photography. To assist in the interpretation of the 1990 imagery, land use at 2000–2001 is being determined first, and used to track land use back to 1990. The 2000–2001 mapping is using Landsat ETM+ imagery and aerial photography.

Mapping of land use at 2008 will use SPOT 5 satellite imagery. This imagery is being captured over the 2006/07 and 2007/08 summers (November to March). Mapping of land use will be concluded during 2009.

The LUCAS project is evaluating the use of medium spatial resolution (250 m) MODIS satellite imagery to identify the location and timing of forest harvesting. The intention is to create cloud-free MODIS images of New Zealand on an annual basis. The actual area of harvesting, and deforestation will be determined from high resolution satellite systems or aerial photography. If MODIS proves unsuitable, New Zealand may use satellite radar to identify the location and timing of forest harvesting.

Central database

A component of the LUCAS project is the development of a database to store and manipulate all data. The database will achieve the following objectives:

  • Provide a transparent system for data and calculations.

  • Provide a single repository for the storing, versioning and validation of plot measurements.

  • Store static land use layers and LUCAS derived polygon layers to determine land use and land-use change area nationally.

  • Calculate carbon stocks per hectare for land uses and soils based on the plot and spatial data collected.

  • Produce the CRF reports for the LULUCF sector and reporting under Article 3.3 of the Kyoto Protocol.

A3.2.3 Statistical design and uncertainty

The statistical methods and assumptions will be independently reviewed to ensure they are consistent with best practice statistical design. Opportunities for ongoing improvement of data collection systems will be sought, while considering the cost-effectiveness of alternatives.

Uncertainty in estimated carbon values will be determined as the data collection, land-use mapping and analysis approaches are developed. The uncertainty information will be used to prioritise future improvements in methodologies and data collection.

A3.2.4 Quality Assurance

A quality assurance framework is being developed for the LUCAS project. Once the framework has been agreed, it will be consistently implemented across all LUCAS activities. This will be consistent with New Zealand’s QAQC plan and IPCC good practice guidance (IPCC, 2000 and 2003).