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New Zealand and Chile share a number of ecological and climatic factors, including latitudes, mountainous landscapes, soils originating from volcanic ash, and similar lithology, climate, and isolation (Challies & Murray, 2006). Geographic location and associated features mean that both countries benefit from a complete set of natural barriers. While New Zealand is a group of islands in Oceania in the South Pacific Ocean, Chile is located in Southwest South America, with the Pacific Ocean coastline stretching more than 4,300 kilometres long to the west; the Andes7 to the east; the Atacama which is the world’s most arid desert to the North; and the Antarctic to the south. Due to the geographic isolation, strict border controls, and similar farming practices, both countries are free from a range of diseases that are endemic in the rest of the world.

The variability in the New Zealand climate is due to its turbulent mid-latitude location, which is influenced by many features from the Tropics to the sub-Antarctic (National Institute for Water and Atmospheric Research [NIWA], 2010). Much of the variability in the New Zealand climate originates from the interactions of global air circulation and orography being the west to east gradient in rainfall the most notable effect. Evenly distributed, frequent damaging events can include floods, droughts, wind storms, and heat waves (NIWA, 2010).

7 _{The Andes is the longest continental mountain range in the world, being a continuous range of}

highlands along the western coast of South America. This range is about 7,000 km long, about 200 km to 700 km wide, with an average height of about 4,000 metres.

Chile extends between 22 and 55 degrees of latitude South, with strong climatic influences form the sea and the Andes. A large area has a mountain climate with perpetual snow and glaciers. However, a large percentage of the population lives where agriculture thrives in the lowlands of Central and Southern Chile. This part of Chile tends to be wet all year round, with changeable weather (Escobar et al., 2006). Annual precipitation can be as high as 5,000 mm (200"), much of which falls as snow farther south and on the higher mountains. On the coast, winters are rarely extremely cold, but summers are cool and cloudy. Figure 4 shows the countries, their latitudes, with their key dairy farming regions highlighted in darker shading.

Figure 4. New Zealand and Chile dairy regions and latitudes. Adapted from: Challies & Murray (2006)

In New Zealand, grassland occupies approximately 45% of the country’s area and can be grown and intensively grazed all year round (McCall & Clark, 1999). However, NZ grasslands still

show large variation in land characteristics, winter temperatures, and summer soil moisture (Hodgson, 1999; Holmes, 2003). In the majority of the New Zealand’s non-mountainous territory the climate is temperate. Mean daily temperatures range from 8°C in July to 17°C in January, but summer temperatures can reach over 30°C in many places (NIWA, 2011). The average rainfall ranges widely from less than 400 mm in the Central South Island (Otago) to around 1,000mm in most regions (Gaul & Hughes, 1996). For the majority of the North Island and northern South Island, the driest season is summer (December–February), but for much of the South Island, winter (June–August) is the driest season.

Over the period 2006 to 2011, NIWA reported that there were several extreme events. The 2006/07 was a good climatic year, but the 2007/08 summer was the driest in a century in parts of the North Island, particularly in the Waikato region and the eastern South Island (Dairy NZ, 2009). Pasture growth, pasture covers, milk production, and stock body condition were severely affected by the drought. Dairy NZ (2010) indicated that the 2008/09 season was fairly typical climatically in most regions, but dry weather was again a factor in some major dairying regions, such as the Waikato and Bay of Plenty, and also in the Auckland region, Northland, central North Island, and the north and east of the South Island. In contrast, it was a wet year in Gisborne, Manawatu, and parts of Westland. A Dairy NZ economic survey (2011), reported that 2009/10 was a difficult climatic year for most regions, mainly due to a late summer/autumn drought affecting most of the upper North Island and some parts of the South Island. These widespread autumn droughts resulted in early drying-off of dairy herds in many regions, although the effects of the drought were less severe in the South Island as many Canterbury farms irrigated their pastures and parts of Otago–Southland had 42% more rainfall than average in early 2010.

The Chilean southern plains and their temperate grasslands extend south from 38º Latitude S up to approximately 44º S. Mean monthly temperatures range between 5 ºC in the winter months and 12-15 ºC in summer (Vera, 1996). Rainfall increases in the north to south direction from about 1,400 mm to over 2,000 mm, with 70% of the rain concentrated from early autumn to early spring (Balocchi & Lopez, 2001). Summer rainfall represents between 10 to 17% of this total in the north and south, respectively. This wheather pattern creates a brief water deficit during peak summer in the northern part of the region, which does not exist at the southern end. Over the period 2007 to 2011, according to the Dirección Meteorologica of Chile (2007, 2008, 2009, 2010 and 2011), rainfall patterns were varied. In 2007, key dairying regions such as Valdivia and Osorno were drier than normal (about 1,200 mm of rain in Valdivia and just less than 900 mm in Osorno). In 2008, rainfall was 1,995 mm and 1,028 mm respectively, while in 2009, Valdivia had 1,950 mm and Osorno a maximum of 1,345 mm. In 2010, Valdivia had an

annual rainfall closer to average of 1,491 mm and Osorno also totalled 1,041 mm, similar to those observed in 2011: 1,618 mm and 995 mm respectively.