Victorian Alpine Plot Network (ATEX): Plot Microclimate Data, Bogong High Plains, Victoria, Australia, 2014–2015

Abstract: The objective of the Australian Tundra Experiment(ATEX) is to assess the likely response of vegetation and invertebrates to temperature increases attained through passive warming.

The Australian Tundra Experiment (ATEX) follows the International Tundra Experiment (ITEX) protocol (Molau & Mølgaard 1996, Jarrad et al. 2009) which focuses on the growth and phenological responses of cold adapted vascular plant species to environmental change, specifically, to an increase in summer (growing season) temperatures. In addition to monitoring vegetation responses, the experimental warming chambers were used to monitor the response of invertebrates to warming. Warming is achieved using hexagonal fibreglass open-top warming chambers (OTCs).

The OTCs were set up in December 2003 at 4 sites within a 2 × 4.5 km area of the Bogong High Plains, Victoria, Australia, known as Rocky Knobs (36.90ºS, 147.27ºE). Two of the sites were established on vegetation that had been recently burnt by the 2003 bushfires. The sites are at approximately 1700 m above sea level and generally have snow cover of variable depth for 3 to 4 months each year (June-July to September-October).

At each site, permanent plots of 1 m2 were selected to include as many of the common vascular grassland species as possible. Treatments were then allocated at random for a total of 40 control and 40 warmed plots. This dataset contains microclimate data for a subset of plots from 30-05-2014 to 2-05-2015.

Sampling method: Each data logger used four sensors: ambient temperatures at 5 cm above the ground surface, soil surface temperatures, and soil temperatures 5 cm and 10 cm below ground. The soil surface sensor was positioned in an inter-tussock gap. Temperatures were recorded hourly.

On 24/10/2008, due to problems with loggers, we replaced all Hobo H8 Outdoor/Industrial 4-channel loggers with a reduced set of HOBO U12 4-Channel External Data loggers (U12-008). Because analyses of the data showed that temperatures at the two unburnt sites were similar, as were temperatures at the two burnt sites, the new loggers were put in only at ITEX1U and ITEX3B.

Study extent: At the beginning of the experiment in 2004, 24 Hobo H8 Outdoor/Industrial 4-channel data loggers were set up next to 24 plots across the 4 Australian ITEX sites. ITEX1U and ITEX2U (the two unburnt sites) each had 8 loggers: half randomly assigned to control (un-warmed) plots and half randomly assigned to OTC (warmed) plots.

The two burnt sites (ITEX3B and ITEX4B) also had loggers, but because these sites had fewer plots and because of financial constraints only 4 loggers per site were installed (2 controls and 2 OTCs per site).

Project funding: The experiment was initiated with funds from an Australia Research Council Linkage Grant for the period 2003-2006. A second Linkage Grant provided funds to continue the project from 2008 to 2012. Between 2012 and 2018 this project was part of, and funded through the Long Term Ecological Research Network (LTERN) a facility within the Terrestrial Ecosystem Research Network (TERN) and supported by the Australian Government through the National Collaborative Research Infrastructure Strategy.

摘要：澳大利亚苔原实验（Australian Tundra Experiment, ATEX）的研究目标是评估植被与无脊椎动物对被动增温引发的气温升高的潜在响应。
本实验遵循国际苔原实验（International Tundra Experiment, ITEX）的试验规程（Molau与Mølgaard，1996；Jarrad等，2009），核心研究冷适应维管植物物种对环境变化（尤其是夏季（生长季）气温升高）的生长与物候响应。除监测植被响应外，实验增温舱还被用于观测无脊椎动物对增温的响应。增温通过六边形玻璃纤维开放式顶部增温舱（open-top warming chambers, OTCs）实现。
OTCs于2003年12月在澳大利亚维多利亚州博贡高平原一片2×4.5km范围内的洛基诺布斯（坐标36.90°S，147.27°E）区域内的4个样地中搭建完成。其中2个样地的植被曾受2003年丛林大火影响而近期被烧毁。所有样地海拔约1700米，每年通常有3至4个月（6-7月至9-10月）存在不同厚度的积雪覆盖。
每个样地中均选取面积为1平方米的永久样方，尽可能纳入更多常见的草原维管植物物种。随后随机分配处理组，共设置40个对照组样方与40个增温处理样方。本数据集包含2014年5月30日至2015年5月2日期间部分样方的微气候数据。

采样方法：每台数据记录仪配备4个传感器，分别用于监测地表以上5厘米处的气温、地表温度以及地下5厘米和10厘米处的土壤温度。地表温度传感器安装在草丛间隙中。温度数据按小时记录。
2008年10月24日，由于原有记录仪出现故障，我们将所有Hobo H8户外/工业级4通道数据记录仪更换为精简款HOBO U12 4通道外置数据记录仪（U12-008）。经数据分析发现，2个未过火样地的温度数据较为相似，2个过火样地的温度数据亦如此，因此仅在ITEX1U与ITEX3B样地中安装了新型记录仪。

研究范围：实验于2004年启动时，在澳大利亚4个ITEX样地的24个样方旁共安装了24台Hobo H8户外/工业级4通道数据记录仪。ITEX1U与ITEX2U（即2个未过火样地）各配备8台记录仪，其中一半随机分配至对照组（未增温）样方，另一半随机分配至OTC增温处理样方。2个过火样地（ITEX3B与ITEX4B）同样安装了记录仪，但由于该样地的样方数量较少且受经费限制，每个样地仅安装了4台记录仪（每个样地含2个对照组与2个OTC增温处理组样方）。

项目资助：本实验于2003-2006年间启动，资金来源于澳大利亚研究理事会（Australia Research Council, ARC）联动项目拨款。2008-2012年间，第二笔联动项目拨款为实验的持续开展提供了支持。2012至2018年，本项目隶属于陆地生态系统研究网络（Terrestrial Ecosystem Research Network, TERN）旗下的长期生态研究网络（Long Term Ecological Research Network, LTERN），并由澳大利亚政府通过国家协同研究基础设施战略提供资助。