Native and no-native plant interactions in Australian grasslands

This dataset contains all data, on which the following publication below is based.
Paper Citation:
_Schlierenzauer, C., Risch, A.C., Schütz, M., Firn, J. 2021. Non-native Eragrostis curvula reduces plant species diversity in pastures of South-eastern Australia even when native Themeda triandra remains co-dominant. Plants 10, 596._
Please cite this paper together with the citation for the datafile.
Study area
The study was conducted in the lowland grassy woodlands of the Bega Valley Region, which is located in the south-east corner of New South Wales, Australia. Embedded between the Pacific Ocean and the Australian Alps, the lowland grassy woodlands are mostly located on granitic substrates and reach elevations of roughly 500 m above sea level. Typically, these grassy woodlands receive less precipitation (mean annual precipitation between 700-1100 mm) compared to the more elevated areas that surround them (NSW Government - Office of Environment and Heritage 2017).
The vegetation is dominated by an open tree canopy layer consisting of Eucalyptus tereticornis Sm, Angophora floribunda Sm. (Sweet) and a range of other eucalypt species. Sometimes shrub or small trees are also present, whereas grasses and forbs form the ground-cover. In areas without intensive agricultural history, this layer is dominated by perennial, tussock grasses such as Themeda triandra Forssk, Microlaena stipoides R.Br (Weeping Grass), Eragrostis leptostachya Steud. (Paddock Lovegrass) and Echinopogon ovatus P.Beauv (Forest Hedgehog Grass). The remaining inter-tussock spaces are occupied by a diversity of growth-restricted grasses and herbaceous forbs (NSW - Department of Planing, Industries and Environment 2019; NSW Government - Office of Environment and Heritage 2017).
Clearing, pasture sowing, fertilizer application and livestock grazing resulted in a dramatic decrease in the extent of these natural woodlands, with less than five percent within conservation reserves and overall, with only about 20% of their original extent in New South Wales still existing (Tozer et al. 2010). The remaining areas outside of reserves are threatened by altered fire frequencies, habitat clearing, livestock grazing and especially by non-native plant invasion, particularly Eragrostis curvula (Schrad.) Nees. For this reason, the grassy woodlands are listed as an endangered ecological community in the NSW state legislation. Additionally, they are considered as critically endangered by the Commonwealth of Australia (Threatened Species Scientific Committee (TSSC) 2013).
Experimental design and sampling
The study was conducted on six farms and in each of them two sites were chosen, representing a paired design. One of the sites at each farm is dominated by native Themeda triandra, the other one co-dominated by non-native Eragrostis curvula and Themeda triandra. All farms are within a radius of approximately 10 km from the town Candelo. Three of the farms are located North (36°40’ to 36°42’ S and 149°38’ to 149°42’ E) and three of them are located South (36°51’ to 36°49’ S and 149°38’ to 149°42’ E) of Candelo.
Non-native herbivores (mainly cattle, sheep and rabbits) and native herbivorous marsupials (mainly kangaroos, wallabies and wombats) are present in the area of these sites. On each site, data was collected within four plots (each 1 x 1 m) in May and November 2020. All plant species found within a plot were recorded and their relative abundance was estimated.
References
NSW - Department of Planing, Industries and Environment. 2019. “Lowland Grassy Woodland in the South East Corner Bioregion - Endangered Ecological Community Listing.” https://www.environment.nsw.gov.au/topics/animals-and-plants/threatened-species/nsw-threatened-species-scientific-committee/determinations/final-determinations/2004-2007/lowland-grassy-woodland-south-east-corner-bioregion-endangered-ecological-community-l (February 18, 2021).
NSW Government - Office of Environment and Heritage. 2017. “Lowland Grassy Woodland in the South East Corner Bioregion - Profile.” https://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=20070 (January 31, 2021).
Threatened Species Scientific Committee (TSSC). 2013. Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) Conservation Advice for Lowland Grassy Woodland in the South East Corner Bioregion. http://www.environment.gov.au/biodiversity/threatened/communities/pubs/82-conservation-advice.pdf.
Tozer, Mark et al. 2010. “Native Vegetation of Southeast NSW: A Revised Classification and Map for the Coast and Eastern Tablelands.” Cunninghamia : a journal of plant ecology for eastern Australia 11(3): 359–406.

本数据集包含支撑下述发表文献的全部相关数据。
论文引用：
Schlierenzauer, C., Risch, A.C., Schütz, M., Firn, J. 2021. 外来弯穗画眉草（Eragrostis curvula）在澳大利亚东南部牧场中降低植物物种多样性，即便本地黄背草（Themeda triandra）仍为共优势种。 *Plants* 10, 596.
请在引用本数据集的同时，一并引用上述论文。

研究区域
本研究在澳大利亚新南威尔士州东南角的贝加谷地区低地草本林地开展。该区域介于太平洋与澳大利亚阿尔卑斯山之间，低地草本林地多分布于花岗岩基质之上，海拔约500米。与周边高海拔区域相比，此类草本林地的年降水量更低，年均降水量介于700~1100毫米之间（新南威尔士州政府环境与遗产办公室，2017）。

植被特征
植被以开阔的乔木层为主体，优势树种包括细叶桉（Eucalyptus tereticornis Sm.）、宽叶桉（Angophora floribunda Sm. (Sweet)）及多种其他桉属物种。区域内偶见灌木或小乔木，草本与非禾本草本植物构成地被层。在未经历高强度农业开发的区域，地被层以多年生丛生禾草为主，包括黄背草（Themeda triandra Forssk.）、垂穗草（Microlaena stipoides R.Br.，英文名Weeping Grass）、细穗画眉草（Eragrostis leptostachya Steud.，英文名Paddock Lovegrass）以及卵果刺芒草（Echinopogon ovatus P.Beauv.，英文名Forest Hedgehog Grass）。剩余的草丛间隙则被多种生长受限的草本与非禾本草本植物占据（新南威尔士州规划与环境产业部，2019；新南威尔士州政府环境与遗产办公室，2017）。

生境退化现状
林地清理、牧场播种、化肥施用与家畜放牧导致此类天然林地的面积大幅缩减：新南威尔士州境内仅存约20%的原始林地面积，其中不足5%位于保护地内（Tozer等，2010）。保护地外的剩余林地面临着火频改变、栖息地清理、家畜放牧，尤其是外来植物入侵的威胁，其中尤以弯穗画眉草（Eragrostis curvula (Schrad.) Nees）为甚。正因如此，此类低地草本林地在新南威尔士州立法中被列为濒危生态群落，同时被澳大利亚联邦政府认定为极危生态群落（受威胁物种科学委员会（TSSC），2013）。

实验设计与采样方案
本研究在6个农场开展，每个农场选取2个样地，采用配对实验设计。每个农场的其中一个样地以本地黄背草（Themeda triandra）为优势种，另一个样地则由外来种弯穗画眉草（Eragrostis curvula）与黄背草共同占据优势。所有农场均位于坎德洛镇周边约10公里半径范围内，其中3个农场位于坎德洛以北（南纬36°40′~36°42′，东经149°38′~149°42′），另外3个位于坎德洛以南（南纬36°49′~36°51′，东经149°38′~149°42′）。样地区域内存在外来草食动物（主要为牛、羊与野兔）与本地有袋类草食动物（主要为袋鼠、沙袋鼠与袋熊）。2020年5月与11月，在每个样地内设置4个1m×1m的样方，记录样方内出现的所有植物物种，并估算其相对多度。

参考文献
1. 新南威尔士州规划与环境产业部. 2019. 《东南角生物区低地草本林地——濒危生态群落名录》. https://www.environment.nsw.gov.au/topics/animals-and-plants/threatened-species/nsw-threatened-species-scientific-committee/determinations/final-determinations/2004-2007/lowland-grassy-woodland-south-east-corner-bioregion-endangered-ecological-community-l（2021年2月18日访问）
2. 新南威尔士州政府环境与遗产办公室. 2017. 《东南角生物区低地草本林地——概况》. https://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=20070（2021年1月31日访问）
3. 受威胁物种科学委员会（TSSC）. 2013. 《1999年环境保护与生物多样性保护法案（EPBC法案）东南角生物区低地草本林地保护建议》. http://www.environment.gov.au/biodiversity/threatened/communities/pubs/82-conservation-advice.pdf
4. Tozer, Mark等. 2010. 《新南威尔士州东南部原生植被：海岸与东部台地的修订分类与地图》. Cunninghamia：澳大利亚东部植物生态学期刊 11(3): 359–406.