Nitrogen studies in sub-Antarctic terrestrial environments
Metadata record for data from ASAC Project 1022
See the link below for public details on this project.
---- Public Summary from Project ----
Nitrogen studies in subantarctic terrestrial environments Nitrogen is the most important nutrient that plants take up from the soil. Different forms of soil nitrogen exist and plants differ in their ability to ... access these forms. We are determining the nitrogen sources available to plants in the subantarctic environment including the role of penguin-derived nitrogen, soil micro-fauna and the effect of temperature. By studying the nitrogen sources that are used by subantarctic plants, we will be able to better understand the physiological background of species distributions in the subantarctic environment. This research will further our understanding of plant functioning under extreme environmental conditions and allow us to make predictions about the vulnerability of different species to changes in climatic conditions.
From the abstracts of the referenced papers:
In the beginning
Astronomers appear to have discovered that universes have an ecology and indeed a metabolism and no doubt our universe has a distinctive physiological ecology. The task here, however, is to address the physiological ecology of plants. Traditionally, this has deployed two approaches: the in vivo, in which physiological processes were studies at the whole plant or organ level, in field and laboratory, and the in vitro, in which cellular and subcellular processes were dissected in order to understand the mechanisms underlying physiological responses. Bringing us closer to the astronomy fraternity there is a third approach, the in silico, in which computer simulation and graphic modelling provide tools for the study of past and future plants and processes. This contribution attempts to look back to the past, to the origins of life, in order to understand the selectivity in the use of mineral elements and their roles in extant physiological ecology.
What do we know of the conditions present on early Earth that shaped the origin and evolution of life and determined the selection and roles of the mineral elements that are now essential for plant growth? The emergence of life may have occurred in a fairly short interval, microfossils are reported in 3.5-Gyr rock and there is evidence of biogenic carbon isotope fractionation in 3.8-Gyr rock. The early Earth on which life appeared was very different to the planet we inhabit today. Life originated not in a quiescent, favourable environment but rather a violent, impact-ridden one, characterised by enormous tides, intense volcanic activity and heavy meteoritic bombardment. Current thinking is that this early Earth had an atmosphere rich in carbon dioxide and nitrogen, rather than one of methane and ammonia - conditions rather unfavourable for cooking up prebiotic soups.
(Click for Interactive Map)
Values provided in temporal and spatial coverage are approximate only.
From the methods section of one of the referenced papers:
The mean annual temperature of the island at sea level is 5 degrees C and the daily fluctuation is small, on average 1-1.5 degrees C. Similarly, annual ... temperatures display only small changes with average temperatures of 6 degrees C in summer and 3 degrees C in winter. Annual precipitation (mean 900mm) is distributed evenly throughout the year, such that the vegetation rarely experiences water stress. This climate supports 45 vascular plant species and a substantial bryophyte flora (134 species) but no trees, shrubs or legumes.
Plant communities on Macquarie Island were examined during summer and spring, with collections being made in December 1994, January 1996 and November 1996. To study plant nitrogen sources, plants and soil were surveyed along an altitudinal gradient. Sites were situated along a transect crossing the island diagonally from the northeast coast to high plateau sites near the centre of the island. The transect passed through the slopes of a steep valley through an extensive royal penguin (Eudyptes schlegeli) colony at Nuggets Point with 100,000 breeding pairs, to upland plateau sites (Mt Elder) and to a remote site (Prion Lake) more than 2 km from any large penguin colony. The sites surveyed included lush Poa foliosa tussock grassland, medium altitude short grassland with extensive swards of Agrostis magellanica and sparse upland sites with flowering cushion plants (Azorella macquariensis) and moss cushions. A number of sites influenced by different penguin species, seabirds and marine mammals were also investigated.
PDF copies of two of the referenced publications are available for download from the provided URL.
Data Set Progress
+61 7 3365 2732
+61 7 3365 1699
s.schmidt at botany.uq.edu.au
The University of Queensland
DEPARTMENT OF BOTANY
Province or State:
+61 3 6232 3244
+61 3 6232 3351
dave.connell at aad.gov.au
Australian Antarctic Division
203 Channel Highway
Province or State:
Erskine P.D., Bergstrom D.M., Schmidt S., Stewart G.R., Tweedie C.E., Shaw J.D. (1998) Subantarctic Macquarie Island - a model ecosystem for studying animal-derived nitrogen sources using 15 N natural abundance. Oecologia 117. 187-193
Stewart G.R., Schmidt S. (2000) Evolution and ecology of plant mineral nutrition In: Press M.C., Scholes J.D., Barker M.G. Physiological ... Plant Ecology 91-114
Erskine P.D, Bergstrom D.M., Schmidt S., Stewart G.R., Tweedie C.E, Shaw J.D (1999) Royal Fertilizer at the Polar Front. In: Proceedings from the Ninth ITEX Meeting January 5-9, Arctic Laboratory Report 1. 1. 35
Tweedie C.E., Bergstrom D.M. (1999) How will plants and ecosystems alter with climate change in high southern latitudes? Hollister R.D Plant Response to Climate Change: Interation of ITEX Discoveries. Arctic Ecology Laboratories Report 1. Michigan State University. East Lansing, 69-73
Lee J. (2000) Penguins and plants on Macquarie Island: nitrogen and solute accumulation.
Erskine P.D. (1997) The impact of environmental stress on plant nitrogen utilisation in Australian ecosystems. PhD Thesis, Department of Botany, The University of Queensland 1-138
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