303,135 research outputs found
Fourteen degrees of latitude and a continent apart: comparison of lichen activity over two years at continental and maritime Antarctic sites
There are marked declines in precipitation, mean temperatures and the number of lichen species with increasing latitude in Antarctica. However, it is not known which factors are the predominant controllers of biodiversity changes. Results are presented from over two years of almost continuous monitoring of both microclimate and activity in lichens at Livingston Island, South Shetland Islands, 62°S, and Botany Bay, Ross Sea region, 77°S. Lichen activity was evident over a much longer period at Livingston Island, (3694 versus 897 hours) and could occur in any month whereas it was almost completely confined to the period November–February at Botany Bay. Mean air temperatures were much lower at Botany Bay (-18° compared to -1.5°C at Livingston Island), but the temperatures at which the lichens were active were almost identical at around 2°C at both sites. When the lichens were active incident light at Botany Bay was very much higher. The differences are related to the availability of meltwater which only occurs at times of high light and warm temperatures at Botany Bay. Temperature as a direct effect does not seem to explain the differences in biodiversity between the sites, but an indirect effect through active hours is much more probable. In addition there are negative effects of stresses such as high light and extreme winter cold at Botany Bay
Cypripedium acaule Aiton
https://thekeep.eiu.edu/herbarium_specimens_byname/21429/thumbnail.jp
Spiranthes cernua (L.) Rich.
https://thekeep.eiu.edu/herbarium_specimens_byname/21418/thumbnail.jp
Spiranthes cernua (L.) Rich.
https://thekeep.eiu.edu/herbarium_specimens_byname/21418/thumbnail.jp
Cypripedium acaule Aiton
https://thekeep.eiu.edu/herbarium_specimens_byname/21428/thumbnail.jp
Gene flow risk assessment in centres of crop origin and diversity
Poster presented at Plant Biology & Botany Join Congress. Chicago (USA), 7-11 Jul 200
Aquatic Vegetation Inventory and Mapping at Promised Land State Park
This project was undertaken, primarily, to improve our understanding of the aquatic vegetation of the lakes at Promised Land State Park. Both Promised Land Lake and Lower Lake are home to substantial diversity of aquatic plant species, but vary in physical structure, species assemblages, and specific plant community composition.
Multiple methodologies were used to survey for species presence and attempt to characterize communities.
It is well understood that the Bureau of State Parks is under pressure from competing interests to manage its aquatic resources for purposes ranging from biological conservation to various forms of active recreation. These interests are often at odds and irreconcilable, particularly in the context of aquatic ecosystems.
In both cases, Promised Land Lake and Lower Lake, we advise that no effort be undertaken to actively manage aquatic vegetation, in spite of the presence of large populations of Myriophyllum heterophyllum, an aggressive weed, in both lakes.
We further suggest that additional resources be dedicated to continuing examination of aquatic resources at Promised Land State Park. This baseline study represents an opportunity to build a thorough scientific study over time
Cypripedium acaule Aiton
https://thekeep.eiu.edu/herbarium_specimens_byname/21428/thumbnail.jp
Backdrop to encounter : the 1770 landscape of Botany Bay, the plants collected by Banks and Solander and rehabilitation of natural vegetation at Kurnell
The first scientific observations on the flora of eastern Australia were made at Botany Bay in April–May 1770. We discuss the landscapes of Botany Bay and particularly of the historic landing place at Kurnell (lat 34˚ 00’ S, long 151˚ 13’ E) (about 16 km south of central Sydney), as described in the journals of Lieutenant James Cook and Joseph Banks on the Endeavour voyage in 1770. We list 132 plant species that were collected at Botany Bay by Banks and Daniel Solander, the first scientific collections of Australian flora. The list is based on a critical assessment of unpublished lists compiled by authors who had access to the collection of the British Museum (now Natural History Museum), together with species from material at National Herbarium of New South Wales that has not been previously available. The list includes Bidens pilosa which has been previously regarded as an introduced species. In 1770 the Europeans set foot on Aboriginal land of the Dharawal people. Since that time the landscape has been altered in response to a succession of different land-uses; farming and grazing, commemorative tree planting, parkland planting, and pleasure ground and tourist visitation. We describe and reconstruct the 1770 vegetation and landscape features of the Kurnell landing place site, now within Botany Bay National Park, based on primary historical sources and surviving remnants of the landscape, and suggest ways in which the remnants can be rehabilitated and enhanced to protect and focus on the botanical, historical and cultural values of this important place
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