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18 - Signs of Climate Change in the Bryoflora of Hungary
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- By Tamás Pócs, Eszterházy College
- Edited by Zoltán Tuba, Nancy G. Slack, Sage Colleges, New York, Lloyd R. Stark, University of Nevada, Las Vegas
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- Book:
- Bryophyte Ecology and Climate Change
- Published online:
- 05 October 2012
- Print publication:
- 06 January 2011, pp 359-370
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Summary
Introduction
As the average shift of isotherms in Central Europe has been some 200 km northeastwards during the past 60 years, we might expect changes in the flora of Hungary, especially among the cryptogams, owing to their superior dispersal ability by spores and gemmae. During the past 50 years of global warming in Central Europe the average temperature rose by 0.8 °C, which alone does not mean as much as the increasing extremes both in temperature and in the annual distribution of precipitation. In Hungary 1990 was probably the hottest year of the millennium, followed by 1997, 1995, 1999, and 2000. At the same time the winters have become milder with shorter very cold periods, and we have had prolonged summer droughts. According to the records of the Hungarian Meteorological Service (Szegő 2005; Takács-Sánta 2005) the number of hot days above 25 and 30 °C increased considerably in Hungary. The amount of precipitation, especially during winter, decreased.
It is highly likely that global warming is anthropogenic, due to the greenhouse effect of increasing CO2 and methane in the atmosphere (Vida 2001). Excessive CO2 emission began with deforestation in the Bronze Age and contributed to the end of the last glacial period. However, its sudden increase by the industrial revolution and especially during the last century (from 270 ppm to 380 ppm CO2 in the atmosphere) resulted in the 160 km NW shift of the annual isotherms in the Pannonian basin in Hungary.
Preface
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- By Michael Proctor, University of Exeter, UK, Tamás Pócs, Eszterházy College, Nancy Slack, Sage Colleges, USA
- Edited by Zoltán Tuba, Nancy G. Slack, Sage Colleges, New York, Lloyd R. Stark, University of Nevada, Las Vegas
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- Book:
- Bryophyte Ecology and Climate Change
- Published online:
- 05 October 2012
- Print publication:
- 06 January 2011, pp xvii-xxii
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Summary
This book is dedicated to Zoltán Tuba. Its origin was a symposium entitled Ecological Responses of Bryophytes to Changing Climate. It was presented at the American Bryological and Lichenological Society (ABLS) meeting with the Botanical Society of America (BSA) in Chico, California, in 2006. Nancy Slack, then president of ABLS, and Zoltán Tuba of Gödöllő University, Hungary, organized the symposium, which included speakers from many different countries. An editor at Cambridge University Press (England) saw the program on the Internet and asked the organizers to write a book on this subject. All the symposium speakers agreed to contribute chapters; subsequently, others doing important work in this field were asked to join them. Zoltán Tuba worked on the book with Nancy Slack from 2006 until shortly before his untimely death at 58 in July 2009. In the fall of 2009 Lloyd R. Stark, an active researcher in this field and co-author of two of the chapters, agreed to work with Nancy Slack to finish the book. Zoltán was a major contributor to research in ecophysiology of bryophytes in relation to climate change, as well as in other fields. He will be greatly missed as a scientist as well as a friend and co-worker.
A number of people have written to the present editors about Zoltán. In addition, part of an obituary by Zoltán's mentor, Professor Gábor Fekete: In Memoriam Zoltán Tuba (1951–2009), in Acta Botanica Hungarica vol. 52/1–2 (2010), is quoted here:
On July 4, 2009, Professor Zoltán Tuba, a leading expert in plant ecophysiology, left us forever.[…]
13 - Life in the dark dune spots of Mars: a testable hypothesis
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- By Eörs Szathmáry, Collegium Budapest, Tibor Gánti, Collegium Budapest, Tamás Pócs, Eszterházy Károly College, András Horváth, Konkoly Observatory, Ákos Kereszturi, Eötvös University, Szaniszló Bérczi, Eötvös University, András Sik, Eötvös University
- Edited by Ralph Pudritz, McMaster University, Ontario, Paul Higgs, McMaster University, Ontario, Jonathon Stone, McMaster University, Ontario
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- Book:
- Planetary Systems and the Origins of Life
- Published online:
- 13 August 2009
- Print publication:
- 06 December 2007, pp 241-262
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Summary
Introduction
This chapter presents one of the very rare exobiological hypotheses. The main thesis is that there could be life in the dark dune spots (DDSs) of the southern polar region of Mars, at latitudes between –60° and –80°. The spots have a characteristic annual morphological cycle and it is suspected that liquid water forms in them every year. We propose that a consortium of simple organisms (similar to bacteria) comes to life each year, driven by sunlight absorbed by the photosynthetic members of the consortium. A crucial feature of the proposed habitat is that life processes take place only under the cover of water ice/frost/snow. By the time this frost disappears from the dunes, the putative microbes, named Mars surface organisms (MSOs) must revert to a dormant state. The hypothesis has been worked out in considerable detail, it has not been convincingly refuted so far, and it is certainly testable by available scientific methods. We survey some of the history of, the logic behind, the testable predictions of, and the main challenges to the DDS-MSO hypothesis.
History
The spots in question were observed on images made by the Mars orbiter camera (MOC) on board the Mars Global Surveyor (MGS) spacecraft between 1998 and 1999 (images are credited to NASA/JPL/Malin Space Science Systems). These features appear in the southern and northern polar regions of the planet in the spring, and range in diameter from a few dozen to a few hundred metres.
13 - Bryogeography and conservation of bryophytes
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- By Benito C. Tan, National University of Singapore, Tamás Pócs, Botany, Esterházy College, EGER
- Edited by A. Jonathan Shaw, Duke University, North Carolina, Bernard Goffinet, University of Connecticut
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- Book:
- Bryophyte Biology
- Published online:
- 05 June 2012
- Print publication:
- 31 August 2000, pp 403-448
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Summary
Introduction
Except for the marine environment, bryophytes, as a group, are nearly cosmopolitan in distribution. Because of the small size of spores and the frequent occurrence of vegetative propagules, bryophytes are easily dispersed across the landscape. Consequently, many show much wider distribution patterns than the seed plants (Watson 1974). This is especially true at the family and generic levels. The purported greater age of bryophytes may have contributed further to the wider range of bryophytes (Schofield 1992).
The ecological and biological factors shaping the distribution patterns of seed plants have also affected the bryophytes. Indeed, like the seed plants, many bryophyte species found in the arctic and boreal zones are the same in North America, Asia, and Europe. In the tropics, there is a significant number of moss taxa that are pantropical, but the number is far lower when compared to the circumboreal taxa.
Although a great number of bryophyte genera and species are cosmopolitan and distributed throughout different climatic regions, many do exhibit a disrupted or narrow range. The latter represent the uncommon, rare and endemic bryophytes. Their ultimate survival is critically dependent on the preservation of their natural habitats.
Factors affecting the dispersal of bryophyte diaspores
Diaspores are defined as any propagative parts of bryophytes, be they spores or gemmae, capable of giving rise to a new individual. Among the bryophytes, few members, like the moss family Splachnaceae, produce sticky spores that are dependent on flies for their dispersal.