Bryophytes in perennially moist forests of Papua New Guinea: ecological orientation and predictions of disturbance effects.
01 Sep 1990-Botanical Journal of the Linnean Society (Blackwell Publishing Ltd)-Vol. 104, pp 281-291
TL;DR: Water relations of bryophytes must be understood along at least four dimensions: hydration/dehydration frequency; hydration duration; dehydration duration; degree of water loss; and biomass-dependent functions such that large colonies of b Bryophytes may maintain hydration longer than smaller colonies.
About: This article is published in Botanical Journal of the Linnean Society.The article was published on 1990-09-01. It has received 25 citations till now. The article focuses on the topics: Bryophyte & Temperate forest.
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TL;DR: In my opinion, the most crucial point is that students in tropical countries get not in contact with bryophytes, and mainly because of the lack of literature, which makes research difficult or even impossible in such countries.
Abstract: It is still a fact that most bryologists per area are found in the temperate regions of the northern hemisphere, who have spent up to 200 years (as in Europe) in the exploration of their bryofloras with the result that these countries have not only floras for identification of the comparably low number of species but some countries have already detailed grid maps of the distribution of all species. On the other hand, there are vast regions in the tropics which are very insufficiently explored. So far, the knowledge of bryophytes in these regions was predominantly provided by scientists from North America, Europe or Japan. Still much work is done by scientists and - during the past decades also increasingly - even by advanced amateurs from these countries. Regretably, these activities are often misunderstood by local biologists in the tropics and especially by the authorities of these states as scientific exploitation, and recently collecting of material for genetic studies as plundering of genetic ressources, which is nonsense but makes research difficult or even impossible in such countries. In this regard, the question raises why there are so few bryologists in tropical countries and even no bryologists in many countries? Usually, the lack of ressources such as laboratories, money, libraries, herbaria etc. is presented as arguments, which does not match the point, since many bryologists in industrial countries suffer from similar restrictions and sometimes have worth working consitions than colleagues in tropical countries, but make nevertheless valuable contributions to tropical bryology. Even amateurs have contributed a lot to tropical bryology in the past. The fewest bryologists work in such famous places as Missouri or New York Botanical Garden. Many of them are from eastern, former communistic countries and never gave up to promote tropical bryology under these conditions. In my opinion, the most crucial point is that students in tropical countries get not in contact with bryophytes, and mainly because of the lack of literature. Nobody can expect that students pick up a subject for their thesis if there is no literature available. This manual is therefore devoted to these students. Possibilities to gain a bryological training in industrial countries and paid by these countries were used only by few students, although available. And if these students do not come to us, we have to go to them (which is even cheaper). This is the reason for the increased number of courses on tropical bryology in the past.
94 citations
TL;DR: In this paper, microclimate factors and physiological responses determining survival and growth of epiphytic bryophytes in the lower canopy and trunk space of north-Andean cloud forests were analyzed.
Abstract: Aim Analysis of microclimate factors and physiological responses determining survival and growth of epiphytic bryophytes in the lower canopy and trunk space of north-Andean cloud forests.
Location Two cloud forests at 2000–2400 m in the northern Andes near Merida, Venezuela.
Methods Data-logging of dry and wet-season temperature, relative humidity (r.h.) and photosynthetically-active radiation (PAR) for month-long periods, and laboratory measurements of desiccation tolerance and light responses of selected epiphytic bryophytes.
Results Rainfall averages 20 mm or less in January and February, and 200 mm or more from August to October, but is very variable at all seasons. The proportion of time ‘wet’ (continuous 100% r.h.) in the months sampled ranged from 8.5% to 52.2% or more; a dry/wet-season range between 20% and 40% is probably commoner. The length of ‘wet’ and ‘dry’ periods approximated log-normal distributions, with mid-points for wet periods ranging from 2.8 to 10.7 h, and dry periods from 6.2 to 17.1 h. The longest recorded dry period was 143 h. Humidity typically rose during the night to > 90% r.h., reaching 100% for significant periods (implying cloudwater (fog) deposition) on about one night in two in all seasons. Of six bryophytes of pendulous growth form, all survived periods of at least a few days’ desiccation; most recovered better from high than low humidities. Measured 95% light-saturation values ranged from 110 to 256 μmol m−2 s−1, somewhat but not greatly higher than ambient light levels
Main conclusions Environmental conditions in the cloud forests are probably near-optimal for epiphytic bryophytes, but in even the wettest forest these plants must tolerate at least short periods of drying at any time of year, and longer periods seasonally. Interception of cloudwater droplets from moving air is likely to be an important source of water for bryophytes of pendant and other diffuse life forms, especially in periods of low rainfall. Absorption of water from near-saturated air is probably of little physiological significance. Bryophytes of these life-forms are notably conspicuous in tropical-montane cloud forests. They remain prominent into humid temperate regions such as southern Chile, New Zealand and Macaronesia, but progressively disappear at higher latitudes with the stresses of increasing seasonality.
78 citations
Cites background from "Bryophytes in perennially moist for..."
...According to Norris (1990), pendulous forms are an adaptation to frequent cycles (within a day or even a single hour) of hydration and dehydration....
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TL;DR: Foraging ecology and diet of eight species of epiphyte-searching insectivorous birds were studied in the Talamanca mountains of Costa Rica to determine degree of epIPhyte specialization, suggesting a continuum in foraging behaviors across the eight species.
Abstract: Foraging ecology and diet of eight species of epiphyte-searching insectivorous birds were studied in the Talamanca mountains ofCosta Rica to determine degree ofepiphyte specialization. To measure species' selectivity for epiphytic substrates, quantitative data on epiphyte availability was compared to actual bird use of epiphytes. Associations between each species and its foraging substrates, foraging maneuvers, and diets suggested a continuum in foraging behaviors across the eight species. At one end of this continuum were substraterestricted species, whose foraging behavior and prey choice appear to have been mediated by the nature of their foraging substrates. At the other end of the continuum were preyspecific species, whose foraging behavior and substrate choice appear to have been determined by the nature of their prey. Four species in the study area (approximately 8% of the resident avifauna) were epiphyte specialists: Pseudocolaptes lawrencii on arboreal bromeliads, Margarornis rubiginosus on bryophytes, Lepidocolaptes affinis on bryophytes and foliose lichens, and Troglodytes ochraceus on epiphytic root masses.
58 citations
TL;DR: Ordination analysis revealed one dominant pattern in bryophyte composition in the inner canopy: a desiccation gradient ranging from sheltered sites in the intact forest trees to exposed Sites in the isolated trees.
Abstract: A total of 127 bryophyte species (50 mosses, 76 liverworts, and 1 hornwort) was encountered in the inner crowns of six Ficus tuerckheimmi trees in a lower montane wet forest landscape: 109 on three intact forest trees and 76 on three isolated trees. Fifty-two species were found only on the intact forest trees, while only 18 species were exclusive to the isolated trees. Bryophyte species richness, bryophyte cover, and the frequency of pendents, tall turfs, tails, and fans were significantly higher in intact forest trees. Inner crowns of isolated trees had higher rates of evaporation, had higher macrolichen cover, and were more exposed to sunlight than inner crowns of intact forest trees. Ordination analysis revealed one dominant pattern in bryophyte composition in the inner canopy: a desiccation gradient ranging from sheltered sites in the intact forest trees to exposed sites in the isolated trees.
55 citations
TL;DR: Drivers other than temperature-dependent metabolic rates must be more important in explaining the altitudinal gradient in bryophyte abundance, but the main effect of temperature probably lies in increasing evaporation rates, thus restricting the time available for photosynthetic carbon gain, rather than in increasing nightly respiration rates.
47 citations
Cites background from "Bryophytes in perennially moist for..."
...However, the timing and duration of moisture availability determines physiological activity and, consequently, carbon gains and losses (Norris, 1990)....
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References
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1,184 citations
01 Jan 1982
TL;DR: In the following pages it is hoped that the life-forms of bryophytes are very different in several plant formations and that this diversity is closely related to their life conditions.
Abstract: Unlike most of the higher plants, bryophytes are not found as single individuals but in groups of individuals which have characteristic features depending on their family, genus or species. These features enable the experienced bryologist to identify many genera and often even species from quite a distance. The shape and structure of the groups of individuals are determined by two different factors. The protonema produced from a spore forms one to several buds, each of which grows to become an ‘individual’. The individuals are thus at the very outset part of an assemblage. Each individual (moss shoot) has a genetically fixed method of ramification, depending on species, genus or family, a particular ‘growth-form’ in the narrower meaning of the term. Assemblage of individuals and growth-form, modified by external conditions, together provide the characteristics which can be described as the ‘life-form’. In the following pages we hope to show that the life-forms of bryophytes are very different in several plant formations and that this diversity is closely related to their life conditions.
226 citations
170 citations
TL;DR: A wide range of host tree species in both temperate and tropical rainforests gain access to these nutrients by putting forth extensive networks of adventitious roots beneath the epiphyte mats they support.
Abstract: Accumulations of living and dead epiphytes in the canopy of rainforest trees provide an aboveground nutrient resource. A wide range of host tree species in both temperate and tropical rainforests gain access to these nutrients by putting forth extensive networks of adventitious roots beneath the epiphyte mats they support.
163 citations
01 Jan 1982
TL;DR: The tropical forests were known for a long period simply as an inexhaustible El Dorado of new bryophyte species and we did not know much about their ecology as mentioned in this paper.
Abstract: The tropical forests were known for a long period simply as an inexhaustible El Dorado of new bryophyte species and we did not know much about their ecology. Even in the 1950s Richards (1954), a known authority on bryophyte ecology, complained about the scantiness of our knowledge about the bryophyte communities in the tropical rain forests.
144 citations