Pub Date : 2004-01-01DOI: 10.1080/03746600408685070
G. R. Miller
Summary The alpine gentian (Gentiana nivalis L.) is a mountain rarity found at only two localities in Britain. It is an annual, establishing anew from seed each year and so the size and persistence of its seed bank is important for survival. Seed bank size was measured in summer, before seeds were shed, by sampling from soils at two sites where the alpine gentian is common. As the seeds do not germinate readily in the laboratory, it was assumed that all apparently healthy seeds extracted from the soils were alive and viable. This assumption was corroborated when 95–97% of seeds buried experimentally for 9–12 years germinated after repeated applications of gibberellic acid solution over a period of 6 months. Densities of naturally buried alpine gentian seeds at the two sites ranged from 1.3 to 6.8 × 103 seeds m-2 and they comprised a major component of the community seed bank, disproportionately greater than the abundance of parent plants in the vegetation. The half-life of experimentally buried seeds was estimated as 15 or 32 years, depending on depth of burial and soil type. The findings explain why alpine gentian numbers can recover quickly after a population crash and emphasise the importance of the seed bank to the species' long-term survival in the montane environment.
{"title":"Size and longevity of seed banks of alpine gentian (Gentiana nivalis L.)","authors":"G. R. Miller","doi":"10.1080/03746600408685070","DOIUrl":"https://doi.org/10.1080/03746600408685070","url":null,"abstract":"Summary The alpine gentian (Gentiana nivalis L.) is a mountain rarity found at only two localities in Britain. It is an annual, establishing anew from seed each year and so the size and persistence of its seed bank is important for survival. Seed bank size was measured in summer, before seeds were shed, by sampling from soils at two sites where the alpine gentian is common. As the seeds do not germinate readily in the laboratory, it was assumed that all apparently healthy seeds extracted from the soils were alive and viable. This assumption was corroborated when 95–97% of seeds buried experimentally for 9–12 years germinated after repeated applications of gibberellic acid solution over a period of 6 months. Densities of naturally buried alpine gentian seeds at the two sites ranged from 1.3 to 6.8 × 103 seeds m-2 and they comprised a major component of the community seed bank, disproportionately greater than the abundance of parent plants in the vegetation. The half-life of experimentally buried seeds was estimated as 15 or 32 years, depending on depth of burial and soil type. The findings explain why alpine gentian numbers can recover quickly after a population crash and emphasise the importance of the seed bank to the species' long-term survival in the montane environment.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129829402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685066
G. McGowan, Johanna Joensalo, R. Naylor
Summary Females and males of dioecious species may not allocate the same proportions of assimilate to plant protection and so may be differentially grazed. The distribution range of the dioecious, coniferous shrub, juniper (Juniperus communis) is declining in the UK and populations are becoming fragmented. The main aims of this study were to (i) assess the sex structure of populations of prostrate juniper at four sites in northern Scotland and (ii) assess the extent of grazing on individual plants. A total of 518 prostrate juniper plants were inspected in the four populations. The sex of 30–85 % of them could not be determined. There were differences between the sites in grazing intensity, plant density, plant size, and the proportion of females. Between June and September, there was almost no grazing of current growth and no difference between males and females in the amount of grazing. Most grazing took place over winter. This was supported by the observation that dung counts over summer did not correlate with grazing of current or old shoots. Female, male and unsexable plants had similar size ranges. Female and unsexable plants had similar numbers and proportions of old shoots grazed but male plants had significantly less. This suggests that many of the unsexable plants were non-reproducing females and that the greater grazing on unsexable plants might be responsible for the cessation of reproduction. The impact of differential winter grazing of prostrate female and male juniper plants is discussed in relation to the conservation of this species in Scotland and the UK.
{"title":"Differential grazing of female and male plants of prostrate juniper (Juniperus communis L.)","authors":"G. McGowan, Johanna Joensalo, R. Naylor","doi":"10.1080/03746600408685066","DOIUrl":"https://doi.org/10.1080/03746600408685066","url":null,"abstract":"Summary Females and males of dioecious species may not allocate the same proportions of assimilate to plant protection and so may be differentially grazed. The distribution range of the dioecious, coniferous shrub, juniper (Juniperus communis) is declining in the UK and populations are becoming fragmented. The main aims of this study were to (i) assess the sex structure of populations of prostrate juniper at four sites in northern Scotland and (ii) assess the extent of grazing on individual plants. A total of 518 prostrate juniper plants were inspected in the four populations. The sex of 30–85 % of them could not be determined. There were differences between the sites in grazing intensity, plant density, plant size, and the proportion of females. Between June and September, there was almost no grazing of current growth and no difference between males and females in the amount of grazing. Most grazing took place over winter. This was supported by the observation that dung counts over summer did not correlate with grazing of current or old shoots. Female, male and unsexable plants had similar size ranges. Female and unsexable plants had similar numbers and proportions of old shoots grazed but male plants had significantly less. This suggests that many of the unsexable plants were non-reproducing females and that the greater grazing on unsexable plants might be responsible for the cessation of reproduction. The impact of differential winter grazing of prostrate female and male juniper plants is discussed in relation to the conservation of this species in Scotland and the UK.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128546255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685064
R. Crawford
Summary Long-term survival is a feature of plant life in the Arctic both for individuals and species. Stems of willow can be centuries old and vegetatively reproducing clones can have their ages counted in millennia. Circum-polar examination of chloroplast DNA has made it possible to trace the migration of Saxifraga oppositifolia clades over a period of 4–5 million years and demonstrate that this species maintained a presence north of the ice sheets during the last glacial maximum and probably longer. There has long been speculation that the Arctic has two distinct floras, an ancient autochthonous flora (an original endemic flora) that has survived since the Pleistocene and an invading flora that has immigrated into the Arctic during late glacial and post-glacial times. It is therefore probable that Saxifraga oppositifolia is not alone in its Pleistocene occupation of High Arctic polar deserts. The ancient autochthonous flora consists of conservative species with widespread distributions and chromosome counts that are simple diploids, with little evidence of allo-polyploidisation. This is in marked contrast to the majority of the species that are now present in the Arctic which are polyploid. This paper considers some of the physiological and genetic properties of polar-plant-populations that may facilitate persistence in uncertain and heterogeneous adverse environments. Attention is drawn to some possible advantages that diploid species may possess over polyploids, in having a mutualistic rather than a competitive relationship between varying sub-populations and local ecotypes whereby, diploid species, consisting of many variable populations that readily interbreed, provide a mutually accessible source of genetic variation that may have contributed to long-term survival.
{"title":"Long-term plant survival at high latitudes","authors":"R. Crawford","doi":"10.1080/03746600408685064","DOIUrl":"https://doi.org/10.1080/03746600408685064","url":null,"abstract":"Summary Long-term survival is a feature of plant life in the Arctic both for individuals and species. Stems of willow can be centuries old and vegetatively reproducing clones can have their ages counted in millennia. Circum-polar examination of chloroplast DNA has made it possible to trace the migration of Saxifraga oppositifolia clades over a period of 4–5 million years and demonstrate that this species maintained a presence north of the ice sheets during the last glacial maximum and probably longer. There has long been speculation that the Arctic has two distinct floras, an ancient autochthonous flora (an original endemic flora) that has survived since the Pleistocene and an invading flora that has immigrated into the Arctic during late glacial and post-glacial times. It is therefore probable that Saxifraga oppositifolia is not alone in its Pleistocene occupation of High Arctic polar deserts. The ancient autochthonous flora consists of conservative species with widespread distributions and chromosome counts that are simple diploids, with little evidence of allo-polyploidisation. This is in marked contrast to the majority of the species that are now present in the Arctic which are polyploid. This paper considers some of the physiological and genetic properties of polar-plant-populations that may facilitate persistence in uncertain and heterogeneous adverse environments. Attention is drawn to some possible advantages that diploid species may possess over polyploids, in having a mutualistic rather than a competitive relationship between varying sub-populations and local ecotypes whereby, diploid species, consisting of many variable populations that readily interbreed, provide a mutually accessible source of genetic variation that may have contributed to long-term survival.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134380698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685076
M. Fenner
Summary The seed size that is characteristic of each plant species is of central importance for their regeneration because of its effect on dispersability and seedling establishment. The chemical composition of the stored nutrients is also important in the early stages of growth. The factors that influence individual seed size and nutrient allocation during development on the parent plant are examined, and allocation strategies are compared in different plants. Experiments to determine the effective supply of different elements in seeds are reviewed. The apparent imbalance in the seed nutrient allocation is discussed. Mineral use in early seedling growth is described and the exhaustion of internal nutrient reserves is considered as a means of defining the end of seedling growth phase.
{"title":"Seed size and chemical composition: the allocation of minerals to seeds and their use in early seedling growth","authors":"M. Fenner","doi":"10.1080/03746600408685076","DOIUrl":"https://doi.org/10.1080/03746600408685076","url":null,"abstract":"Summary The seed size that is characteristic of each plant species is of central importance for their regeneration because of its effect on dispersability and seedling establishment. The chemical composition of the stored nutrients is also important in the early stages of growth. The factors that influence individual seed size and nutrient allocation during development on the parent plant are examined, and allocation strategies are compared in different plants. Experiments to determine the effective supply of different elements in seeds are reviewed. The apparent imbalance in the seed nutrient allocation is discussed. Mineral use in early seedling growth is described and the exhaustion of internal nutrient reserves is considered as a means of defining the end of seedling growth phase.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128536915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685074
J. Mackintosh
Summary National Vegetation Classification (NVC) data from surveys of Scottish unimproved lowland grasslands were reviewed. The surveys dated from 1980 to 2000. The mapped area of each lowland grassland NVC type was measured or, where vegetation maps were not of sufficient quality, estimated. These measurements and estimates were summed to give the total recorded area of each lowland grassland NVC type. An estimate of the total area likely to occur throughout Scotland was made for the more thoroughly recorded lowland grassland NVC types. The data from this review has been used to create Scottish Natural Heritage's Lowland Grassland Database, containing details of all lowland grassland sites recorded by the grassland surveys, their grid reference, conservation status, site area, surveyor, date of survey, NVC lowland grassland types present and their areas. Council Area, old local authority District and SNH Area are also included. A total of 8700 ha of unimproved lowland grassland NVC types (excluding coastal grasslands) has been recorded in Scotland. This habitat is semi-natural and of high conservation value. The total area of unimproved lowland grassland in Scotland is estimated to be in the order of 30,000 ha.
{"title":"Distribution and extent of unimproved lowland grassland National Vegetation Classification (NVC) types in Scotland","authors":"J. Mackintosh","doi":"10.1080/03746600408685074","DOIUrl":"https://doi.org/10.1080/03746600408685074","url":null,"abstract":"Summary National Vegetation Classification (NVC) data from surveys of Scottish unimproved lowland grasslands were reviewed. The surveys dated from 1980 to 2000. The mapped area of each lowland grassland NVC type was measured or, where vegetation maps were not of sufficient quality, estimated. These measurements and estimates were summed to give the total recorded area of each lowland grassland NVC type. An estimate of the total area likely to occur throughout Scotland was made for the more thoroughly recorded lowland grassland NVC types. The data from this review has been used to create Scottish Natural Heritage's Lowland Grassland Database, containing details of all lowland grassland sites recorded by the grassland surveys, their grid reference, conservation status, site area, surveyor, date of survey, NVC lowland grassland types present and their areas. Council Area, old local authority District and SNH Area are also included. A total of 8700 ha of unimproved lowland grassland NVC types (excluding coastal grasslands) has been recorded in Scotland. This habitat is semi-natural and of high conservation value. The total area of unimproved lowland grassland in Scotland is estimated to be in the order of 30,000 ha.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127970983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685065
D. Kohn, P. Lusby
Summary Twinflower, Linnaea borealis L., is a creeping, woody, clonal perennial nationally scarce in the UK, with its distribution confined to discrete patches in Scotland. Translocation of twinflower from natural patches into either existing patches, with a view to increasing genetic variation and outcrossing rates, or to unoccupied habitat, with a view to increasing its overall prevalence, could effectively increase the species' viability. In a small pilot experiment 38 shoots were moved from a vigorous patch in the Scottish Borders into two overtly hospitable clearings within the same woodland. Two years later 18 shoots (47%) survived and three years later four shoots (10.5%) remained, with die-back occurring irregularly over shoots of different initial lengths. No measured character of the original shoots explained which survived at each time interval. The most likely cause of the high mortality was competition from established grasses (Deschampsia flexuosa) which prevented growth and the formation of new roots along stolons. The study should help focus future efforts to determine best methods of increasing establishment of twinflower in Scotland.
{"title":"Translocation of twinflower (Linnaea borealis L.) in the Scottish Borders","authors":"D. Kohn, P. Lusby","doi":"10.1080/03746600408685065","DOIUrl":"https://doi.org/10.1080/03746600408685065","url":null,"abstract":"Summary Twinflower, Linnaea borealis L., is a creeping, woody, clonal perennial nationally scarce in the UK, with its distribution confined to discrete patches in Scotland. Translocation of twinflower from natural patches into either existing patches, with a view to increasing genetic variation and outcrossing rates, or to unoccupied habitat, with a view to increasing its overall prevalence, could effectively increase the species' viability. In a small pilot experiment 38 shoots were moved from a vigorous patch in the Scottish Borders into two overtly hospitable clearings within the same woodland. Two years later 18 shoots (47%) survived and three years later four shoots (10.5%) remained, with die-back occurring irregularly over shoots of different initial lengths. No measured character of the original shoots explained which survived at each time interval. The most likely cause of the high mortality was competition from established grasses (Deschampsia flexuosa) which prevented growth and the formation of new roots along stolons. The study should help focus future efforts to determine best methods of increasing establishment of twinflower in Scotland.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122945270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685073
R. Watling
Historical background Sir William Wright Smith gained his early botanical expertise via a lectureship at Edinburgh University and four years in India where he was Curator of the Government Herbarium at the Royal Botanic Gardens, Calcutta, Acting Director of the Botanical Survey of India and Director of the Lloyd Botanic Garden, Darjeeling, the Sikkim cinchona plantations and the quinine factory in Mungpoo. Whilst in India he gained invaluable botanical knowledge in expeditions to littleknown areas of the Himalayas, especially in Sikkim and the borders of India with Nepal, Tibet and with Bhutan. On his return to Edinburgh in 1911 he became Deputy Keeper of the Botanic Garden and in 1922 became Professor of Botany and Regius Keeper at the Botanic Garden (Matthews, 1957). Through his interests especially in the genus Rhododendron, one of his chosen genera of study in his later years, he was well acquainted with the best horticultural collections in Scotland, indeed in many cases it was after discussion with him that many of these plantings were instigated. One of these prize collections was on an estate in the Scottish Borders, which boasted specimens collected by David Douglas in North America, some of the first plantings of exotic European trees and many, then recently introduced, Chinese woody plants. This same estate possessed an extraordinary wood where you could find flesh, fish and fruit all on the same tree, a mythical wood commented on in several histories of the Borders, including 1715 papers belonging to Dr Alexander Penicuik. The myth was enhanced by the fact that Merlin, King Arthur's magician, is reputed to be buried quite close at Drumelzier. The story of the extraordinary wood results from the fact that nearly 300 years ago there was a heronry in the pear orchard and these birds fished for eels and trout in the nearby Tweed and took them back to their nests; some eels escaped and so were seen in the wood trying to return to the river. These, with the pears and the herons, which have been eaten in historic times, provided the myth and the wood became known as Heron Wood! The wood is on the slopes of a stream issuing from heathland and hill-pasture known as The Scrape Burn and is now an integral part of the Dawyck Botanic Garden, an out station of the Royal Botanic Garden, Edinburgh, situated less than 60 km from Edinburgh in the Borders, approximately equidistant from Glasgow and Edinburgh. Dawyck Botanic Garden is situated in a track of agricultural policies near
{"title":"Dawyck Botanic Garden: the Heron Wood cryptogamic project","authors":"R. Watling","doi":"10.1080/03746600408685073","DOIUrl":"https://doi.org/10.1080/03746600408685073","url":null,"abstract":"Historical background Sir William Wright Smith gained his early botanical expertise via a lectureship at Edinburgh University and four years in India where he was Curator of the Government Herbarium at the Royal Botanic Gardens, Calcutta, Acting Director of the Botanical Survey of India and Director of the Lloyd Botanic Garden, Darjeeling, the Sikkim cinchona plantations and the quinine factory in Mungpoo. Whilst in India he gained invaluable botanical knowledge in expeditions to littleknown areas of the Himalayas, especially in Sikkim and the borders of India with Nepal, Tibet and with Bhutan. On his return to Edinburgh in 1911 he became Deputy Keeper of the Botanic Garden and in 1922 became Professor of Botany and Regius Keeper at the Botanic Garden (Matthews, 1957). Through his interests especially in the genus Rhododendron, one of his chosen genera of study in his later years, he was well acquainted with the best horticultural collections in Scotland, indeed in many cases it was after discussion with him that many of these plantings were instigated. One of these prize collections was on an estate in the Scottish Borders, which boasted specimens collected by David Douglas in North America, some of the first plantings of exotic European trees and many, then recently introduced, Chinese woody plants. This same estate possessed an extraordinary wood where you could find flesh, fish and fruit all on the same tree, a mythical wood commented on in several histories of the Borders, including 1715 papers belonging to Dr Alexander Penicuik. The myth was enhanced by the fact that Merlin, King Arthur's magician, is reputed to be buried quite close at Drumelzier. The story of the extraordinary wood results from the fact that nearly 300 years ago there was a heronry in the pear orchard and these birds fished for eels and trout in the nearby Tweed and took them back to their nests; some eels escaped and so were seen in the wood trying to return to the river. These, with the pears and the herons, which have been eaten in historic times, provided the myth and the wood became known as Heron Wood! The wood is on the slopes of a stream issuing from heathland and hill-pasture known as The Scrape Burn and is now an integral part of the Dawyck Botanic Garden, an out station of the Royal Botanic Garden, Edinburgh, situated less than 60 km from Edinburgh in the Borders, approximately equidistant from Glasgow and Edinburgh. Dawyck Botanic Garden is situated in a track of agricultural policies near","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131545875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685075
M. J. Richardson
Summary Fifty-seven species of coprophilous fungi are recorded from 14 dung samples collected from the Souss Valley area of southern Morocco that were incubated in moist chambers. Several new records for Morocco are reported. Evidence for reduced diversity due to the severely degraded nature of the habitats in which the samples were collected is discussed.
{"title":"Coprophilous fungi from Morocco","authors":"M. J. Richardson","doi":"10.1080/03746600408685075","DOIUrl":"https://doi.org/10.1080/03746600408685075","url":null,"abstract":"Summary Fifty-seven species of coprophilous fungi are recorded from 14 dung samples collected from the Souss Valley area of southern Morocco that were incubated in moist chambers. Several new records for Morocco are reported. Evidence for reduced diversity due to the severely degraded nature of the habitats in which the samples were collected is discussed.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114543051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685069
G. R. Miller, C. Geddes
Summary The seed content of individual capsules of alpine gentian (Gentiana nivalis L.), a rare annual of Scottish mountains, was compared amongst (a) single- and multi-flowered plants and (b) the years 1987–92 inclusive. Capsules contained two types of seeds, ‘live’ seeds that were terete and apparently viable, and ‘aborted’ seeds that were shrunken and clearly dead. The topmost capsule on plants with two-five flowers contained two-three times the number of live seeds found in capsules from plants with a single flower. The mean annual production of live seeds per plant ranged from 176 in single-flowered plants through 445, 580, 983 and 1145 in plants with two, three, four and five flowers respectively. The mean live seed content of capsules varied annually, depending on the numbers of seeds that aborted. Annual variation in the proportion of aborted seeds was negatively correlated with mean maximum temperature during July, when the plants began flowering. It is suggested that cold temperatures in July possibly inhibited the activity of pollinating insects and the growth of pollen tubes. The results are discussed in the context of possible future changes in the Scottish climate.
{"title":"Seed-setting by alpine gentian (Gentiana nivalis L.)","authors":"G. R. Miller, C. Geddes","doi":"10.1080/03746600408685069","DOIUrl":"https://doi.org/10.1080/03746600408685069","url":null,"abstract":"Summary The seed content of individual capsules of alpine gentian (Gentiana nivalis L.), a rare annual of Scottish mountains, was compared amongst (a) single- and multi-flowered plants and (b) the years 1987–92 inclusive. Capsules contained two types of seeds, ‘live’ seeds that were terete and apparently viable, and ‘aborted’ seeds that were shrunken and clearly dead. The topmost capsule on plants with two-five flowers contained two-three times the number of live seeds found in capsules from plants with a single flower. The mean annual production of live seeds per plant ranged from 176 in single-flowered plants through 445, 580, 983 and 1145 in plants with two, three, four and five flowers respectively. The mean live seed content of capsules varied annually, depending on the numbers of seeds that aborted. Annual variation in the proportion of aborted seeds was negatively correlated with mean maximum temperature during July, when the plants began flowering. It is suggested that cold temperatures in July possibly inhibited the activity of pollinating insects and the growth of pollen tubes. The results are discussed in the context of possible future changes in the Scottish climate.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126916844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-01-01DOI: 10.1080/03746600408685068
R. Watling, M. Seaward
Summary Forty-one fungal taxa, the majority macromycetes, were recorded from the Chagos Archipelago and the Seychelles, 29 and 17 respectively, with five, all macrofungi, common to both. Most of the fungi recorded are of wide distribution in the palaeotropics being either associated on these Indian Ocean islands with Cocos plantations and disturbed and/or anthropogenic sites. Some are even pantropical and none appears to be distinctive to these islands. A single collection (Sphinctrina tubiformis) is noted from Aldabra.
{"title":"Some fungi of Indian Ocean Islands","authors":"R. Watling, M. Seaward","doi":"10.1080/03746600408685068","DOIUrl":"https://doi.org/10.1080/03746600408685068","url":null,"abstract":"Summary Forty-one fungal taxa, the majority macromycetes, were recorded from the Chagos Archipelago and the Seychelles, 29 and 17 respectively, with five, all macrofungi, common to both. Most of the fungi recorded are of wide distribution in the palaeotropics being either associated on these Indian Ocean islands with Cocos plantations and disturbed and/or anthropogenic sites. Some are even pantropical and none appears to be distinctive to these islands. A single collection (Sphinctrina tubiformis) is noted from Aldabra.","PeriodicalId":365547,"journal":{"name":"Botanical Journal of Scotland","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123496882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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