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Titre :	Restoration in applied ecology : editor's introduction
Type de document :	Tiré à part de revue
Auteurs :	S.J. Ormerod
Année de publication :	2003
Importance :	44-50
Langues :	Anglais (eng)
Catégories :	[CBNPMP-Thématique] Revégétalisation
Lien pérenne :	DOI : 10.1046/j.1365-2664.2003.00799.x
Permalink :	https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=131607

Restoration in applied ecology : editor's introduction [Tiré à part de revue] / S.J. Ormerod . - 2003 . - 44-50.
Langues : Anglais (eng)

Catégories :	[CBNPMP-Thématique] Revégétalisation
Lien pérenne :	DOI : 10.1046/j.1365-2664.2003.00799.x
Permalink :	https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=131607

Titre :	Modelling the emergence response of weed seeds to burial depth : interactions with seed density, weight and shape
Type de document :	Tiré à part de revue
Auteurs :	A.C. Grundy ; Andrew Mead ; S. Burston
Année de publication :	2003
Importance :	757-770
Langues :	Anglais (eng)
Catégories :	[CBNPMP-Thématique] Banque de semences dans le sol [CBNPMP-Thématique] Germination : généralités [CBNPMP-Thématique] Longévité des semences [CBNPMP-Thématique] Mauvaises herbes
Résumé :	1 Weeds play an important role in arable and horticultural habitats, and models are being developed to improve our understanding of their population dynamics. The position of a weed seed in the soil profile influences the probability of a seed germinating, emerging successfully and its relative time of emergence. Identifying a relationship between the shape or weight of a seed and its ability to emerge from depth may allow the development of generic models. The aim of this study was to quantify seed response to burial depth, to improve the wider application of existing seedling emergence models. 2 A field experiment used weed seeds sown at different depths and densities in a standard substrate. In addition, two laboratory studies used pre-germinated seeds of the same range of species, buried at a range of depths in optimum conditions using the same substrate. These studies explored the effects of seed size, shape and sowing density on seedling emergence and also enabled reserve-dependent pre-emergence mortality to be quantified. 3 The largest and heaviest of the seeds tested overall, Veronica hederifolia, emerged from the greatest depth (8 cm). In contrast, Tripleurospermum inodorum and Veronica arvensis, the two smallest species, showed a sharp decline when burial exceeded 1 cm. However, the link between seed shape or weight and the ability to emerge from depth suggests a complex relationship. Given optimum conditions, some species (Stellaria media and Chenopodium album) have the physical reserves to emerge from a wider range of burial depths than normally observed in the field, suggesting an ability to exploit opportunities when they occur. 4 For some species, emergence was reduced at high seed densities (e.g. Veronica arvensis). These responses may be associated with traits that have evolved to counteract sibling competition. 5 Synthesis and applications. Generic models identifying the maximum depths for seed germination and emergence have a number of practical applications. For example, they can be used to target cultivation to deplete the weed seed bank or to prescribe the optimum depth of mulches to favour certain species. Our model showed that, in general, larger-seeded species emerged from deeper in the soil, but the relationship between seed size and shape and emergence was complex, possibly species specific. Our germination data may also assist our understanding of the relative importance of different causes of seed losses, particularly from different zones of the soil profile, such as the soil surface. Understanding the component processes of seed behaviour and germination is essential to developing sustainable weed management practices in agriculture and horticulture, and the work reported here contributes to a larger programme modelling weed seed bank population dynamics.
Lien pérenne :	DOI : 10.1046/j.1365-2664.2003.00836.x
Permalink :	https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=134188

Modelling the emergence response of weed seeds to burial depth : interactions with seed density, weight and shape [Tiré à part de revue] / A.C. Grundy ; Andrew Mead ; S. Burston . - 2003 . - 757-770.
Langues : Anglais (eng)

Catégories :	[CBNPMP-Thématique] Banque de semences dans le sol [CBNPMP-Thématique] Germination : généralités [CBNPMP-Thématique] Longévité des semences [CBNPMP-Thématique] Mauvaises herbes
Résumé :	1 Weeds play an important role in arable and horticultural habitats, and models are being developed to improve our understanding of their population dynamics. The position of a weed seed in the soil profile influences the probability of a seed germinating, emerging successfully and its relative time of emergence. Identifying a relationship between the shape or weight of a seed and its ability to emerge from depth may allow the development of generic models. The aim of this study was to quantify seed response to burial depth, to improve the wider application of existing seedling emergence models. 2 A field experiment used weed seeds sown at different depths and densities in a standard substrate. In addition, two laboratory studies used pre-germinated seeds of the same range of species, buried at a range of depths in optimum conditions using the same substrate. These studies explored the effects of seed size, shape and sowing density on seedling emergence and also enabled reserve-dependent pre-emergence mortality to be quantified. 3 The largest and heaviest of the seeds tested overall, Veronica hederifolia, emerged from the greatest depth (8 cm). In contrast, Tripleurospermum inodorum and Veronica arvensis, the two smallest species, showed a sharp decline when burial exceeded 1 cm. However, the link between seed shape or weight and the ability to emerge from depth suggests a complex relationship. Given optimum conditions, some species (Stellaria media and Chenopodium album) have the physical reserves to emerge from a wider range of burial depths than normally observed in the field, suggesting an ability to exploit opportunities when they occur. 4 For some species, emergence was reduced at high seed densities (e.g. Veronica arvensis). These responses may be associated with traits that have evolved to counteract sibling competition. 5 Synthesis and applications. Generic models identifying the maximum depths for seed germination and emergence have a number of practical applications. For example, they can be used to target cultivation to deplete the weed seed bank or to prescribe the optimum depth of mulches to favour certain species. Our model showed that, in general, larger-seeded species emerged from deeper in the soil, but the relationship between seed size and shape and emergence was complex, possibly species specific. Our germination data may also assist our understanding of the relative importance of different causes of seed losses, particularly from different zones of the soil profile, such as the soil surface. Understanding the component processes of seed behaviour and germination is essential to developing sustainable weed management practices in agriculture and horticulture, and the work reported here contributes to a larger programme modelling weed seed bank population dynamics.
Lien pérenne :	DOI : 10.1046/j.1365-2664.2003.00836.x
Permalink :	https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=134188

Titre :	Microsite availability and establishment of native species on degraded and reclaimed sites
Type de document :	Tiré à part de revue
Auteurs :	Asrun Elmarsdottir ; Ása L. Aradóttir ; Trlica
Année de publication :	2003
Importance :	815-823
Langues :	Anglais (eng)
Catégories :	[CBNPMP-Thématique] Restauration des écosystèmes [CBNPMP-Thématique] Revégétalisation
Note de contenu :	1 Restoration of native plant communities on previously disturbed land requires the identification and modification of environmental factors that impede or restrict ecosystem succession or development. One of the key factors in successful reclamation is to ensure colonization and persistence of native species within an area. Therefore, the identification of microsite types that favour colonization by native species should improve our ability to successfully reclaim degraded areas. 2 The objectives of this study were to (i) identify and describe microsite types that were conducive to the establishment of five native plant species (Euphrasia frigida, Galium normanii, Thymus praecox, Cerastium spp. and Rumex acetosa) on degraded and reclaimed sites in Iceland; and (ii) to determine the effects of reclamation activities that included the application of manure and inorganic fertilizer on the distribution of microsite types and seedling establishment. Reclamation sites of different ages were examined on an eroded area where the target community was a grass or shrub heath. 3 The spatial distribution of plant establishment was not random but varied among microsite types and study sites. More seedlings than expected were found in microsite types characterized by small rocks and biological soil crusts. These may have entrapped seed and provided more soil stability and moisture than other microsite types. The cover of these microsite types varied among the study sites but the pattern of seedling establishment among the five native forbs was similar. 4 Synthesis and applications. Practical reclamation methods are improved by identifying those factors that promote successful seedling establishment by native species. Application of fertilizer without additional seeding proved to be a simple reclamation approach that increased the availability of one favourable microsite type, enhanced the establishment of native species and subsequently allowed vegetation cover to expand. Seed of native plants may be difficult to obtain commercially, but this approach can be used on degraded land where propagules are available but recovery is slowed by soil instability or nutrient limitations.
Lien pérenne :	DOI : 10.1046/j.1365-2664.2003.00848.x
Permalink :	https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=134222

Microsite availability and establishment of native species on degraded and reclaimed sites [Tiré à part de revue] / Asrun Elmarsdottir ; Ása L. Aradóttir ; Trlica . - 2003 . - 815-823.
Langues : Anglais (eng)

Catégories :	[CBNPMP-Thématique] Restauration des écosystèmes [CBNPMP-Thématique] Revégétalisation
Note de contenu :	1 Restoration of native plant communities on previously disturbed land requires the identification and modification of environmental factors that impede or restrict ecosystem succession or development. One of the key factors in successful reclamation is to ensure colonization and persistence of native species within an area. Therefore, the identification of microsite types that favour colonization by native species should improve our ability to successfully reclaim degraded areas. 2 The objectives of this study were to (i) identify and describe microsite types that were conducive to the establishment of five native plant species (Euphrasia frigida, Galium normanii, Thymus praecox, Cerastium spp. and Rumex acetosa) on degraded and reclaimed sites in Iceland; and (ii) to determine the effects of reclamation activities that included the application of manure and inorganic fertilizer on the distribution of microsite types and seedling establishment. Reclamation sites of different ages were examined on an eroded area where the target community was a grass or shrub heath. 3 The spatial distribution of plant establishment was not random but varied among microsite types and study sites. More seedlings than expected were found in microsite types characterized by small rocks and biological soil crusts. These may have entrapped seed and provided more soil stability and moisture than other microsite types. The cover of these microsite types varied among the study sites but the pattern of seedling establishment among the five native forbs was similar. 4 Synthesis and applications. Practical reclamation methods are improved by identifying those factors that promote successful seedling establishment by native species. Application of fertilizer without additional seeding proved to be a simple reclamation approach that increased the availability of one favourable microsite type, enhanced the establishment of native species and subsequently allowed vegetation cover to expand. Seed of native plants may be difficult to obtain commercially, but this approach can be used on degraded land where propagules are available but recovery is slowed by soil instability or nutrient limitations.
Lien pérenne :	DOI : 10.1046/j.1365-2664.2003.00848.x
Permalink :	https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=134222