Topic
Deschampsia
About: Deschampsia is a research topic. Over the lifetime, 139 publications have been published within this topic receiving 3125 citations.
Papers published on a yearly basis
Papers
TL;DR: One of the earliest experimental studies of the ecological requirements of a single species to be published in The Journal of Ecology was contributed by Olsen and is devoted to an investigation of the distribution of nettle (Urtica dioica) in Danish woodlands in relation to soil conditions.
Abstract: One of the earliest experimental studies of the ecological requirements of a single species to be published in The Journal of Ecology was contributed by Olsen and is devoted to an investigation of the distribution of nettle (Urtica dioica) in Danish woodlands in relation to soil conditions (Olsen 1921). U. dioica was one of several plants which had been shown by Molisch (1883) to contain free nitrate in its tissues and this was confirmed by Olsen, who also showed that in sites where nettle colonies were adjacent to vegetation dominated by Deschampsia caespitosa, little or no nitrate could be detected in the leaves of the grass. Using an incubation technique, Olsen demonstrated this difference to be related to the intensity of nitrification in the respective soils, but where Urtica grew luxuriantly there was not only high nitrification, but also a high concentration of most plant nutrients including for example, calcium, magnesium, phosphate and in most cases potassium. Olsen also investigated the growth of Urtica in water culture and demonstrated that the species responds over a wide range to increases in nitrogen supply. In these experiments there was no comparison with the response of such species as Deschampsia caespitosa, so that the claim that Urtica dioica has an unusually high nitrogen requirement may seem unjustified. In spite of this criticism, the conclusion that the natural distribution of U. dioica is primarily controlled by nitrogen supply has found wide acceptance. The distribution of U. dioica in Britain has been summarized by Greig-Smith (1948). The species is widespread on disturbed soils around human habitations, farm buildings and at the foot of walls and hedges, especially along roadsides. It is also frequent in many types of woodland and grows luxuriantly in woods of Alnus glutinosa on alluvial soils and in woods of Fraxinus excelsior and Ulmus glabra in the north and west of Britain. In the limestone dales of the Pennines, Urtica dioica is one of several tall perennial herbaceous species which commonly occur together and form the characteristic vegetation along the foot of cliffs and screes, and on moist ungrazed ledges. In many of the wooded Derbyshire dales, this vegetation of tall herbs occurs in a narrow and discontinuous belt on deep mull along the foot of scree slopes, where the whole of the upper part of the scree is occupied by an almost continuous sward of Mercurialis perennis, or a mixture of this species with either Brachypodium silvaticum or Deschampsia caespitosa. This arrangement is illustrated in Fig. 1 by a transect in Monk's Dale, where a colluvial loam fills the bottom of the dale and is occupied by D. caespitosa. The composition of the three types of vegetation in comparable sites in Cressbrook Dale is summarized in Table 1. Both Urtica dioica and Mercurialis perennis are perennials, which die down in winter and produce a fresh crop of photosynthetic shoots each year. Deschampsia caespitosa
140 citations
TL;DR: In this article, the authors analyzed the thermal regime of the active layer at four sites with different vegetation (bare ground, lichen vegetation with Usnea aurantiaco-atra, moss vegetation with Sanionia uncinata, grass vegetation with Deschampsia antarctica) but with similar topographic and geomorphological conditions at Signy Island (Maritime Antarctica).
128 citations
TL;DR: Although the overall use of grass and heather by sheep and red deer was similar within this fragmented mosaic, vegetation pattern clearly affected their foraging behaviour differentially, suggesting that range overlap between these species may have much less of an impact on their vegetation use than previously assumed.
Abstract: 1. Heather moorland is an internationally important resource; it is valued as food and habitat for a range of herbivores as well as for landscape, conservation and recreation. In many parts of its range, grazing by large herbivores has impacted greatly on its current status and distribution. The interactions between two widespread herbivores, sheep and red deer, and the vegetation were examined within a naturally fragmented heather/grass mosaic in north-east Scotland from 1991 to 1996. This paper reports their foraging behaviour and inter-species interactions; and discusses the implications for grazing management within this vegetation type.
2. Both species foraged widely in this highly fragmented mosaic (red deer more widely than sheep) and consumed similar proportions of grass and heather. Neither species showed any major dietary shift as grass availability declined during experimental periods.
3. Grass patch size affected foraging behaviour differentially. Sheep spent more time grazing smaller grass patches (1-6 m²), whereas red deer showed no consistent grass patch size preferences (range: 1 m² to over 200 m²). When lying down, red deer lay within heather almost exclusively, whereas sheep spent equal amounts of time within heather and small grass patches.
4. Faecal distribution also differed in a similar way, with concomitant implications for the spatial distribution of both physical and chemical impacts on the vegetation.
5. Contrary to previous hypotheses, the overall patterns of foraging behaviour by sheep and deer were little affected by the presence or absence of the other species. This suggests that range overlap between these species may have much less of an impact on their vegetation use than previously assumed.
6. Heather moorland is frequently found on sloping ground, which was shown to have a major effect on foraging, with a strong preference by both species for grazing facing either uphill or across the slope. This, and other slope-related impacts, resulted in spatially different patterns of heather use around the edges of grass patches.
7. The primary conclusions are that, although the overall use of grass and heather by sheep and red deer was similar within this fragmented mosaic, vegetation pattern clearly affected their foraging behaviour differentially. Sheep appeared to be much more affected by the scale of heather fragmentation than were deer and their habitat use was more closely focused on paths and grass patches, which contrasts with the more even use of the mosaic by deer. The implications of these behavioural differences for the management of upland grazings under one or both of these herbivore species are discussed.
121 citations
TL;DR: In a perennial grassland undergoing succession after the removal of domestic grazers, three natural processes could disrupt the canopy, and thus affect colonization, and the best colonizers were Anthoxanthum and Holcus, whose colonization success was increased 6-2500-fold by canopy gap formation, and 10-200-foldBy the formation of gopher mounds.
Abstract: SUMMARY (1) In a perennial grassland undergoing succession after the removal of domestic grazers, three natural processes could disrupt the canopy, and thus affect colonization. These are: canopy gap formation due to the death of individual bunchgrasses; soil disturbance by gophers; and grazing by native animals. (2) Species' abilities to colonize canopy gaps and gopher mounds were assessed in the field, with seed introduction experiments, for the five most cover-dominant grass species: Anthoxanthum odoratum, Holcus lanatus, Deschampsia holciformis, Rytidosperma pilosum (all perennial bunchgrasses) and Vulpia bromoides (an annual grass). (3) The effects of native grazers on colonization by the most abundant species, Anthoxanthum, were assessed, using grazer exclosures and seed introductions in annualdominated vegetation, where grazing activity was highest. (4) Colonization success was quantified as total leaf area, number of survivors and seed production, in sites where seeds of the colonist either fell naturally, or were introduced at natural densities. (5) The formation of canopy gaps by the death of individual bunchgrasses and soil disturbances by gophers strongly affected colonization success. The best colonizers were Anthoxanthum and Holcus, whose colonization success was increased 6-2500-fold by canopy gap formation, and 10-200-fold by the formation of gopher mounds. Few, small seedlings of Deschampsia and Rytidosperma survived in canopy gaps or on gopher mounds. Unlike Anthoxanthum and Holcus, Deschampsia and Rytidosperma did not reproduce in gaps or on mounds over a two-year period. (6) Vulpia colonists had higher seed production on mounds than the four perennials. Vulpia also colonized canopy gaps, but was excluded by perennial vegetation in the second year of growth in the gaps. (7) In annual-dominated vegetation, neither aboveground biomass nor colonization by Anthoxanthum was affected by excluding grazers. However, exclusion of grazers led to an increase in the cover of forbs after two years. Clipping aboveground vegetation allowed Rytidosperma to achieve dominance in sites where, under undisturbed conditions, it existed only as a suppressed understorey. All other perennials were negatively affected by clipping. (8) The species with the highest natural densities of seed rain also had the greatest perseed colonization success, even though negative density-dependent effects must have been
111 citations
TL;DR: Results indicate that phenolics in Acomastylis are a C source for soil microorganisms, rather than an inhibitor of microbial activity, and influences soil N cycling by increasing microbial activity and N immobilization, which may influence N supply to neighboring plants.
Abstract: We measured the litter chemistry of two co-dominant alpine species, Acomastylis rossii, a forb characterized by a low growth rate and N uptake capacity, and Deschampsia caespitosa, a grass characterized by a high growth rate and N uptake capacity, and examined the effect litter of these two species had on the growth of Deschampsia phytometers in a greenhouse. We also examined the influence of litter from the two species on microbial respiration and immobilization of N, in two separate laboratory microcosm experiments and in the field. We hypothesized that Acomastylis litter would reduce plant growth more than Deschampsia litter, corresponding with either 1) suppression of microbial activity and thus a decrease in N mineralization, or 2) by stimulation of microbial biomass and increasing microbial immobilization of N. Relative to Deschampsia litter, Acomastylis litter had higher total water soluble organic carbon (DOC), and higher total phenolic concentration. Deschampsia litter had 30 times higher carbohydrate (primarily glucose and fructose) concentrations than Acomastylis litter. Soil respiration, microbial biomass N, and consumption of DOC and N were higher with the Acomastylis litter treatment than the Deschampsia litter treatment in experimental microcosms, and both respiration and microbial biomass N were higher in field soils under canopies dominated by Acomastylis relative to those dominated by Deschampsia. These results indicate that phenolics in Acomastylis are a C source for soil microorganisms, rather than an inhibitor of microbial activity. Deschampsia phytometers grew significantly less, had higher root: shoot biomass ratios, and acquired less nitrogen in the Acomastylis litter treatment relative to the control and Deschampsia litter treatments. The results of these experiments indicate that Acomastylis litter influences soil N cycling by increasing microbial activity and N immobilization, which may influence N supply to neighboring plants. This mechanism has the potential to influence competitive interactions between Acomastylis and its neighbors.
83 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2020 | 3 |
| 2019 | 3 |
| 2018 | 4 |
| 2017 | 5 |
| 2016 | 5 |