scholarly journals Seabirds and seals as drivers of plant succession on Surtsey

2020 ◽  
Vol 14 ◽  
pp. 115-130
Author(s):  
Borgthór Magnússon ◽  
Gudmundur A. Gudmundsson ◽  
Sigmar Metúsalemsson ◽  
Sandra M. Granquist
Keyword(s):  
Plant Cover ◽  
Plant Succession ◽  
Present Species ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Grey Seal ◽  
Breeding Area ◽  
Vegetation Development ◽  
Dense Patch ◽  
First Time

Plant colonization and succession on Surtsey have been monitored since 1965. In 2019, the 75th species of vascular plants was detected on the island, 62 species were present and about 40 species had established viable populations. Over the last decade colonization has slowed down and the number of present species not increased. The rising number of seagulls breeding on the island after 1985 had a great impact on plant colonization and vegetation development. While most parts of the island remained barren, a grassland area (13 ha in 2018) developed in the main seagull breeding colony on the southern part of the island. This development is attributed to transfer of nutrients from sea to land by the seagulls. In recent years a dense patch of vegetation, 2 ha in 2018, has also developed on the low, northern spit of the island, where a few pairs of seagulls breed in the spring and grey seals haul out and breed in the fall in considerable numbers. In a survey conducted during the grey seal pupping period in 2019, the seal abundance and spatial distribution was mapped accurately for the first time. The results show that the dense vegetation of the spit and seal distribution are clearly overlapping. The continuous shrinking of the island and its spit has led to an increasing concentration of the seals in their breeding area. Based on a literature survey we estimated the nitrogen (N) input from sea to land by the grey seals as 9-13 kg N/ha in 2019. This compares to an estimated input of 5-30 kg N/ha/yr by the seagulls breeding in the same area during 2015-2019. Within the grey seal and seagull breeding area on the spit of the island, a distinct community of shore plants has developed. Measurements of plant cover and biomass in permanent plots on Surtsey in 2018 and 2019 show that development on part of the spit is reaching a similar state as in the old gull colony on the southern part of the island. This suggests that the grey seals along with the seagulls are important drivers of plant succession on the northern spit. Further research on the effects of the seals on nutrient transfer from sea to land and ecosystem development on Surtsey is recommended.

scholarly journals Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

2014 ◽  
Vol 11 (19) ◽  
pp. 5521-5537 ◽  
Author(s):  
B. Magnússon ◽  
S. H. Magnússon ◽  
E. Ólafsson ◽  
B. D. Sigurdsson
Keyword(s):  
Species Richness ◽  
Plant Biomass ◽  
Vascular Plant ◽  
Plant Cover ◽  
Soil Formation ◽  
Plant Succession ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Nutrient Input ◽  
Species Richness And Diversity

Abstract. Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca/Agrostis/Ranunculus). We forecast that, with continued erosion of Surtsey, loss of habitats and increasing impact from seabirds a lush, species-poor grassland will develop and persist, as on the old neighbouring islands.

scholarly journals Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

2014 ◽  
Vol 11 (6) ◽  
pp. 9379-9420 ◽  
Author(s):  
B. Magnússon ◽  
S. H. Magnússon ◽  
E. Ólafsson ◽  
B. D. Sigurdsson
Keyword(s):  
Species Richness ◽  
Plant Biomass ◽  
Vascular Plant ◽  
Plant Cover ◽  
Soil Formation ◽  
Plant Succession ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Nutrient Input ◽  
Species Richness And Diversity

Abstract. Plant colonization and succession on Surtsey volcanic island, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands and all their common species had established on Surtsey. The first colonizers were dispersed by sea, but after 1985 bird-dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007 there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliðaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliðaey was very dense and species-poor. Dominated by Festuca and Poa, it it was very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca/Agrostis/Ranunculus). We forecast that with continued erosion of Surtsey, loss of habitats and increasing impact from seabirds a lush, species poor grassland will develop and persist, as on the old neighbouring islands.

scholarly journals Impacts of Geomorphic Disturbances on Plant Colonization in Ebba Valley, Central Spitsbergen, Svalbard

2017 ◽  
Vol 36 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Monika Stawska
Keyword(s):  
Marginal Zone ◽  
Plant Cover ◽  
Climatic Conditions ◽  
Plant Colonization ◽  
Polar Regions ◽  
Vegetation Development ◽  
Plant Coverage ◽  
Vegetation Sampling ◽  
Marine Terraces ◽  
Main Factors

Abstract Global warming observed nowadays causes an increase in geomorphic activity in polar regions. Within the areas influenced by cold climatic conditions, relief dynamics and vegetation development are the main landscape shaping processes. The study is limited to the Ebba Valley (78°43’N; 16°37’E) in central Spitsbergen (Svalbard), where geomorphologic observations and vegetation sampling were conducted in 2007. The valley was divided into three zones differentiated by dominating geomorphic activity and stability of deposits. The settlement and the evolution of plant cover have been documented there. The main factors that control well developed vegetation cover within raised marine terraces are frost heave and solifluction. In deeper parts of the valley, aeolian processes dominate and high differentiation of microsite conditions causes high variability in plant coverage. The area close to the Ebba glacier marginal zone is characterized by initial stages of plant colonisation where disturbance to vegetation is mainly caused by hydrological processes.

scholarly journals Statistical assessment of ecological invariants of plant cover and the possibility of estimating invariants in the taxonomy of plants

2021 ◽  
Vol 20 (1) ◽  
pp. 401-403
Author(s):  
B. I. Semkin ◽  
L. I. Varchenko
Keyword(s):  
Statistical Methods ◽  
Plant Cover ◽  
Leningrad Region ◽  
Statistical Assessment ◽  
Biological Objects ◽  
First Time

In this work, for the first time, ecological invariants for the dry polydominant cereal-forb meadow of theKarelian Isthmus of the Leningrad region and taxonomic invariants of three species of Heracleum L. are determined. It isproposed to use the developed statistical methods for evaluating invariants to differentiate biological objects at all levels ofbiota: molecular, subcellular, cellular, organismic, population, coenotic and ecological.

scholarly journals Local changes in communities of wild bees (Hymenoptera: Apoidea, Apiformes): 30 years later

2014 ◽  
Vol 83 (4) ◽  
pp. 325-351 ◽  
Author(s):  
Józef Banaszak ◽  
Halina Ratyńska
Keyword(s):  
Agricultural Landscape ◽  
Plant Succession ◽  
Permanent Plots ◽  
Wild Bees ◽  
Natural Habitats ◽  
Increasing Trend ◽  
Quantitative Changes ◽  
Abundance And Diversity ◽  
Bee Communities ◽  
Forest Habitats

ABSTRACT Changes in communities of wild bees (Apiformes) were studied in relation to changes in vegetation in six permanent plots (natural forest habitats in the Wielkopolska National Park, and semi-natural habitats in the agricultural landscape near Turew) at the end of four decades (starting from the late 1970s). In 2008-2010, as many as 100 species of Apiformes were recorded there, which is more than reported in earlier decades. The most stable bee communities were those in forest habitats (oak-hornbeam forest, oak forest). Substantial qualitative and quantitative changes in vegetation and bee communities were recorded only after the renaturalisation of a former xerothermic grassland, which had become overgrown with shrubs and trees as a result of plant succession. Human interference (e.g. the felling of some trees growing along a road, clearance of understorey shrubs, ploughing of roadside margins) at selected refuge habitats in the agricultural landscape led to short-term fluctuations in bee abundance and diversity, but an increasing trend in abundance was noted.

scholarly journals Spatiotemporal Degradation of Abandoned Farmland and Associated Eco-Environmental Risks in the High Mountains of the Nepalese Himalayas

Land ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Suresh Chaudhary ◽  
Yukuan Wang ◽  
Amod Mani Dixit ◽  
Narendra Raj Khanal ◽  
Pei Xu ◽  
...  
Keyword(s):  
Local Level ◽  
Google Earth ◽  
Environmental Risks ◽  
Plant Succession ◽  
Plant Colonization ◽  
Negative Effects ◽  
Rock Falls ◽  
Farmland Abandonment ◽  
Abandoned Farmland ◽  
Aerial Vehicle

Globally, farmland abandonment has been a major phenomenon for eco-environmental and social landscape changes in the mountain regions. Farmland abandonment led to endangering the capacity of mountain ecosystems as well as variety of eco-environmental processes that play a pivotal role in regional as well local level eco-environment security. This research aims to (i) assess the spatiotemporal degradation of abandoned farmlands, (ii) identify the major causes of farmland degradation, and (iii) analyze the eco-environmental risks triggered or exacerbated by the degradation of abandoned farmlands. We conducted an inventory of the spatiotemporal distribution of abandoned farmlands and their degradation status with Google earth images and by modeling and interpreting low-height remote sensing images taken by an unmanned aerial vehicle (UAV). Geomorphic damages were mapped at the scale of individual abandoned farms. A multivariate regression statistical (MRS) model was used to identify the major causes of degradation. This research revealed that out of the total surveyed farmlands, 92% were already completely irreversibly damaged. The damages started with the disruption of terraces and bulging processes that occurred within the year after abandonment. This degradation induced diverse hazardous processes, such as landslides, debris flows, rock falls, the formation of gullies, soil erosion, and the development of sinkholes, which increase the negative effects of on both land resources and plant succession. Farmland abandonment does not automatically lead to plant colonization because geomorphic damage is intensified prior to colonization. Therefore, land management is required for plant colonization as well as other efforts to reduce degradation induced eco-environmental risk. This study thus could help land planners and environmentalists in the development of suitable guidelines (pre- or post-abandonment) plans, programmes, and legislation to effectively address the problem of abandoned farmland.

Ecological Characteristics of Sites Invaded by Buffelgrass (Pennisetum ciliare)

2012 ◽  
Vol 5 (4) ◽  
pp. 443-453 ◽  
Author(s):  
Scott R. Abella ◽  
Lindsay P. Chiquoine ◽  
Dana M. Backer
Keyword(s):  
Seed Bank ◽  
Sonoran Desert ◽  
Native Species ◽  
Plant Cover ◽  
The United States ◽  
Slope Aspect ◽  
Plant Colonization ◽  
Native Plant ◽  
Organic C ◽  
Ecological Characteristics

AbstractUnderstanding the ecological characteristics of areas invaded and not invaded by exotic plants is a priority for invasive plant science and management. Buffelgrass is an invasive perennial species that managers view as a major threat to indigenous ecosystems of conservation lands in Australia, Mexico, the United States, and other locations where the species is not native. At 14 sites in Saguaro National Park in the Arizona Uplands of the Sonoran Desert, we compared the soil, vegetation, and soil seed bank of patches invaded and not invaded by buffelgrass. Abiotic variables, such as slope aspect and soil texture, did not differ between buffelgrass patches and patches without buffelgrass. In contrast, variables under primarily biotic control differed between patch types. Soil nutrients, such as organic C and NO3–N, were approximately twofold greater in buffelgrass compared with nonbuffelgrass patches. Average native species richness was identical (14 species 100 m−2) between patch types, but native plant cover was 43% lower in buffelgrass patches. Unexpectedly, native seed-bank densities did not differ significantly between patch types and were 40% greater than buffelgrass seed density below buffelgrass canopies. Results suggest that (1) soil nutrient status should not be unfavorable for native plant colonization at buffelgrass sites if buffelgrass is treated; (2) at least in the early stages of buffelgrass patch formation (studied patches were about 10 yr old), native vegetation species were not excluded, but rather, their cover was reduced; and (3) native soil seed banks were not reduced in buffelgrass patches.

scholarly journals Macrofungi of Aceri-Tilietum and Tilio-Carpinetum in the „Dolina Rzeki Brdy” nature reserve in the Bory Tucholskie (NW Poland)

2014 ◽  
Vol 37 (1-2) ◽  
pp. 63-76
Author(s):  
Maria Ławrynowicz ◽  
Tomasz Dziedziński ◽  
Jarosław Szkodzik
Keyword(s):  
Nature Reserve ◽  
Permanent Plots ◽  
Lignicolous Fungi ◽  
Plant Associations ◽  
Diagnostic Role ◽  
First Time ◽  
Nw Poland

Mycocoenological studies on macrofungi in the <i>Tilio-Carpinetum</i> and <i>Aceri-Tilietum</i> plant associations were carried out in 4 permanent plots (1000 m<sup>2</sup> each) in the southern part of the "Dolina Rzeki Brdy" nature reserve. In 1994-1995, the total number of 279 species, mostly <i>Basidiomycotina</i>, were recorded. Mycological investigations of <i>Aceri-Tilietum</i> were conducted for the first time. The share of biological groups: terricolous, litter-inhabiting and lignicolous fungi as well as the diagnostic role of macromycetes in the investigated phytocoenoses, arelysed in the paper.

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