scholarly journals Living at the Edge: Increasing Stress for Plants 2–13 Years After the Retreat of a Tropical Glacier

2021 ◽  
Vol 9 ◽  
Author(s):  
Fabien Anthelme ◽  
Sophie Cauvy-Fraunié ◽  
Bernard Francou ◽  
Bolívar Cáceres ◽  
Olivier Dangles
Keyword(s):  
Species Richness ◽  
Abiotic Stress ◽  
Plant Diversity ◽  
Plant Succession ◽  
Positive Interactions ◽  
Plant Colonization ◽  
Tropical Andes ◽  
Glacial Retreat ◽  
Distribution Study ◽  
Grain Distribution

Rapid warming is a major threat for the alpine biodiversity but, at the same time, accelerated glacial retreat constitutes an opportunity for taxa and communities to escape range contraction or extinction. We explored the first steps of plant primary succession after accelerated glacial retreat under the assumption that the first few years are critical for the success of plant establishment. To this end, we examined plant succession along a very short post-glacial chronosequence in the tropical Andes of Ecuador (2–13 years after glacial retreat). We recorded the location of all plant individuals within an area of 4,200 m2 divided into plots of 1 m2. This sampling made it possible to measure the responses of the microenvironment, plant diversity and plants traits to time since the glacial retreat. It also made it possible to produce species-area curves and to estimate positive interactions between species. Decreases in soil temperature, soil moisture, and soil macronutrients revealed increasing abiotic stress for plants between two and 13 years after glacial retreat. This increasing stress seemingly explained the lack of positive correlation between plant diversity and time since the glacial retreat. It might explain the decreasing performance of plants at both the population (lower plant height) and the community levels (lower species richness and lower accumulation of species per area). Meanwhile, infrequent spatial associations among plants indicated a facilitation deficit and animal-dispersed plants were almost absent. Although the presence of 21 species on such a small sampled area seven years after glacial retreat could look like a colonization success in the first place, the increasing abiotic stress may partly erase this success, reducing species richness to 13 species after 13 years and increasing the frequency of patches without vegetation. This fine-grain distribution study sheds new light on nature's responses to the effects of climate change in cold biomes, suggesting that faster glacial retreat would not necessarily result in accelerated plant colonization. Results are exploratory and require site replications for generalization.

Temperature and vegetation complexity structure mixed-species flocks along a gradient of elevation in the tropical Andes

The Auk ◽  
2021 ◽  
Author(s):  
Flavia A Montaño-Centellas ◽  
Harrison H Jones
Keyword(s):  
Species Richness ◽  
Abiotic Stress ◽  
Environmental Gradients ◽  
Bird Community ◽  
Taxonomic Diversity ◽  
High Elevation ◽  
Tropical Andes ◽  
Mixed Species ◽  
Mixed Species Flocks ◽  
Species Flocks

Abstract Mixed-species flocks constitute community modules that can help test mechanisms driving changes to community composition across environmental gradients. Here, we examined elevational patterns of flock diversity (species richness, taxonomic diversity, species, and guild composition) and asked if these patterns were reflections of the full bird community at a given elevation (open-membership hypothesis), or if they were instead structured by environmental variables. We surveyed both the overall avian community and mixed-species flocks across an undisturbed elevational gradient (~1,350–3,550 m) in the Bolivian Andes. We then tested for the role of temperature (a surrogate for abiotic stress), resource diversity (arthropods, fruits), and foraging niche diversity (vegetation vertical complexity) in structuring these patterns. Patterns for the overall and flocking communities were similar, supporting our open-membership hypothesis that Andean flocks represent dynamic, unstructured aggregations. Membership openness and the resulting flock composition, however, also varied with elevation in response to temperature and vegetation complexity. We found a mid-elevation peak in flock species richness, size, and Shannon’s diversity at ~2,300 m. The transition of flocking behavior toward a more open-membership system at this elevation may explain a similar peak in the proportion of insectivores joining flocks. At high elevations, increasing abiotic stress and decreasing fruit diversity led more generalist, gregarious tanagers (Thraupidae) to join flocks, resulting in larger yet more even flocks alongside a loss of vegetation structure. At lower elevations, flock species richness increased with greater vegetation complexity, but a greater diversity of foraging niches resulted in flocks that were more segregated into separate canopy and understory sub-types. This segregation likely results from increased costs of interspecific competition and activity matching (i.e., constraints on movement and foraging rate) for insectivores. Mid-elevation flocks (~2,300 m) seemed, therefore, to benefit from both the open-membership composition of high-elevation flocks and the high vegetation complexity of mid- and low-elevation forests.

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.

Plant diversity and species richness of Ljubljana marsh grasslands under the influence of different cutting and fertilizing regimes

2009 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
T. Sinkovč
Keyword(s):  
Species Richness ◽  
Plant Diversity ◽  
Grassland Management ◽  
Botanical Composition ◽  
Significant Negative Effect ◽  
Negative Effect ◽  
Cutting Regimes ◽  
N Rates ◽  
Exploitation Intensity ◽  
Plot Design

The botanical composition of grasslands determines the agronomic and natural values of swards. Good grassland management usually improves herbage value, but on the other hand it frequently decreases the plant diversity and species richness in the swards. In 1999 a field trial in a split-plot design with four replicates was therefore established on the Arrhenatherion type of vegetation in Ljubljana marsh meadows in order to investigate this relationship. Cutting regimes (2 cuts — with normal and delayed first cut, 3 cuts and 4 cuts per year) were allocated to the main plots and fertiliser treatments (zero fertiliser — control, PK and NPK with 2 or 3 N rates) were allocated to the sub-plots. The results at the 1 st cutting in the 5 th trial year were as follows: Fertilising either with PK or NPK had no significant negative effect on plant diversity in any of the cutting regimes. In most treatments the plant number even increased slightly compared to the control. On average, 20 species were listed on both unfertilised and fertilised swards. At this low to moderate level of exploitation intensity, the increased number of cuts had no significant negative effect on plant diversity either (19 species at 2 cuts vs. 20 species at 3 or 4 cuts). PK fertilisation increased the proportion of legumes in the herbage in the case of 2 or 3 cuts. The proportion of grasses in the herbage increased in all the fertilisation treatments with an increased numbers of cuts. Fertiliser treatment considerably reduced the proportion of marsh horsetail ( Equisetum palustre ) in the herbage of the meadows. This effect was even more pronounced at higher cut numbers. The proportion of Equisetum palustre in the herbage was the highest in the unfertilised sward with 2 cuts (26.4 %) and the lowest in the NPK-fertilised sward with 4 cuts (1.4%).

scholarly journals Biodiversity hanging by a thread: the importance of fungal litter-trapping systems in tropical rainforests

2011 ◽  
Vol 8 (3) ◽  
pp. 397-400 ◽  
Author(s):  
Jake L. Snaddon ◽  
Edgar C. Turner ◽  
Tom M. Fayle ◽  
Chey V. Khen ◽  
Paul Eggleton ◽  
...  
Keyword(s):  
Species Richness ◽  
Leaf Litter ◽  
Plant Diversity ◽  
Habitat Complexity ◽  
Tropical Rainforests ◽  
Dramatic Reduction ◽  
Experimental Removal ◽  
Crucial Component ◽  
High Species Richness ◽  
Vital Resource

The exceptionally high species richness of arthropods in tropical rainforests hinges on the complexity of the forest itself: that is, on features such as the high plant diversity, the layered nature of the canopy and the abundance and the diversity of epiphytes and litter. We here report on one important, but almost completely neglected, piece of this complex jigsaw—the intricate network of rhizomorph-forming fungi that ramify through the vegetation of the lower canopy and intercept falling leaf litter. We show that this litter-trapping network is abundant and intercepts substantial amounts of litter (257.3 kg ha −1 ): this exceeds the amount of material recorded in any other rainforest litter-trapping system. Experimental removal of this fungal network resulted in a dramatic reduction in both the abundance (decreased by 70.2 ± 4.1%) and morphospecies richness (decreased by 57.4 ± 5.1%) of arthropods. Since the lower canopy levels can contain the highest densities of arthropods, the proportion of the rainforest fauna dependent on the fungal networks is likely to be substantial. Fungal litter-trapping systems are therefore a crucial component of habitat complexity, providing a vital resource that contributes significantly to rainforest biodiversity.

scholarly journals Convergence of soil microbial properties after plant colonization of an experimental plant diversity gradient

BMC Ecology ◽  
2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Katja Steinauer ◽  
Britta Jensen ◽  
Tanja Strecker ◽  
Enrica de Luca ◽  
Stefan Scheu ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Plant Colonization ◽  
Experimental Plant ◽  
Microbial Properties ◽  
Soil Microbial ◽  
Diversity Gradient ◽  
Soil Microbial Properties

scholarly journals Relationship between moth (night active Lepidoptera) diversity and vegetation characteristics in southern Sweden

2020 ◽  
Vol 24 (6) ◽  
pp. 1005-1015
Author(s):  
Torbjörn Tyler
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Plant Diversity ◽  
Vascular Plant ◽  
Habitat Characteristics ◽  
Vegetation Composition ◽  
Vascular Plant Diversity ◽  
Site Characteristics ◽  
Tree Canopy Cover ◽  
Wide Range

Abstract The diversity and community composition of moths (both macro- and micromoths) at 32 sites, representing a wide range of habitat types (forests, grasslands, wetlands, agricultural and urban areas) within a restricted region in central Scania, southern-most Sweden, was investigated by use of light moth traps and compared with vascular plant species richness and habitat characteristics. The results revealed a highly significant general association between vegetation composition and the composition of the moth community and multivariate (CCA) analyses indicated light availability and soil fertility parameters (pH and macronutrients) to be the habitat characteristics that best correlated with moth community composition. Less strong, but still significant, positive relationships between moth abundance and local vascular plant diversity were also revealed. Moth species richness was positively correlated with diversity of woody plant genera in the neighborhood, but not with local vascular plant diversity in general. As for more general site characteristics, there were tendencies for higher moth richness and abundance at sites with more productive soils (well-drained, high pH, high nutrient availability), while shading/tree canopy cover, management, soil disturbance regimes and nectar production appeared unrelated to moth community parameters. It is concluded that local moth assemblages are strongly influenced by site characteristics and vegetation composition. Implications for insect conservation: The results show that obtaining moth data on a local scale is useful for conservation planning and does not need to be very cumbersome. Local moth assemblages monitored are indeed related to local site characteristics of conservation relevance.

scholarly journals Superhost Plants Alter the Structure of Plant–Galling Insect Networks in Neotropical Savannas

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 369 ◽  
Author(s):  
Araújo ◽  
Moreira ◽  
Falcão ◽  
Borges ◽  
Fagundes ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Diversity ◽  
Host Plants ◽  
Plant Species Richness ◽  
Variable Number ◽  
Insect Species ◽  
Species Number ◽  
Neotropical Savannas ◽  
Galling Insects

Host plants may harbor a variable number of galling insect species, with some species being able to harbor a high diversity of these insects, being therefore called superhost plants. In the present study, we tested the hypothesis that the occurrence of superhost plant species of genus Qualea (Vochysiaceae) affects the structure of plant–galling insect ecological networks in Brazilian Cerrado. We sampled a total of 1882 plants grouped in 131 species and 43 families, of which 64 species and 31 families of host plants hosted 112 galling insect species. Our results showed that occurrence of superhosts of genus Qualea increased the linkage density of plant species, number of observed interactions, and the size of plant–galling insect networks and negatively affected the network connectance (but had no effect on the residual connectance). Although the occurrence of Qualea species did not affect the plant species richness, these superhosts increased the species richness and the number of interactions of galling insects. Our study represents a step forward in relation to previous studies that investigated the effects of plant diversity on the plant–insect networks, showing that few superhost plant species alter the structure of plant–herbivore networks, even without having a significant effect on plant diversity.

Progressive glacial retreat in the Southern Altiplano (Uturuncu volcano, 22°S) between 65 and 14 ka constrained by cosmogenic 3He dating

2014 ◽  
Vol 82 (1) ◽  
pp. 209-221 ◽  
Author(s):  
Pierre-Henri Blard ◽  
Jérôme Lave ◽  
Kenneth A. Farley ◽  
Victor Ramirez ◽  
Nestor Jimenez ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Late Glacial ◽  
Glacial Period ◽  
Tropical Andes ◽  
Equilibrium Line Altitude ◽  
Glacial Retreat ◽  
Late Glacial Period ◽  
Cold Episode ◽  
Glacial Landforms ◽  
Exposure Ages

AbstractThis work presents the first reconstruction of late Pleistocene glacier fluctuations on Uturuncu volcano, in the Southern Tropical Andes. Cosmogenic 3He dating of glacial landforms provides constraints on ancient glacier position between 65 and 14 ka. Despite important scatter in the exposure ages on the oldest moraines, probably resulting from pre-exposure, these 3He data constrain the timing of the moraine deposits and subsequent glacier recessions: the Uturuncu glacier may have reached its maximum extent much before the global LGM, maybe as early as 65 ka, with an equilibrium line altitude (ELA) at 5280 m. Then, the glacier remained close to its maximum position, with a main stillstand identified around 40 ka, and another one between 35 and 17 ka, followed by a limited recession at 17 ka. Then, another glacial stillstand is identified upstream during the late glacial period, probably between 16 and 14 ka, with an ELA standing at 5350 m. This stillstand is synchronous with the paleolake Tauca highstand. This result indicates that this regionally wet and cold episode, during the Heinrich 1 event, also impacted the Southern Altiplano. The ELA rose above 5450 m after 14 ka, synchronously with the Bolling–Allerod.

scholarly journals Response of pollen diversity to the climate-driven altitudinal shift of vegetation in the Colombian Andes

2006 ◽  
Vol 362 (1478) ◽  
pp. 253-262 ◽  
Author(s):  
Chengyu Weng ◽  
Henry Hooghiemstra ◽  
Joost F Duivenvoorden
Keyword(s):  
Plant Diversity ◽  
Climatic Conditions ◽  
Fossil Pollen ◽  
Tropical Andes ◽  
Lower Altitude ◽  
The Past ◽  
Colombian Andes ◽  
Altitudinal Shift ◽  
Study Sites ◽  
The Relationship

Change in diversity of fossil pollen through time is used as a surrogate for biodiversity history. However, there have been few studies to explore the sensitivity of the measured pollen diversity to vegetation changes and the relationship between pollen diversity and plant diversity. This paper presents results of a study to assess the relationship between pollen diversity and relative abundance of pollen from different altitudinal vegetation belts (subandean forest, Andean forest, subparamo and grassparamo) in three records from the tropical Andes in Colombia. The results indicated that plant diversity in the vegetation declined with altitude and pollen diversity is positively correlated to the abundance of pollen from lower altitude vegetation belts and negatively correlated to that from the grassparamo. These results, therefore, suggest that pollen diversity coarsely reflects the diversity of the surrounding vegetation. Using this interpretation, we were able to predict changes in plant diversity over the past 430 000 years in the Colombian Andes. Results indicated that under warmer climatic conditions, more species-diverse vegetation of low elevation moved upslope to contribute more pollen diversity to the study sites, and under colder conditions, species-poor grassparamo moved downslope and observed pollen diversity was lower. This study concludes that fossil pollen diversity may provide an important proxy to reconstruct the temporal changes in plant diversity.

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