Generalism in the interaction of Tulasnellaceae mycobionts with orchids characterizes a biodiversity hotspot in the tropical Andes of Southern Ecuador

Mycoscience ◽  
2018 ◽  
Vol 59 (1) ◽  
pp. 38-48 ◽  
Author(s):  
Paulo Herrera ◽  
Ingrid Kottke ◽  
M. Carmen Molina ◽  
Marcos Méndez ◽  
Juan Pablo Suárez
Keyword(s):  
Biodiversity Hotspot ◽  
Tropical Andes ◽  
Southern Ecuador

scholarly journals Evolutionary persistence in Gunnera and the contribution of southern plant groups to the tropical Andes biodiversity hotspot

2017 ◽  
Author(s):  
Christine D. Bacon ◽  
Francisco Velásquez-Puentes ◽  
Luis Felipe Hinojosa ◽  
Thomas Schwartz ◽  
Bengt Oxelman ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Biodiversity Hotspot ◽  
Tropical Andes ◽  
Quaternary Climate ◽  
Biogeographic History ◽  
Plant Groups ◽  
History Of ◽  
Rapid Diversification ◽  
High Degree ◽  
Evolutionary Persistence

Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes – the world’s “hottest” biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e. páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera, a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby Gunnera tracks damp and boggy soils in cool habitats. Colonisation of the northern Andes is related to Quaternary climate change, with subsequent rapid diversification appearing to be driven by their ability to take advantage of environmental opportunities. This study demonstrates the composite origin of a mega-diverse biota.

scholarly journals Reasons for an outstanding plant diversity in the tropical Andes of Southern Ecuador

2009 ◽  
Vol 12 ◽  
pp. 1-35 ◽  
Author(s):  
Michael Richter ◽  
Karl-Heinz Diertl ◽  
Paul Emck ◽  
Thorsten Peters ◽  
Erwin Beck
Keyword(s):  
Human Impact ◽  
Plant Diversity ◽  
Vascular Plant ◽  
Global Scale ◽  
Mountain Range ◽  
Tropical Andes ◽  
Constant Input ◽  
General Role ◽  
Southern Ecuador ◽  
The Impact

Long-term field studies in the scope of a multidisciplinary project in southern Ecuador revealed extraordinary high species numbers of many organismic groups. This article discusses reasons for the outstanding vascular plant diversity using a hierarchical scale-oriented top-down approach (Grüninger 2005), from the global scale to the local microscale. The global scale explains general (paleo-) ecological factors valid for most parts of the humid tropics, addressing various hypotheses and theories, such as the "greater effective evolutionary time", constant input of "accidentals", the "seasonal variability hypothesis", the "intermediate disturbance hypothesis", and the impact of soil fertility. The macroscale focuses on the Andes in northwestern South America. The tropical Andes are characterised by many taxa of restricted range which is particularly true for the Amotape-Huancabamba region, i.e. the so called Andean Depression, which is effective as discrete phytogeographic transition as well as barrier zone. Interdigitation of northern and southern flora elements, habitat fragmentation, geological and landscape history, and a high speciation rate due to rapid genetic radiation of some taxa contribute to a high degree of diversification. The mesoscale deals with the special environmental features of the eastern mountain range, the Cordillera Real and surrounding areas in southern Ecuador. Various climatic characteristics, the orographic heterogeneity, the geologic and edaphic conditions as well as human impact are the most prominent factors augmenting plant species diversity. On microscale, prevailing regimes of disturbance and environmental stresses, the orographic basement, as well as the general role on the various mountain chains are considered. Here, micro-habitats e.g. niches for epiphytes, effects of micro-relief patterns, and successions after small-sized disturbance events are screened. Direct effects of human impact are addressed and a perspective of possible effects of climate change on plant diversity is presented.

scholarly journals Genetic characterization of fragmented populations of Cinchona officinalis L. (Rubiaceae), a threatened tree of the northern Andean cloud forests

2019 ◽  
Vol 15 (6) ◽  
Author(s):  
Augusta Cueva-Agila ◽  
Diego Vélez-Mora ◽  
Daniela Arias ◽  
Manuel Curto ◽  
Harald Meimberg ◽  
...  
Keyword(s):  
Tropical Andes ◽  
Cloud Forests ◽  
Fragmented Populations ◽  
Distance Analysis ◽  
Southern Ecuador ◽  
Nuclear Microsatellite ◽  
Genetic Bottlenecks ◽  
Priority Populations ◽  
Genetic Distance Analysis

AbstractCinchona officinalis L., a tree species endemic to the cloud forests of the northern Tropical Andes, has suffered from historical bark harvesting for extraction of antimalarial compounds and has also experienced recent demographic losses from high rates of deforestation. Most remnant populations are found in severely degraded habitat on the edges of pastures while a minority are protected in private reserves. The goals of our research were to assess the genetic diversities of fragmented populations of C. officinalis in the Loja province of southern Ecuador, characterize their phylogeographic distribution with respect to the region’s complex topography, and identify priority populations for conservation. Five nuclear microsatellite loci and the chloroplast rps16 intron were used to analyze six populations. Moderate levels of genetic diversity were found in all populations although the more remote southern population (Angashcola) had slightly higher heterozygosity and allelic richness. There were no indications of recent genetic bottlenecks although an rps16 intron haplotype was fixed in four populations. Genetic distance analysis based on microsatellite data placed the four easternmost populations in the same clade while the Angashcola population was the most divergent. Also, the most frequent rps16 intron haplotype in Angashcola was not found in any other population. Although each of the studied populations should be protected from further deforestation and agricultural expansion, the Angashcola population deserves highest conservation priority.

scholarly journals Landslide susceptibility near highways is increased by 1 order of magnitude in the Andes of southern Ecuador, Loja province

2015 ◽  
Vol 15 (1) ◽  
pp. 45-57 ◽  
Author(s):  
A. Brenning ◽  
M. Schwinn ◽  
A. P. Ruiz-Páez ◽  
J. Muenchow
Keyword(s):  
Landslide Susceptibility ◽  
Odds Ratio ◽  
Linear Models ◽  
Additive Models ◽  
Tropical Andes ◽  
Landslide Occurrence ◽  
The Andes ◽  
Road Effects ◽  
Southern Ecuador ◽  
Order Of Magnitude

Abstract. Mountain roads in developing countries are known to increase landslide occurrence due to often inadequate drainage systems and mechanical destabilization of hillslopes by undercutting and overloading. This study empirically investigates landslide initiation frequency along two paved interurban highways in the tropical Andes of southern Ecuador across different climatic regimes. Generalized additive models (GAM) and generalized linear models (GLM) were used to analyze the relationship between mapped landslide initiation points and distance to highway while accounting for topographic, climatic, and geological predictors as possible confounders. A spatial block bootstrap was used to obtain nonparametric confidence intervals for the odds ratio of landslide occurrence near the highways (25 m distance) compared to a 200 m distance. The estimated odds ratio was 18–21, with lower 95% confidence bounds >13 in all analyses. Spatial bootstrap estimation using the GAM supports the higher odds ratio estimate of 21.2 (95% confidence interval: 15.5–25.3). The highway-related effects were observed to fade at about 150 m distance. Road effects appear to be enhanced in geological units characterized by Holocene gravels and Laramide andesite/basalt. Overall, landslide susceptibility was found to be more than 1 order of magnitude higher in close proximity to paved interurban highways in the Andes of southern Ecuador.

scholarly journals Evolutionary persistence in Gunnera and the contribution of southern plant groups to the tropical Andes biodiversity hotspot

2017 ◽  
Author(s):  
Christine D. Bacon ◽  
Francisco Velásquez-Puentes ◽  
Luis Felipe Hinojosa ◽  
Thomas Schwartz ◽  
Bengt Oxelman ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Biodiversity Hotspot ◽  
Tropical Andes ◽  
Quaternary Climate ◽  
Biogeographic History ◽  
Plant Groups ◽  
History Of ◽  
Rapid Diversification ◽  
High Degree ◽  
Evolutionary Persistence

Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes – the world’s “hottest” biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e. páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera, a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby Gunnera tracks damp and boggy soils in cool habitats. Colonisation of the northern Andes is related to Quaternary climate change, with subsequent rapid diversification appearing to be driven by their ability to take advantage of environmental opportunities. This study demonstrates the composite origin of a mega-diverse biota.

scholarly journals Landslide susceptibility near highways is increased by one order of magnitude in the Andes of southern Ecuador, Loja province

2014 ◽  
Vol 2 (3) ◽  
pp. 1945-1975 ◽  
Author(s):  
A. Brenning ◽  
M. Schwinn ◽  
A. P. Ruiz-Páez ◽  
J. Muenchow
Keyword(s):  
Landslide Susceptibility ◽  
Odds Ratio ◽  
Linear Models ◽  
Additive Models ◽  
Tropical Andes ◽  
Landslide Occurrence ◽  
The Andes ◽  
Road Effects ◽  
Southern Ecuador ◽  
Order Of Magnitude

Abstract. Mountain roads in developing countries are known to increase landslide occurrence due to often inadequate drainage systems and mechanical destabilization of hillslopes by undercutting and overloading. This study empirically investigates landslide initiation frequency along two paved interurban highways in the tropical Andes of southern Ecuador across different climatic regimes. Generalized additive models (GAM) and generalized linear models (GLM) were used to analyze the relationship between mapped landslide initiation points and distance to highway while accounting for topographic, climatic and geological predictors as possible confounders. A spatial block bootstrap was used to obtain non-parametric confidence intervals for the odds ratio of landslide occurrence near the highways (25 m distance) compared to a 200 m distance. The estimated odds ratio was 18–21 with lower 95% confidence bounds > 13 in all analyses. Spatial bootstrap estimation using the GAM supports the higher odds ratio estimate of 21.2 (95% confidence interval: 15.5–25.3). The highway-related effects were observed to fade at about 150 m distance. Road effects appear to be enhanced in geological units characterized by Holocene gravels and Laramide andesite/basalt. Overall, landslide susceptibility was found to be more than one order of magnitude higher in close proximity to paved interurban highways in the Andes of southern Ecuador.

New records of Myxomycetes (Amoebozoa) from the tropical Andes

Phytotaxa ◽  
2021 ◽  
Vol 522 (3) ◽  
pp. 231-239
Author(s):  
ITALO TREVIÑO-ZEVALLOS ◽  
IVÁN GARCÍA-CUNCHILLOS ◽  
CARLOS LADO
Keyword(s):  
New Records ◽  
Life Cycles ◽  
Biodiversity Hotspot ◽  
Diverse Group ◽  
Fruiting Bodies ◽  
Tropical Andes ◽  
Peruvian Andes ◽  
The Third ◽  
The World ◽  
First Time

The Myxomycetes comprise a remarkably diverse group of organisms within Amoebozoa, with over 1000 species currently recognized. These organisms, at the end of their life cycles produce fruiting bodies which are the basis for their systematics. Despite being a biodiversity hotspot, the tropical Andes has a myxobiota that remains barely explored so far. In this study, we report the occurrence of three species inhabiting the highlands of the Peruvian Andes between 3000–5000 m.a.s.l. Arcyodes incarnata and Trichia mirabilis are reported for the first time in the Southern Hemisphere and the Neotropics, respectively, while Metatrichia floripara represents the third record in the world, previously only known from Rwanda and Brazil. Fruiting bodies of T. mirabilis were detected as already developed in the field, while the previous reports only included moist chamber culture-derived specimens. These results notably enlarge the geographical distribution of these species and highlight the interest of the tropical Andes, which remains a challenging region to explore and determine its whole myxobiota.

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