scholarly journals Evolutionary heritage shapes tree distributions along an Amazon-to-Andes elevation gradient

2020 ◽  
Author(s):  
Andy R. Griffiths ◽  
Miles R. Silman ◽  
William Farfán Rios ◽  
Kenneth J. Feeley ◽  
Karina García Cabrera ◽  
...  
Keyword(s):  
Census Data ◽  
Environmental Changes ◽  
Elevation Gradient ◽  
Cloud Base ◽  
Valuable Insight ◽  
Montane Forests ◽  
Peruvian Andes ◽  
Habitat Specialisation ◽  
Tropical Montane Forests ◽  
Highly Sensitive

ABSTRACTUnderstanding how evolutionary constraints shape the elevational distributions of tree lineages provides valuable insight into the future of tropical montane forests under global change. With narrow elevational ranges, high taxonomic turnover, frequent habitat specialisation, and exceptional levels of endemism, tropical montane forests and trees are predicted to be highly sensitive to environmental change. Using plot census data from a gradient traversing >3000 m in elevation on the Amazonian flank of the Peruvian Andes, we employ phylogenetic approaches to assess the influence of evolutionary heritage on distribution trends of trees at the genus level. We find that closely related lineages tend to occur at similar mean elevations, with sister genera pairs occurring a mean 254 m in elevation closer to each other than the mean elevational difference for all genera pairs. We also demonstrate phylogenetic clustering both above and below 1750 m a.s.l, corresponding roughly to the cloud-base ecotone. Belying these general trends, some lineages occur across many different elevations. However, these highly plastic lineages are not phylogenetically clustered. Overall, our findings suggest that tropical montane forests are home to unique tree lineage diversity, constrained by their evolutionary heritage and vulnerable to substantial losses under environmental changes, such as rising temperatures or an upward shift of the cloud base.

scholarly journals Evolutionary Diversity Peaks at Mid-Elevations Along an Amazon-to-Andes Elevation Gradient

2021 ◽  
Vol 9 ◽  
Author(s):  
Andy R. Griffiths ◽  
Miles R. Silman ◽  
William Farfan-Rios ◽  
Kenneth J. Feeley ◽  
Karina García Cabrera ◽  
...  
Keyword(s):  
Census Data ◽  
Elevation Gradient ◽  
Taxonomic Diversity ◽  
Elevation Gradients ◽  
Peruvian Andes ◽  
Diversity Patterns ◽  
Representing Tree ◽  
Tree Ferns ◽  
Diversity Gradients ◽  
Amazonian Lowlands

Elevation gradients present enigmatic diversity patterns, with trends often dependent on the dimension of diversity considered. However, focus is often on patterns of taxonomic diversity and interactions between diversity gradients and evolutionary factors, such as lineage age, are poorly understood. We combine forest census data with a genus level phylogeny representing tree ferns, gymnosperms, angiosperms, and an evolutionary depth of 382 million years, to investigate taxonomic and evolutionary diversity patterns across a long tropical montane forest elevation gradient on the Amazonian flank of the Peruvian Andes. We find that evolutionary diversity peaks at mid-elevations and contrasts with taxonomic richness, which is invariant from low to mid-elevation, but then decreases with elevation. We suggest that this trend interacts with variation in the evolutionary ages of lineages across elevation, with contrasting distribution trends between younger and older lineages. For example, while 53% of young lineages (originated by 10 million years ago) occur only below ∼1,750 m asl, just 13% of old lineages (originated by 110 million years ago) are restricted to below ∼1,750 m asl. Overall our results support an Environmental Crossroads hypothesis, whereby a mid-gradient mingling of distinct floras creates an evolutionary diversity in mid-elevation Andean forests that rivals that of the Amazonian lowlands.

scholarly journals Mind the gap – Part 1: Accurately locating warm marine boundary layer clouds and precipitation using spaceborne radars

2020 ◽  
Vol 13 (5) ◽  
pp. 2363-2379 ◽  
Author(s):  
Katia Lamer ◽  
Pavlos Kollias ◽  
Alessandro Battaglia ◽  
Simon Preval
Keyword(s):  
Boundary Layer ◽  
Cloud Cover ◽  
Marine Boundary Layer ◽  
Short Pulse ◽  
Pulse Mode ◽  
Cloud Base ◽  
Boundary Layer Clouds ◽  
Highly Sensitive ◽  
Eastern North Atlantic ◽  
Long Pulse

Abstract. Ground-based radar observations show that, over the eastern North Atlantic, 50 % of warm marine boundary layer (WMBL) hydrometeors occur below 1.2 km and have reflectivities of < −17 dBZ, thus making their detection from space susceptible to the extent of surface clutter and radar sensitivity. Surface clutter limits the ability of the CloudSat cloud profiling radar (CPR) to observe the true cloud base in ∼52 % of the cloudy columns it detects and true virga base in ∼80 %, meaning the CloudSat CPR often provides an incomplete view of even the clouds it does detect. Using forward simulations, we determine that a 250 m resolution radar would most accurately capture the boundaries of WMBL clouds and precipitation; that being said, because of sensitivity limitations, such a radar would suffer from cloud cover biases similar to those of the CloudSat CPR. Observations and forward simulations indicate that the CloudSat CPR fails to detect 29 %–43 % of the cloudy columns detected by ground-based sensors. Out of all configurations tested, the 7 dB more sensitive EarthCARE CPR performs best (only missing 9.0 % of cloudy columns) indicating that improving radar sensitivity is more important than decreasing the vertical extent of surface clutter for measuring cloud cover. However, because 50 % of WMBL systems are thinner than 400 m, they tend to be artificially stretched by long sensitive radar pulses, hence the EarthCARE CPR overestimation of cloud top height and hydrometeor fraction. Thus, it is recommended that the next generation of space-borne radars targeting WMBL science should operate interlaced pulse modes including both a highly sensitive long-pulse mode and a less sensitive but clutter-limiting short-pulse mode.

scholarly journals Height-diameter allometry and above ground biomass in tropical montane forests: Insights from the Albertine Rift in Africa

PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0179653 ◽  
Author(s):  
Gérard Imani ◽  
Faustin Boyemba ◽  
Simon Lewis ◽  
Nsharwasi Léon Nabahungu ◽  
Kim Calders ◽  
...  
Keyword(s):  
Above Ground Biomass ◽  
Montane Forests ◽  
Albertine Rift ◽  
Ground Biomass ◽  
Tropical Montane Forests

scholarly journals Variant responses of tree seedling to seasonal drought stress along an elevational transect in tropical montane forests

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaoyang Song ◽  
Jieqiong Li ◽  
Wenfu Zhang ◽  
Yong Tang ◽  
Zhenhua Sun ◽  
...  
Keyword(s):  
Drought Stress ◽  
Tree Seedling ◽  
Montane Forests ◽  
Seasonal Drought ◽  
Tropical Montane Forests ◽  
Elevational Transect

scholarly journals Bioluminescence dynamics in single germinating bacterial spores reveal metabolic heterogeneity

2020 ◽  
Vol 17 (170) ◽  
pp. 20200350
Author(s):  
Zak Frentz ◽  
Jonathan Dworkin
Keyword(s):  
Cell Fate ◽  
Quantitative Measurement ◽  
Environmental Changes ◽  
Reducing Power ◽  
Extreme Case ◽  
Bacterial Bioluminescence ◽  
Highly Sensitive ◽  
Germination Timing ◽  
Metabolic Heterogeneity ◽  
Spore Forming Bacteria

Spore-forming bacteria modulate their metabolic rate by over five orders of magnitude as they transition between dormant spores and vegetative cells and thus represent an extreme case of phenotypic variation. During environmental changes in nutrient availability, clonal populations of spore-forming bacteria exhibit individual differences in cell fate, the timing of phenotypic transitions and gene expression. One potential source of this variability is metabolic heterogeneity, but this has not yet been measured, as existing single-cell methods are not easily applicable to spores due to their small size and strong autofluorescence. Here, we use the bacterial bioluminescence system and a highly sensitive microscope to measure metabolic dynamics in thousands of B. subtilis spores as they germinate. We observe and quantitate large variations in the bioluminescence dynamics across individual spores that can be decomposed into contributions from variability in germination timing, the amount of endogenously produced luminescence substrate and the intracellular reducing power. This work shows that quantitative measurement of spore metabolism is possible and thus it opens avenues for future study of the thermodynamic nature of dormant states.

Use of airborne lidar for estimating canopy gap fraction and leaf area index of tropical montane forests

2015 ◽  
Vol 36 (10) ◽  
pp. 2569-2583 ◽  
Author(s):  
Janne Heiskanen ◽  
Lauri Korhonen ◽  
Jesse Hietanen ◽  
Petri K.E. Pellikka
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Gap ◽  
Airborne Lidar ◽  
Montane Forests ◽  
Area Index ◽  
Tropical Montane Forests ◽  
Gap Fraction

scholarly journals Linking Patterns and Processes of Tree Community Assembly Across Spatial Scales in Tropical Montane Forests

2020 ◽  
Vol 101 (3) ◽  
Author(s):  
Guillermo Bañares‐de‐Dios ◽  
Manuel J. Macía ◽  
Íñigo Granzow‐de la Cerda ◽  
Itziar Arnelas ◽  
Gabriel Martins Carvalho ◽  
...  
Keyword(s):  
Community Assembly ◽  
Spatial Scales ◽  
Montane Forests ◽  
Tropical Montane Forests ◽  
Tree Community ◽  
Patterns And Processes
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