Interactions between nurse-plants and an exotic invader along a tropical alpine elevation gradient: growth-form matters

Alpine Botany ◽  
2020 ◽  
Vol 130 (1) ◽  
pp. 59-73
Author(s):  
Luis D. Llambí ◽  
Aure Durbecq ◽  
Karla Cáceres-Mago ◽  
Alicia Cáceres ◽  
Lirey Ramírez ◽  
...  
Keyword(s):  
Growth Form ◽  
Elevation Gradient ◽  
Nurse Plants ◽  
Tropical Alpine

scholarly journals Microclimatic Warming Leads to a Decrease in Species and Growth Form Diversity: Insights From a Tropical Alpine Grassland

2021 ◽  
Vol 9 ◽  
Author(s):  
Sisimac A. Duchicela ◽  
Francisco Cuesta ◽  
Carolina Tovar ◽  
Priscilla Muriel ◽  
Ricardo Jaramillo ◽  
...  
Keyword(s):  
Plant Community ◽  
Growth Form ◽  
Dry Season ◽  
Rate Of Change ◽  
Community Diversity ◽  
Alpine Regions ◽  
Air Temperatures ◽  
Thermal Amplitude ◽  
Soil Temperatures ◽  
Tropical Alpine

Due to warming, changes in microclimatic temperatures have shifted plant community structure and dynamics in tundra and alpine regions. The directionality and magnitude of these changes are less known for tropical alpine ecosystems. To understand the likely trajectory of these shifts in the Andes, we conducted a warming experiment in the northern Andes—using open-top chambers (OTC). In this study, we ask (1) how do OTCs affect air and soil temperatures in microclimates of tropical alpine regions, year-round and during the dry season? (2) What are the effects of 7 years of warming on (a) the aboveground biomass (AGB) and (b) the plant taxonomic and growth form diversity? We installed five monitoring blocks in 2012 at ca. 4,200 m asl with 20 OTCs and 50 control plots randomly distributed within each block. We measured AGB, plant community diversity, and growth form diversity between 2014 and 2019. After 7 years of warming, we found significant increases in mean monthly (+0.24°C), daily (+0.16°C), and night air temperatures (+0.33°C) inside the OTCs, and the OTCs intensified microclimatic conditions during the dry season. Additionally, OTCs attenuated extreme temperatures—particularly in the soil—and the number of freezing events. AGB significantly increased in OTCs, and by 2019, it was 27% higher in OTCs than in control. These changes were driven mainly by a progressive increment of tussock grasses such as Calamagrostis intermedia, typical of lower elevations. The increase of tussocks led to a significant decrease in species diversity and evenness inside OTCs, but not in species richness after accounting by sampling time. Furthermore, cushions and herbs decreased inside OTCs. Our results show that experimental warming using OTCs in equatorial regions leads to decreased daily thermal amplitude and night temperatures rather than the level of increase in mean temperatures observed in temperate regions. The increase of tussocks and decrease in diversity of species and growth forms due to prolonged modifications in microclimatic temperature might be a step toward shrub-dominated ecosystems. Further research on this topic would help understand shifts in growth form dominance and the direction and rate of change of the system.

scholarly journals Temperature Microclimates of Plants in a Tropical Alpine Environment: How Much does Growth Form Matter?

2016 ◽  
Vol 48 (1) ◽  
pp. 61-78 ◽  
Author(s):  
Petr Sklenář ◽  
Andrea Kučerová ◽  
Jana Macková ◽  
Katya Romoleroux
Keyword(s):  
Growth Form ◽  
Alpine Environment ◽  
Tropical Alpine

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

Herbicide Tolerance Of Transgenic `Stevens' Cranberry Plants Depends on the Test Environment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 517a-517
Author(s):  
Eric L. Zeldin ◽  
Rodney A. Serres ◽  
Brent H. McCown
Keyword(s):  
Growth Form ◽  
Herbicide Tolerance ◽  
Genetically Engineered ◽  
Shoot Tip ◽  
Test Environment ◽  
Growth Environment ◽  
Commercial Formulation ◽  
Tolerance Level ◽  
Delayed Growth ◽  
Significant Injury

`Stevens' cranberry was genetically engineered to confer tolerance to the broad spectrum herbicide glufosinate. Initially, herbicide tolerance was verified by spraying greenhouse plants with the commercial formulation Liberty. Although one transformant showed significant tolerance, the tolerance level was below that required to kill goldenrod, a common weed of cranberry beds. This transformant was propagated and the plants established outdoors in a coldframe, yielding a growth form more typical of field-grown plants than that of greenhouse-grown plants. These plants, as well as untransformed cranberry and goldenrod plants, were sprayed with various levels of the herbicide. The transformed plants were not killed at glufosinate concentrations up to 1000 ppm, although delayed growth did occur. Some runner tip injury was observed at 500 ppm as well as widespread shoot tip death at higher levels. The above-ground parts of goldenrod plants were killed at 400 ppm with significant injury at 200 ppm. Untransformed cranberry plants were killed at 300 ppm and had extensive tip death even at 100 ppm. Transformed cranberry plants with confirmed “field” tolerance were re-established in the greenhouse and new vegetative growth was forced. When these plants were sprayed with glufosinate, significant shoot tip injury was observed at levels as low as 100 ppm. The degree of herbicide tolerance of transformed cranberry appears to be modulated by the growth environment, which may affect the expression of the inserted genes or the physiological sensitivity of the impacted tissues.

Form and Function of Mediterranean Shrublands

2018 ◽  
Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt
Keyword(s):  
Convergent Evolution ◽  
Growth Form ◽  
Structure And Function ◽  
Adaptive Traits ◽  
Shrub Species ◽  
Leaf Type ◽  
Evergreen Shrub ◽  
Form And Function ◽  
Considerable Research ◽  
And Function

The archetypal shrub type that dominates most of the regions that experience mediterranean-type climate (MTC) is an evergreen shrub with thick and leathery leaves (sclerophyllous). The occurrence of large stands of such shrubs in all MTC regions led early biogeographers to hypothesize that the MTC selects for this growth form and leaf type and that this had led to convergent evolution (see Chapters 1 and 2). This hypothesis has received considerable research interest and continues to be examined. In this chapter we consider the structure and physiology of these archetypal MTC region shrub species and examine evidence for convergent evolution in their structure and function. We also assess the key adaptive traits that enable the shrub species that compose mediterranean-type vegetation (MTV) communities to thrive in MTC regions.

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