scholarly journals Additive effects of connectivity provided by different habitat types drive plant assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Léa Uroy ◽  
Cendrine Mony ◽  
Aude Ernoult
Keyword(s):  
Empirical Studies ◽  
Agricultural Landscapes ◽  
Plant Responses ◽  
Herbaceous Plant ◽  
Habitat Types ◽  
Plant Assemblage ◽  
Dispersal Vectors ◽  
Random Expectation ◽  
Plant Assemblages ◽  
Primary Dispersal

Abstract How connectivity affects plant assemblages is a central issue in landscape ecology. So far, empirical studies have produced contradictory results, possibly because studies: (1) inaccurately assess connectivity by prioritizing the respective effect of the type of habitat on plant assemblages and (2) omit the range of possible plant responses to connectivity depending on dispersal vectors. We focused on three dominant habitat types in agricultural landscapes (woodland, grassland and cropland), and analysed the effect of connectivity on herbaceous plant assemblage similarity for three primary dispersal modes (animal-dispersed, wind-dispersed and unassisted). Using circuit theory, we measured connectivity provided by woodland, grassland and cropland habitats independently. The similarity of plant assemblages was evaluated relative to the random expectation based on the regional pool. Overall, plant assemblage similarity in woodlands and temporary grasslands was dependent on connectivity, but not in wheat croplands. Only animal-dispersed species responded to connectivity. The similarity of animal-dispersed assemblages in woodlands was increased by the connectivity provided by woodland habitats, but was reduced by cropland habitats, whereas in temporary grasslands, similarity was increased by the connectivity provided by cropland habitats. Our results suggest that animal-dispersed species supplement their dispersal pathways, thus improving our knowledge of plant assembly rules in fragmented landscapes.

scholarly journals Functional Diversity Effects of Vegetation on Runoff to Design Herbaceous Hedges for Sediment Retention

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 131
Author(s):  
Léa Kervroëdan ◽  
Romain Armand ◽  
Mathieu Saunier ◽  
Michel-Pierre Faucon
Keyword(s):  
Soil Erosion ◽  
Plant Species ◽  
Functional Diversity ◽  
Species Interactions ◽  
Agricultural Landscapes ◽  
Stem Density ◽  
Herbaceous Plant ◽  
Sediment Retention ◽  
Erosion Processes ◽  
Diversity Effects

Background: Functional diversity effects on ecosystem processes, like on soil erosion, are not fully understood. Runoff and soil erosion in agricultural landscapes are reduced by the hydraulic roughness (HR) of vegetation patches, which furthers sediment retention. Vegetation with important stem density, diameters, leaf areas, and density impact the HR. A functional structure composed of these negatively correlated traits involved in the increase of the HR would constitute a positive effect of the functional diversity. Methods: Runoff simulations were undertaken on four mono-specific and two multi-specific communities, using herbaceous plant species from North-West Europe, presenting six contrasting aboveground functional traits involved in the HR increase. Results: An effect of dominant traits in the community was found on the HR, identified as the community-weighted leaf density. The non-additive effect of functional diversity on the HR could be explained by the presence of species presenting large stems in the communities with high functional diversity. Conclusion: We argued that functional diversity effect on the HR could change due to idiosyncratic effects of the plant traits, which would be influenced by soil properties, phylogeny diversity, and plant species interactions. These findings constitute an advancement in the understanding of plant trait assemblage on runoff and soil erosion processes.

scholarly journals The total dispersal kernel: a review and future directions

AoB Plants ◽  
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Haldre S Rogers ◽  
Noelle G Beckman ◽  
Florian Hartig ◽  
Jeremy S Johnson ◽  
Gesine Pufal ◽  
...  
Keyword(s):  
Higher Order ◽  
Dispersal Kernel ◽  
Plant Responses ◽  
Conceptual Modelling ◽  
Long Distance ◽  
Population Spread ◽  
Dispersal Vectors ◽  
Additional Data Collection ◽  
Modelling Cycle

Abstract The distribution and abundance of plants across the world depends in part on their ability to move, which is commonly characterized by a dispersal kernel. For seeds, the total dispersal kernel (TDK) describes the combined influence of all primary, secondary and higher-order dispersal vectors on the overall dispersal kernel for a plant individual, population, species or community. Understanding the role of each vector within the TDK, and their combined influence on the TDK, is critically important for being able to predict plant responses to a changing biotic or abiotic environment. In addition, fully characterizing the TDK by including all vectors may affect predictions of population spread. Here, we review existing research on the TDK and discuss advances in empirical, conceptual modelling and statistical approaches that will facilitate broader application. The concept is simple, but few examples of well-characterized TDKs exist. We find that significant empirical challenges exist, as many studies do not account for all dispersal vectors (e.g. gravity, higher-order dispersal vectors), inadequately measure or estimate long-distance dispersal resulting from multiple vectors and/or neglect spatial heterogeneity and context dependence. Existing mathematical and conceptual modelling approaches and statistical methods allow fitting individual dispersal kernels and combining them to form a TDK; these will perform best if robust prior information is available. We recommend a modelling cycle to parameterize TDKs, where empirical data inform models, which in turn inform additional data collection. Finally, we recommend that the TDK concept be extended to account for not only where seeds land, but also how that location affects the likelihood of establishing and producing a reproductive adult, i.e. the total effective dispersal kernel.

Diversity of plant assemblages dampens the variability of the growing season phenology of wetland ecosystems

2020 ◽  
Author(s):  
Guillaume Rheault ◽  
Esther Lévesque ◽  
Raphaël Proulx
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Anthropogenic Activities ◽  
Growing Season ◽  
Edaphic Factors ◽  
Global Functioning ◽  
Wetland Ecosystems ◽  
Growing Season Length ◽  
Plant Assemblage ◽  
Plant Assemblages

Abstract Background: The functioning of ecosystems is highly variable through space and time. Climatic and edaphic factors are forcing ecological communities to converge, whereas the diversity of plant assemblages dampens these effects by allowing communities’ dynamics to diverge. This study evaluated whether the growing season phenology of plant communities within wetland ecosystems is determined by the climatic/edaphic factors of contrasted regions, by the species richness of plant communities, or by the diversity of plant assemblages. From 2013 to 2016, we monitored the phenology and floristic composition of 118 plant communities across five wetland ecosystems distributed along a gradient of edaphic and climatic conditions in the Province of Quebec, Canada. Results: Growing season phenology of wetlands was driven by differences among plant assemblage within ecosystems, and not by the species richness of each individual community (<1% of the explained variation). Variation in the growing season length of wetlands reflected a balance between the effects of climatic and edaphic factors on green-up dates and the dampening effects of plant assemblage diversity on green-down dates. Conclusions: The latter dampening effect may be particularly important in the context of increasing anthropogenic activities, which are predicted to impair the ability of wetlands to adapt to fluctuating environmental conditions. Our findings suggest that stakeholders should not necessarily consider local monospecific plant communities of lower conservation value to the global functioning of wetland ecosystems.

scholarly journals Relationships between bees (Hymenoptera: Apoidea: Apiformes) and flowers in the Bulgarian agricultural landscape

2015 ◽  
Vol 84 (2) ◽  
pp. 101-126 ◽  
Author(s):  
Józef Banaszak ◽  
Piotr Szefer ◽  
Bojana Dochkova
Keyword(s):  
Apis Mellifera ◽  
Species Composition ◽  
Agricultural Landscape ◽  
Niche Overlap ◽  
Agricultural Landscapes ◽  
Food Plants ◽  
Individual Plant ◽  
Habitat Types ◽  
Factors Influencing ◽  
Pollinating Insects

Abstract The species composition and number of visitations of food plants by bees were studied in refuge sites in agricultural landscapes and in selected crops. The habitat fragments of interest are characterised in terms of pollinator diversity at genus level and the use of food plants by individual genera. Trophic and temporal niche overlap is described for individual genera and the honey bee Apis mellifera in different habitat types. Factors influencing the manner of use of individual plant species by pollinating insects are identified

scholarly journals Trait Estimation in Herbaceous Plant Assemblages from in situ Canopy Spectra

2013 ◽  
Vol 5 (12) ◽  
pp. 6323-6345 ◽  
Author(s):  
Hans Roelofsen ◽  
Peter van Bodegom ◽  
Lammert Kooistra ◽  
Jan-Philip Witte
Keyword(s):  
Herbaceous Plant ◽  
Plant Assemblages ◽  
Trait Estimation

scholarly journals Diversity of plant assemblages dampens the variability of the growing season phenology in wetland landscapes

2020 ◽  
Author(s):  
Guillaume Rheault ◽  
Esther Lévesque ◽  
Raphaël Proulx
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Growing Season ◽  
Edaphic Factors ◽  
Wetland Plant ◽  
Global Functioning ◽  
Growing Season Length ◽  
Wetland Plant Communities ◽  
Plant Assemblage ◽  
Plant Assemblages

Abstract Background: The functioning of ecosystems is highly variable through space and time. Climatic and edaphic factors are forcing ecological communities to converge, whereas the diversity of plant assemblages dampens these effects by allowing communities’ dynamics to diverge. This study evaluated whether the growing season phenology of wetland plant communities within landscapes is determined by the climatic/edaphic factors of contrasted regions, by the species richness of plant communities, or by the diversity of plant assemblages. From 2013 to 2016, we monitored the phenology and floristic composition of 118 wetland plant communities across five landscapes distributed along a gradient of edaphic and climatic conditions in the Province of Québec, Canada. Results: The growing season phenology of wetlands was driven by differences among plant assemblage within landscapes, and not by the species richness of each individual community (<1% of the explained variation). Variation in the growing season length of wetlands reflected the destabilizing effect of climatic and edaphic factors on green-up dates, which is opposed to the dampening effect of plant assemblage diversity on green-down dates. Conclusions: The latter dampening effect may be particularly important in the context of increasing anthropogenic activities, which are predicted to impair the ability of wetlands to adapt to fluctuating environmental conditions. Our findings suggest that stakeholders should not necessarily consider local monospecific plant communities of lower conservation value to the global functioning of wetland ecosystems.

scholarly journals Seed ingestion and germination in rattlesnakes: overlooked agents of rescue and secondary dispersal

2018 ◽  
Vol 285 (1872) ◽  
pp. 20172755 ◽  
Author(s):  
Randall S. Reiserer ◽  
Gordon W. Schuett ◽  
Harry W. Greene
Keyword(s):  
Seed Dispersal ◽  
Population Ecology ◽  
Empirical Studies ◽  
Evolutionary Process ◽  
Terrestrial Plants ◽  
Frugivorous Birds ◽  
Secondary Dispersal ◽  
Cheek Pouches ◽  
Primary Dispersal

Seed dispersal is a key evolutionary process and a central theme in the population ecology of terrestrial plants. The primary producers of most land-based ecosystems are propagated by and maintained through various mechanisms of seed dispersal that involve both abiotic and biotic modes of transportation. By far the most common biotic seed transport mechanism is zoochory, whereby seeds, or fruits containing them, are dispersed through the activities of animals. Rodents are one group of mammals that commonly prey on seeds (granivores) and play a critical, often destructive, role in primary dispersal and the dynamics of plant communities. In North America, geomyid, heteromyid and some sciurid rodents have specialized cheek pouches for transporting seeds from plant source to larder, where they are often eliminated from the pool of plant propagules by consumption. These seed-laden rodents are commonly consumed by snakes as they forage, but unlike raptors, coyotes, bobcats, and other endothermic predators which eat rodents and are known or implicated to be secondary seed dispersers, the role of snakes in seed dispersal remains unexplored. Here, using museum-preserved specimens, we show that in nature three desert-dwelling rattlesnake species consumed heteromyids with seeds in their cheek pouches. By examining the entire gut we discovered, furthermore, that secondarily ingested seeds can germinate in rattlesnake colons. In terms of secondary dispersal, rattlesnakes are best described as diplochorous. Because seed rescue and secondary dispersal in snakes has yet to be investigated, and because numerous other snake species consume granivorous and frugivorous birds and mammals, our observations offer direction for further empirical studies of this unusual but potentially important channel for seed dispersal.

Soil and herbaceous plant responses to summer patch burns under continuous and rotational grazing

2010 ◽  
Vol 137 (1-2) ◽  
pp. 113-123 ◽  
Author(s):  
W.R. Teague ◽  
S.L. Dowhower ◽  
S.A. Baker ◽  
R.J. Ansley ◽  
U.P. Kreuter ◽  
...  
Keyword(s):  
Plant Responses ◽  
Herbaceous Plant ◽  
Rotational Grazing

scholarly journals Do successive climate extremes weaken the resistance of plant communities? An experimental study using plant assemblages

2014 ◽  
Vol 11 (1) ◽  
pp. 109-121 ◽  
Author(s):  
F. E. Dreesen ◽  
H. J. De Boeck ◽  
I. A. Janssens ◽  
I. Nijs
Keyword(s):  
Plant Communities ◽  
Extreme Event ◽  
Recovery Period ◽  
Climate Extremes ◽  
Herbaceous Plant ◽  
Short Term ◽  
Positive Effects ◽  
Negative Effect ◽  
Plant Assemblages ◽  
Heat Extremes

Abstract. The probability that plant communities undergo successive climate extremes increases under climate change. Exposure to an extreme event might elicit acclimatory responses and thereby greater resistance to a subsequent event, but might also reduce resistance if the recovery period is too short or resilience too low. Using experimental herbaceous plant assemblages, we compared the effects of two successive extremes occurring in one growing season (either two drought extremes, two heat extremes or two drought + heat extremes) to those of assemblages being exposed only to the second extreme. Additionally, the recovery period between the successive extremes was varied (2, 3.5 or 6 weeks). Among the different types of climate extremes, combined heat + drought extremes induced substantial leaf mortality and plant senescence, while the effects of drought and heat extremes were smaller. Preceding drought + heat extremes lowered the resistance in terms of leaf survival to a subsequent drought + heat extreme if the recovery period was two weeks, even though the leaves had completely recovered during that interval. No reduced resistance to subsequent extremes was recorded with longer recovery times or with drought or heat extremes. Despite the substantial mortality on the short term, the drought + heat and the heat extremes increased the end-of-season aboveground biomass independent of the number of extreme events or the duration of the recovery period. These results show that recurrent climate extremes with short time intervals can weaken the resistance of herbaceous plant assemblages. This negative effect in the short term can, however, be compensated in the longer term through rapid recovery and secondary positive effects.

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