Effects of minor drainages on woody species distributions in a successional floodplain forest

1981 ◽  
Vol 11 (3) ◽  
pp. 671-676 ◽  
Author(s):  
Kenneth Buchholz
Keyword(s):  
Environmental Gradient ◽  
Woody Species ◽  
Species Distributions ◽  
River System ◽  
Floodplain Forests ◽  
Density Distributions ◽  
River Floodplains ◽  
Drainage Patterns ◽  
Sampling Position ◽  
Complex Gradient

A complex gradient of environmental factors exists on river floodplains oriented perpendicular to and affected by the river system. Previous investigations on the development and structure of floodplain forests have not adequately considered the possible effects of minor drainages intersecting the floodplains on vegetation distributions. The density distributions of Fraxinusamericana and Cornusflorida in the lower floodplain region of a portion of the Raritan River system intersected by Chambers Brook in central New Jersey illustrate that minor drainages may be dominant landscape features affecting woody species distributions. Minor drainages appear to primarily affect flooding and drainage patterns and thereby alter the orientation of the complex environmental gradient associated with the river system. When sampling on a floodplain it is important to consider sampling position relative to all drainages to ensure that samples collected at various locations along the floodplain represent similar sets of environmental conditions.

scholarly journals Urban Rivers as Dispersal Corridors: Which Factors Are Important for the Spread of Alien Woody Species along the Danube?

2020 ◽  
Vol 12 (6) ◽  
pp. 2185
Author(s):  
Sabrina Wagner ◽  
Dietmar Moser ◽  
Franz Essl
Keyword(s):  
Population Density ◽  
Robinia Pseudoacacia ◽  
Woody Species ◽  
Ailanthus Altissima ◽  
Fraxinus Pennsylvanica ◽  
Floodplain Forests ◽  
Urban Rivers ◽  
Urban Habitats ◽  
Acer Negundo ◽  
Gallery Forests

Cities are hotspots of invasions, and this is particularly the case for urban rivers, which are known to serve as corridors for the spread of alien plant species to floodplain forests. Here, we present a case study on woody (shrubs, trees) species invasions across a gradient from a metropolis (Vienna) to rural regions along the Danube River in eastern Austria. In total, we identified 44 native and 25 alien woody species in 75 plots. Five alien woody species occur in at least 10 plots. The most wide-spread ones were species of floodplain forests (Acer negundo, Fraxinus pennsylvanica, and Populus x canadensis), while Ailanthus altissima and Robinia pseudoacacia—which prefer dry sites—were recorded substantially less often. The average level of invasion—i.e., the relative proportion of alien to native woody species in plots—was high across all three study regions. Still, there was a moderate decline of alien woody species richness along the urban—peri-urban—rural gradient. Generalized Linear Mixed Models showed that population density and the proportion of urban habitats in the environs of the plots is significantly positively correlated with the presence of Acer negundo and Ailanthus altissima. Conversely, the occurrence of Robinia pseudoacacia is negatively correlated with surrounding population density and urban habitats. Occurrence of Acer negundo is positively correlated with urban habitats. For Fraxinus pennsylvanica, we found no significant relationships. Our results confirm that gallery forests at river banks are highly susceptible to invasions. We argue that managing alien woody species in urban and peri-urban sites is not appropriate and useful, given that re-invasion is likely in most cases (from adjacent urban green spaces). We acknowledge that this recommendation entails the implicit recognition that gallery forests along urban sections of the Danube will contain a substantial—and likely further increasing—proportion of alien woody species.

scholarly journals Mutation accumulation and the formation of range limits

2015 ◽  
Vol 11 (1) ◽  
pp. 20140871 ◽  
Author(s):  
Roslyn C. Henry ◽  
Kamil A. Bartoń ◽  
Justin M. J. Travis
Keyword(s):  
Growth Rate ◽  
Deleterious Effect ◽  
Environmental Gradient ◽  
Species Distributions ◽  
Mutation Accumulation ◽  
Range Limits ◽  
Deleterious Mutations ◽  
Mutation Load ◽  
Limited Growth ◽  
Marginal Populations

The dynamics of range formation are important for understanding and predicting species distributions. Here, we focus on a process that has thus far been overlooked in the context of range formation; the accumulation of mutation load. We find that mutation accumulation severely reduces the extent of a range across an environmental gradient, especially when dispersal is limited, growth rate is low and mutations are of intermediate deleterious effect. Our results illustrate the important role deleterious mutations can play in range formation. We highlight this as a necessary focus for further work, noting particularly the potentially conflicting effects dispersal may have in reducing mutation load and simultaneously increasing migration load in marginal populations.

Distribution and postglacial dispersal of freshwater fishes of Labrador

1986 ◽  
Vol 64 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Geoff A. Black ◽  
J. Brian Dempson ◽  
W. J. Bruce
Keyword(s):  
Species Distributions ◽  
River System ◽  
Great Lakes Basin ◽  
Coastal Regions ◽  
The Third ◽  
The North ◽  
Major Region ◽  
The Common ◽  
Dispersal Routes ◽  
North And South

The voluminous literature on the freshwater and diadromous fishes of Labrador is summarized in distributional maps. A total of 25 obligate freshwater spawning and one catadromous species has been reported. Fishes from Atlantic and Mississippi refugia probably invaded the region from the Great Lakes basin primarily via glacial Lake Barlow-Ojibway, crossing Quebec north of the Otish Mountain to the headwaters of the Churchill River system. Additional dispersal routes existed to the north and south. Euryhaline species from an Atlantic refugium first invaded coastal regions during postglacial depression and marine inundation. Remnants of these occur as landlocked populations. Labrador is divided into three major ichthyogeographic regions based on species distributions and dispersal opportunities. The Churchill River forms one region and is divided into three subregions. Upstream of Churchill Falls there is only one species, which dispersed across Quebec. Downstream areas, including accessible tributaries, have all of the common fishes present in Labrador. Less accessible watersheds south of Churchill River form the third subregion and are limited to fishes with better swimming abilities. The second major region is southeastern Labrador which has euryhaline fishes from Atlantic refugia and three species from Quebec. The third major region is loosely defined as northern Labrador (> 55°N) although it is one of decreasing numbers of species with increasing latitude.

Detecting the influence of climatic variables on species distributions: a test using GIS niche-based models along a steep longitudinal environmental gradient

2008 ◽  
Vol 35 (4) ◽  
pp. 637-646 ◽  
Author(s):  
Gabriel C. Costa ◽  
Christina Wolfe ◽  
Donald B. Shepard ◽  
Janalee P. Caldwell ◽  
Laurie J. Vitt
Keyword(s):  
Environmental Gradient ◽  
Species Distributions ◽  
Climatic Variables

Geomorphic evidence for ancestral drainage patterns in the Zagros Simple Folded Zone and growth of the Iranian plateau

2011 ◽  
Vol 148 (5-6) ◽  
pp. 901-910 ◽  
Author(s):  
RICHARD T. WALKER ◽  
LUCY A. RAMSEY ◽  
JAMES JACKSON
Keyword(s):  
Digital Elevation Models ◽  
River System ◽  
Direct Result ◽  
Fars Province ◽  
Continuous Line ◽  
Profound Change ◽  
Iranian Plateau ◽  
Drainage Patterns ◽  
Fold And Thrust Belt ◽  
Digital Elevation

AbstractWe describe the geomorphology of a large (~10000 km2) internally draining region within the Zagros fold-and-thrust belt of Fars province, Iran. A series of wind gaps through fold crests and a continuous line of low-slope pixels in digital elevation models indicate the presence of an older, and now abandoned, through-going river system. We suggest, from the presence of the wind gaps, that the original through-going river system was abandoned as a direct result of fold growth. At present, through-going drainage in Fars is restricted to only two major rivers, the Kul and the Mand, which bound the margins of the internally drained region. The low gradients of the Kul and the Mand rivers are similar to those in topographic profiles drawn along the course of the abandoned drainage. The Mand and Kul rivers may be defeated in the future, causing an expansion of the internally drained region, and resulting in a profound change in the distribution of sediment and surface elevations within the Zagros. The internally draining part of the Zagros resembles the Central Iranian Plateau both in its geomorphology and in the apparently slow rates of deformation within it. We speculate that the development of internally drained basins and distribution of shortening within the range may be causally linked. The geomorphology that we describe might, therefore, record a stage in the southward expansion of the non-deforming and topographically high Central Iranian Plateau.

scholarly journals Predicting biotic interactions and their variability in a changing environment

2016 ◽  
Vol 12 (5) ◽  
pp. 20151073 ◽  
Author(s):  
Kohmei Kadowaki ◽  
Claire G. Barbera ◽  
William Godsoe ◽  
Frédéric Delsuc ◽  
Nicolas Mouquet
Keyword(s):  
Environmental Change ◽  
Species Distribution ◽  
Environmental Gradient ◽  
Global Environmental Change ◽  
Biotic Interactions ◽  
Species Distributions ◽  
Phylogenetic Distance ◽  
Biotic Interaction ◽  
Interacting Species ◽  
Global Environmental

Global environmental change is altering the patterns of biodiversity worldwide. Observation and theory suggest that species' distributions and abundances depend on a suite of processes, notably abiotic filtering and biotic interactions, both of which are constrained by species' phylogenetic history. Models predicting species distribution have historically mostly considered abiotic filtering and are only starting to integrate biotic interaction. However, using information on present interactions to forecast the future of biodiversity supposes that biotic interactions will not change when species are confronted with new environments. Using bacterial microcosms, we illustrate how biotic interactions can vary along an environmental gradient and how this variability can depend on the phylogenetic distance between interacting species.

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