Fragmentation and edge effects on plant-animal interactions, ecological processes and biodiversity.

2009 ◽  
pp. 69-101 ◽  
Author(s):  
F. López-Barrera ◽  
J. J. Armesto ◽  
G. Williams-Linera ◽  
C. Smith-Ramírez ◽  
R. H. Manson
Keyword(s):  
Edge Effects ◽  
Ecological Processes ◽  
Plant Animal Interactions

scholarly journals Seed dispersal syndromes in the Madagascan flora: the unusual importance of primates

Oryx ◽  
2018 ◽  
Vol 52 (3) ◽  
pp. 418-426 ◽  
Author(s):  
Aurélie Albert-Daviaud ◽  
Sarah Perillo ◽  
Wolfgang Stuppy
Keyword(s):  
Seed Dispersal ◽  
Data Science ◽  
Plant Traits ◽  
Bird Species ◽  
Lower Percentage ◽  
Endemic Plant ◽  
Ecological Processes ◽  
Dispersal Syndromes ◽  
Plant Animal Interactions ◽  
Lemur Species

AbstractMadagascar is one of the most threatened biodiversity hotspots, and protection of its biodiversity is becoming increasingly urgent as deforestation of the island continues. For the long-term success of conservation efforts it is essential that key ecological processes, such as seed dispersal, are protected and restored. Therefore, the identification of ecological gaps is a vital task. For Madagascar, only little is known about plant–animal interactions, and traditional methods of ecological research are too time-consuming to provide crucial information about breakdowns in these interactions. To identify likely dispersal gaps we therefore used a theoretical approach to analyse plant–disperser interactions in Madagascar. We used data science tools to impute missing data on relevant plant traits to subsequently predict the most likely dispersal agents for each of Madagascar's endemic plant species. We found that 38% of the endemic species (N = 8,784) are endozoochorous, and among these 26–41% display a primate syndrome and 17–19% a bird syndrome (depending on the definition of syndromes). This lower percentage of endozoochorous species and higher percentage of species with a primate syndrome in Madagascar compared to other tropical areas reflects the unusual disperser guild on the island. Only five bird species but 20 lemur species are frugivorous, and 16 of those lemur species are currently threatened with extinction. The disappearance of frugivorous lemurs would significantly change the vegetation dynamics of Madagascar's ecosystems, and a high proportion of Madagascar's endemic plants would enter an extinction vortex.

Edge Effects Are Not Linked to Key Ecological Processes in a Fragmented Biogenic Reef

2020 ◽  
Vol 43 (4) ◽  
pp. 708-721 ◽  
Author(s):  
Camilla Bertolini ◽  
W. I. Montgomery ◽  
Nessa E. O’Connor
Keyword(s):  
Edge Effects ◽  
Ecological Processes

Ecology of meadow steppe in northeast China

2008 ◽  
Vol 30 (2) ◽  
pp. 247 ◽  
Author(s):  
D. Wang ◽  
L. Ba
Keyword(s):  
Climate Change ◽  
Past Research ◽  
Grassland Management ◽  
Future Research ◽  
Meadow Steppe ◽  
Ecological Processes ◽  
Plant Adaptation ◽  
North East ◽  
Vegetation Production ◽  
Plant Animal Interactions

Native grassland in China is mostly meadow, typical or desert steppe and comprises 400 million hectares, ~40% of the land area. We review past research on the meadow steppe of north-east China. Our foci are plant adaptation to climate, edaphic-related and defoliation stresses, vegetation production, grassland management, herbivore foraging behaviour, safe stocking rates, plant-animal interactions, ecosystem functioning, conservation of biodiversity and the influence of climate change on grassland function. Recent studies have provided some insights into ecological processes and functioning of meadow steppe, and have enabled better identification of research opportunities. Key areas identified for future research include plant adaptation, grassland function and value, monitoring of range health, ecological consequences of climate change on biodiversity and ecosystem function.

scholarly journals Temporal edge effects structure the assemblages of Drosophilidae (Diptera) in a Restinga forest fragment in Southern Brazil

2021 ◽  
Vol 16 (2) ◽  
pp. 299-315
Author(s):  
Mayara Ferreira Mendes ◽  
Monica Laner Blauth ◽  
Luana Amaral Dos Santos ◽  
Vera Lúcia da Silva Valente Gaiesky ◽  
Marco Silva Gottschalk
Keyword(s):  
Decision Making ◽  
Edge Effects ◽  
Seasonal Patterns ◽  
Southern Brazil ◽  
Forest Fragment ◽  
Ecological Processes ◽  
Fragmented Landscapes ◽  
Anthropogenic Habitat ◽  
South Of Brazil ◽  
Asymmetrically Distributed

Anthropogenic habitat fragmentation directly affects ecological processes, leading to negative biodiversity impacts for insects and other biota. Increased edge effects are one consequence of fragmentation, and may alter the composition or abundance of species in the remaining habitat fragments. Understanding the ways in which edge effects impact upon the biota is essential for conservation decision-making in fragmented landscapes. Therefore, the aim of this study was to analyze the seasonal patterns of abundance, richness, and composition of Drosophilidae in a Restinga forest fragment in the extreme south of Brazil, as a function of the distance from the edge to the interior of the fragment. The data were analyzed using SIMPER analyses, which showed that the edge and the forest interior were most dissimilar during winter, followed by spring, autumn and summer. An NMDS and the SIMPER analyses showed that the lower dissimilarity between the edge and interior in spring, autumn and summer, compared to winter, is driven by immigration of individuals from outside of the forest fragment. Furthermore, some species were asymmetrically distributed in the fragment, with some species restricted to the edge of the fragment and others to the interior. This information aids in the understanding of the functioning and dynamics of fragmentation, which is fundamental for the maintenance and integrity of environments and their fauna.

scholarly journals Shifts between cooperation and antagonism driven by individual variation: A systematic synthesis review

2020 ◽  
Author(s):  
Nicholas Patrick Moran ◽  
Barbara Caspers ◽  
Nayden Chakarov ◽  
Uli Ernst ◽  
Claudia Fricke ◽  
...  
Keyword(s):  
Phenotypic Variation ◽  
Future Research ◽  
Synthesis Methods ◽  
Ecological Interactions ◽  
Trait Variation ◽  
Ecological Processes ◽  
Intraspecific Trait Variation ◽  
Plant Animal Interactions ◽  
Aggressive Personality

The outcomes of ecological interactions fall along a continuum from cooperative (mutually beneficial) to antagonistic (detrimental to one or both parties). This applies at both interspecific (e.g. plant-animal interactions) and intraspecific levels (e.g. male-female interactions). Phenotypic variation among individuals is increasingly being recognised as an important factor in ecological processes, and trait variation in either interacting party may determine the outcome of the interaction, such as whether a symbiont provides net costs or benefits to their host, or whether two conspecifics decide to cooperatively forage or to compete over food. This systematic review investigates the role of intraspecific trait variation (‘ITV’) in determining the cooperative-antagonistic outcome of ecological interactions. Based on a literature collection of 95 empirical and theoretical publications meeting our inclusion criteria, we give an overview of the various mechanisms that can lead to shifts between antagonism and cooperation within or between species. We describe two broad classes of interrelated mechanisms that may drive shifts in outcomes. First, trait frequency effects occur when processes influencing a population’s composition of traits linked to cooperation or antagonism (e.g. aggressive personality types, cheater/exploiter phenotypes etc.) lead to net shifts in interaction outcome. Second, systemic variance effects occur when changes in the amount of ITV in the population (as opposed to the mean phenotype) is the factor driving shifts. Both heritable genetic differences among individuals and phenotypic plasticity are important sources of phenotypic variation. The specific mix of heritable vs. plastic ITV may determine whether a change from cooperative to antagonistic, or vice versa, is likely to be short-term (i.e. context-dependent) or lead to more persistent shifts (e.g. mutualism breakdown). To guide future research on this topic we describe knowledge gaps and divergences between empirical and theoretical literature, further highlighting the value of applying research synthesis methods in ecology and evolution.

The role of habitat area and edge in fragmented landscapes: definitively distinct or inevitably intertwined?This review is one of a series dealing with some aspects of the impact of habitat fragmentation on animals and plants. This series is one of several virtual symposia focussing on ecological topics that will be published in the Journal from time to time.

2007 ◽  
Vol 85 (10) ◽  
pp. 1017-1030 ◽  
Author(s):  
Robert J. Fletcher, Jr. ◽  
Leslie Ries ◽  
James Battin ◽  
Anna D. Chalfoun
Keyword(s):  
Edge Effects ◽  
Patch Size ◽  
Field Studies ◽  
Potential Effect ◽  
Relative Effect ◽  
Ecological Processes ◽  
Fragmented Landscapes ◽  
Habitat Area ◽  
Independent Effects ◽  
The Impact

Over the past few decades, much research has focussed on the effects of habitat area (i.e., patch size) and edges in fragmented landscapes. We review and synthesize the literature on area and edge effects to identify whether the ecological processes influenced by patch size and edge are distinct, to summarize evidence for the relative effect of each, and to discuss how estimating their independent effects may be accomplished in field studies. Area and edge directly influence ecological processes in distinct ways, yet indirect effects can be similar, making it difficult to isolate the effects of area and edge in nature. Many studies investigating both area and edge have been confounded in their design and (or) analysis (i.e., studies did not control for one potential effect while testing for the other). Nonconfounded studies have more frequently shown support for edge effects, and comparisons between nonconfounded and confounded studies suggest that some observed area effects could be explained by edge effects. We argue that by focussing on the fundamental processes directly influenced by area and edge, and by developing more rigorous study designs and analyses that isolate their relative influence, greater insight can be gained in future investigations on habitat loss and fragmentation.

scholarly journals Forest Fragmentation Slows the Decomposition of Coarse Woody Debris in a Subtropical Forest

2021 ◽  
Author(s):  
Chunsheng Wu ◽  
Chunjie Shu ◽  
Zhijian Zhang ◽  
Yanyan Li ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Mass Loss ◽  
Forest Fragmentation ◽  
Edge Effects ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Forest Edge ◽  
Ecosystem Functions ◽  
Ecological Processes ◽  
Fragmented Forests

Abstract Forest fragmentation is increasing rapidly around the world, and edge effects caused by fragmented forests can influence ecosystem functions and ecological processes, including coarse woody debris (CWD) decomposition. Understanding the influencing mechanisms of edge effect on CWD decomposition is needed to assess the effects of forest fragmentation on carbon cycling and storage. We measured rates of mass loss of CWD of Cinnamomum camphora (L.) Presl. and Pinus taiwanensis Hayata over two years at two distances (0−5 m versus 60 m) from a forest edge at two altitudes (215 and 1,400 m a.s.l.), in a subtropical forest. In addition, we determined the microbial community of each CWD segment and the soil beneath via phospholipid fatty acids (PLFAs). Mass loss of CWD 60 m from the forest edge was 15% greater than that at the edge (0–5 m). Mass loss was positively correlated with the abundance of microbial and fauna community and moisture content of the decaying CWD. Distance from edge explained 17.4% of the total variation of the microbial abundance in CWD. The results indicate that the reduced abundance of microbial and fauna communities and moisture content at forest edges influenced rates of decomposition of CWD. Long-term experiments with more tree species and more forest types are needed to better assess edge effects generally. Study Implications Forest fragmentation is increasing rapidly around the world, and edge effects caused by fragmented forests can influence ecosystem functions and ecological processes, including coarse woody debris (CWD) decomposition. Understanding the influencing mechanisms of edge effect on CWD decomposition is needed to assess the effects of forest fragmentation on carbon cycling and storage. The results of this study indicate that the reduced abundance of microbial and fauna communities and moisture content at forest edges reduced rates of decomposition of CWD. Long-term experiments with more tree species and more forest types are needed to assess the edge effect’s generality.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

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