scholarly journals Testing small‐scale ecological gradients and intraspecific differentiation for hundreds of kelp forest species using haplotypes from metabarcoding

2021 ◽  
Author(s):  
Peter Shum ◽  
Stephen R. Palumbi
Keyword(s):  
Kelp Forest ◽  
Small Scale ◽  
Forest Species ◽  
Ecological Gradients ◽  
Intraspecific Differentiation

scholarly journals Disturbance intensity, disturbance extent and ocean climate modulate kelp forest understory communities

2020 ◽  
Vol 651 ◽  
pp. 57-69
Author(s):  
T Wernberg ◽  
M Couraudon-Réale ◽  
F Tuya ◽  
M Thomsen
Keyword(s):  
Functional Groups ◽  
Kelp Forest ◽  
Forest Understory ◽  
Small Scale ◽  
Kelp Forests ◽  
Ocean Climate ◽  
Disturbance Regimes ◽  
Disturbance Intensity ◽  
Control Community ◽  
Understory Communities

Disturbances often control community structure by removing large dominant species, allowing new species to colonize. Disturbances vary in intensity and extent, and their effects on resident communities can depend on local environmental conditions. We tested the effects of disturbance intensity and extent on different functional groups of understory species in kelp forests at 4 locations along an ocean climate gradient in Western Australia. We hypothesized that, compared to intact canopies, increasing disturbance intensities (50 and 100% of kelp removal) and extents (2, 4 and 8 m diameter) would promote light-dependent competitors (turf, foliose, articulated coralline and fucoid seaweeds) at the expense of less light-dependent functional groups (invertebrates and encrusting seaweeds). We also hypothesized that these effects would be most pronounced at warmer relative to cooler locations, where metabolic and ecological rates are faster. The first hypothesis was supported; light-dependent understory groups (turfs, in particular) increased, while less light-dependent groups (crusts in particular) decreased with increasing disturbance regimes. However, the second hypothesis was not supported; even though understory communities differed between locations and turf covers were highest at the warmest location, we found no significant interactions between locations and disturbance regimes. Importantly, our results revealed that even small-scale partial canopy loss can have significant effects on kelp-associated communities. The implied community-wide, density-dependent effects have implications for the management and conservation of kelp forests, because restoration of ecological functions must also consider the density of kelp forests, not simply their presence or absence.

Small-scale patterning in the recruitment of forest species during succession in tropical dry forest, Mozambique

Vegetatio ◽  
1990 ◽  
Vol 87 (1) ◽  
pp. 51-57 ◽  
Author(s):  
B. M. Campbell ◽  
T. Lynam ◽  
J. C. Hatton
Keyword(s):  
Tropical Dry Forest ◽  
Dry Forest ◽  
Small Scale ◽  
Forest Species

The value of a broad temporal and spatial perspective in understanding dynamics of kelp forest ecosystems

2016 ◽  
Vol 67 (1) ◽  
pp. 14 ◽  
Author(s):  
Daniel C. Reed ◽  
Andrew R. Rassweiler ◽  
Robert J. Miller ◽  
Henry M. Page ◽  
Sally J. Holbrook
Keyword(s):  
Forest Ecosystems ◽  
Spatial Scales ◽  
Kelp Forest ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Short Term ◽  
Spatial Perspective ◽  
Ecological Responses ◽  
Temporal And Spatial

Many ecological processes play out over longer time scales and larger spatial scales than can be studied in a traditional 2–4-year grant cycle. Uncertainties in future funding hinder efforts to implement comprehensive research programs that integrate coupled time series observations of physical variables and ecological responses, manipulative experiments and synthetic analyses over the long term. Such research is essential for advancing our understanding of ecological responses associated with climate change, and the physical and biological processes that control them. This need is perhaps greatest for ecosystems that display highly dynamic and spatially complex patterns that are difficult to explain with short-term, small-scale studies. Such is the case for kelp forest ecosystems, which often show tremendous spatial and temporal variability in resource supply, consumer control and physical disturbance across spatial scales of metres to hundreds of kilometres and temporal scales of hours to decades. Here we present four examples from the Santa Barbara Coastal Long-term Ecological Research project that demonstrate the value of a broad temporal and spatial perspective in understanding the causes and ecological consequences of short-term local dynamics of giant kelp forests of California, USA.

Governability of Kelp Forest Small-Scale Harvesting in Iroise Sea, France

2015 ◽  
pp. 101-115 ◽  
Author(s):  
Katia Frangoudes ◽  
Clément Garineaud
Keyword(s):  
Kelp Forest ◽  
Small Scale ◽  
Iroise Sea

Hurricane damage and forest structure in Guadeloupe, French West Indies

1996 ◽  
Vol 12 (5) ◽  
pp. 663-680 ◽  
Author(s):  
Daniel Imbert ◽  
Patrick Labbé ◽  
Alain Rousteau
Keyword(s):  
Forest Structure ◽  
Mangrove Forest ◽  
Forest Cover ◽  
Deciduous Forest ◽  
Floristic Composition ◽  
Evergreen Forest ◽  
Small Scale ◽  
Forest Species ◽  
Hurricane Damage ◽  
Large Trees

ABSTRACTA comparative study of the damage caused by Hurricane Hugo on the three main types of forest in the lesser Antilles was carried out in the mangrove forest, the semi-evergreen forest and the rainforests of Guadeloupe. Hurricane impact on these forests showed at first that high canopy trees generally prevented understorey trees from heavy direct damage (shield effect). In the species-poor, structurally homogeneous stands, in the mangrove forest, species' susceptibility was the major determinant in both intensity and type of damage. Damage was heavy in places and showed a certain spatial uniformity. In the rainforest, the high structural complexity of the vegetation generally induced a great variability in the spatial distribution of damage even at a small scale. Due to the presence of tall trees, indirect damage was locally very heavy. Clumps of large trees formed resistant structures which diminished lethal damage below the main canopy (cluster effect). In such a highly structured, species-rich forest, species' susceptibility was concealed at the local scale by the prevailing influence of vertical structure. Because of its relatively rich flora but low stature, the semi-deciduous forest exhibited intermediate patterns of damage. It was concluded that floristic composition and forest structure help to explain, and to predict, hurricane damage to forest cover.

Simulating the impact of small-scale extrinsic disturbances over forest species volumetric light environment

2005 ◽  
Vol 182 (2) ◽  
pp. 113-129 ◽  
Author(s):  
P. Dubé ◽  
A. Ménard ◽  
A. Bouchard ◽  
D.J. Marceau
Keyword(s):  
Light Environment ◽  
Small Scale ◽  
Forest Species ◽  
The Impact

Influences of forest structure and landscape features on spatial variation in species composition in a palm community in central Amazonia

2014 ◽  
Vol 30 (6) ◽  
pp. 565-578 ◽  
Author(s):  
Lilian Figueiredo Rodrigues ◽  
Renato Cintra ◽  
Carolina Volkmer Castilho ◽  
Ocírio de Sousa Pereira ◽  
Tânia P. Pimentel
Keyword(s):  
Species Composition ◽  
Spatial Variation ◽  
Forest Structure ◽  
Full Range ◽  
Small Scale ◽  
Tropical Rain Forests ◽  
Ecological Gradients ◽  
Landscape Features ◽  
Palm Species ◽  
Central Amazonia

Abstract:The mechanisms that maintain palm species diversity in tropical rain forests are still debated. Spatial variation in forest structure produces small-scale environmental heterogeneity, which in turn can affect plant survival and reproductive performance. An understanding of how palms respond to variation in forest heterogeneity may help to explain the diversity and structure of their assemblages. We used multivariate ordination statistics and multiple linear models to analyse how palm assemblages are affected by forest structure and landscape features in central Amazonia. In 72 (250×4 m) forest plots distributed over an area of 64 km2, we recorded all seedling and adult palms, and measured topographic and soil variables, and components of forest structure and tree abundance. We found 16976 adults and 18935 seedlings of 46 palm species and five varieties including two morphological forms making a total of 50 botanical entities. Results show that landscape features (altitude, slope, proportions of soil sand and clay) and various components of forest structure (such as degree of forest openness, abundance of forest trees, logs and snags, and leaf litter mass), influence spatial variation in richness, abundance and species composition of palms, creating ecological gradients in palm community composition. Despite the statistically significant effects of environmental variables, most species occurred throughout the full range of the ecological gradients we studied, indicating that there is either relatively weak niche specialization in the palms, or that the competition between the species is mediated by diffuse demographic processes that cannot be evaluated only through studies of species distributions.

scholarly journals Trophic downgrading reduces spatial variability on rocky reefs

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Matthew S. Edwards ◽  
Brenda Konar
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Kelp Forest ◽  
Small Scale ◽  
Kelp Forests ◽  
Forest Communities ◽  
Opposite Pattern ◽  
Rocky Reefs ◽  
Urchin Barren ◽  
Sea Urchin Barrens

Abstract Trophic downgrading in coastal waters has occurred globally during recent decades. On temperate rocky reefs, this has resulted in widespread kelp deforestation and the formation of sea urchin barrens. We hypothesize that the intact kelp forest communities are more spatially variable than the downgraded urchin barren communities, and that these differences are greatest at small spatial scales where the influence of competitive and trophic interactions is strongest. To address this, benthic community surveys were done in kelp forests and urchin barrens at nine islands spanning 1230 km of the Aleutian Archipelago where the loss of predatory sea otters has resulted in the trophic downgrading of the region’s kelp forests. We found more species and greater total spatial variation in community composition within the kelp forests than in the urchin barrens. Further, the kelp forest communities were most variable at small spatial scales (within each forest) and least variable at large spatial scales (among forests on different islands), while the urchin barren communities followed the opposite pattern. This trend was consistent for different trophic guilds (primary producers, grazers, filter feeders, predators). Together, this suggests that Aleutian kelp forests create variable habitats within their boundaries, but that the communities within these forests are generally similar across the archipelago. In contrast, urchin barrens exhibit relatively low variability within their boundaries, but these communities vary substantially among different barrens across the archipelago. We propose this represents a shift from small-scale biological control to large-scale oceanographic control of these communities.

Reasons to strike first

2019 ◽  
Vol 42 ◽  
Author(s):  
William Buckner ◽  
Luke Glowacki
Keyword(s):  
Intergroup Conflict ◽  
Small Scale

Abstract De Dreu and Gross predict that attackers will have more difficulty winning conflicts than defenders. As their analysis is presumed to capture the dynamics of decentralized conflict, we consider how their framework compares with ethnographic evidence from small-scale societies, as well as chimpanzee patterns of intergroup conflict. In these contexts, attackers have significantly more success in conflict than predicted by De Dreu and Gross's model. We discuss the possible reasons for this disparity.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

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