Inferring savannah–rainforest boundary dynamics from vegetation structure and composition: a case study in New Caledonia

2013 ◽  
Vol 61 (2) ◽  
pp. 128 ◽  
Author(s):  
Thomas Ibanez ◽  
Jérôme Munzinger ◽  
Cédric Gaucherel ◽  
Thomas Curt ◽  
Christelle Hély
Keyword(s):  
Vegetation Structure ◽  
Temporal Dynamics ◽  
New Caledonia ◽  
Fire Regime ◽  
Direct Consequence ◽  
Forest Tree ◽  
Forest Edge ◽  
Forest Fragments ◽  
Melaleuca Quinquenervia ◽  
Forest Expansion

A direct consequence of deforestation and forest fragmentation in the tropics is the increased importance of boundaries between forest fragments and savannahs. These boundaries are critical zones for understanding the dynamics of savannahs and forests. In the present study, the spatio-temporal dynamics of a savannah–forest boundary in New Caledonia were inferred from the analyses of vegetation structure and composition along three transects. Remnant savannah trees (Melaleuca quinquenervia (Cav.) S.T.Blake) in the forest part of the transect indicated that the forest edge has shifted towards savannah. This margin-forest expansion hypothesis was reinforced by gradual changes from the forest edge to the forest core in species composition (e.g. increase in the frequency of forest-core species) and population structure (e.g. increase in forest tree-stem diameter). However, sharp changes at the forest edge (mainly the increased frequency of small forest trees) suggested that forest expansion has likely been stopped. This suggested that different phases may alternate in the dynamics of savannah–forest boundaries, including stable phases where the boundary does not move, and unstable phases where the boundary moves or expands towards savannah or forest. Variations in the fire regime as a result of the interactions among climate, fire use by humans and vegetation are likely to drive these dynamics.

scholarly journals Edge creation changes the timing and intensity of phenological reproductive patterns and species activities in forest tree communities

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
João Pedro Costa Elias ◽  
Driélli Carvalho Vergne ◽  
Mariane Patrezi Zanatta ◽  
Caroline Cambraia Furtado Campos ◽  
Flavio Nunes Ramos
Keyword(s):  
Tree Species ◽  
Forest Tree ◽  
Forest Edge ◽  
Forest Fragments ◽  
Monthly Basis ◽  
Reproductive Patterns ◽  
Forest Interior ◽  
Phenological Changes ◽  
Habitat Loss And Fragmentation ◽  
Tree Communities

Abstract Environmental characteristics are among the most important triggers and regulators of plant phenophases, so that the abiotic and biotic changes driven by habitat loss and fragmentation can result in alterations of plant phenological patterns. We investigated whether forest edge and interior have differences in phenological pattern of tree communities. We followed the reproductive phenologies of tree communities in seven forest fragments on a monthly basis for two years (in 200 m² edge and interior plots per fragment). We sampled a total of 0.28 ha of anthropic forest fragments, comprising 313 trees (180 in edge, 133 in interior) belonging to 103 species and 34 families. Our results evidenced reproductive phenological changes between edge and interior tree communities, with: (i) phenological activities differing temporally between the two habitats (edge and forest interior) in all tree communities; (ii) greater phenological intensity at the forest edge than in the forest interior among tree species common to both habitats; (iii) more tree species showed phenological activity at the forest edge in 2010 and interior in 2011, when considering only those exclusive to each habitat. Habitat fragmentation can therefore alter microenvironmental characteristics and influence biologic processes, including the reproductive phenologies of trees, through edge formation.

The role of short-term weather conditions in temporal dynamics of fire regime features in mainland Spain

2019 ◽  
Vol 241 ◽  
pp. 575-586 ◽  
Author(s):  
Adrián Jiménez-Ruano ◽  
Marcos Rodrigues Mimbrero ◽  
W. Matt Jolly ◽  
Juan de la Riva Fernández
Keyword(s):  
Temporal Dynamics ◽  
Fire Regime ◽  
Weather Conditions ◽  
Short Term

scholarly journals Forschung zur Vielfalt, vielfältige Forschung: Ziele und Wege der Forstgenetik | Research on diversity, diverse research: objectives and approaches in forest genetics

2001 ◽  
Vol 152 (5) ◽  
pp. 162-168 ◽  
Author(s):  
Reiner Finkeldey
Keyword(s):  
Genetic Resources ◽  
Genetic Information ◽  
Temporal Dynamics ◽  
Forest Tree ◽  
Gene Marker ◽  
Adaptive Potential ◽  
Forest Genetics ◽  
Marker Loci ◽  
Forest Genetic ◽  
Forest Genetic Resources

The genetic information about forest trees is not only of crucial importance for the yield of forestry production systems,but also for determining the evolutionary adaptive potential of tree populations. Thus, the stability of forest ecosystems depends on the sustainable management of forest genetic resources. In this context, tree breeding and conservation of forest genetic resources are mentioned as main applications of research in forest genetics. Genetic inventories are conducted in order to observe the spatial distribution of genetic information at gene marker loci. Such studies allow us to elucidate the evolutionary history of populations and, thus, to draw conclusions about their evolutionary adaptability. Results of a genetic inventory of oak (Quercus spp.) populations native to Switzerland are presented, and their significance for the characterization of genetic systems and adaptive potential is discussed. Future research into forest genetics should aim at improving our understanding of the relationship between variation at biochemical and molecular marker loci and adaptive processes in forest tree populations. The temporal dynamics of genetic structures of forest tree populations as a consequence of anthropogenic environmental change is another important topic of forest genetics in particular for the conservation of rare species.

scholarly journals Patterns of fish utilisation in a tropical Indo-Pacific mangrove-coral seascape, New Caledonia

2018 ◽  
Author(s):  
A Dubuc ◽  
N. Waltham ◽  
R. Baker ◽  
C. Marchand ◽  
M. Sheaves
Keyword(s):  
Fish Assemblages ◽  
New Caledonia ◽  
Lunar Cycle ◽  
Forest Edge ◽  
Temporal Variations ◽  
Conservation Strategies ◽  
Small Scale ◽  
Mangrove Forests ◽  
Species Specific ◽  
Main Component

AbstractMangrove forests are important habitats for fish. However, their utilisation by fish, and the specific values they confer, are still not fully understood. This study describes how fish use mangrove forests in an Indo-Pacific mangrove-coral reef seascape. Sampling was conducted using underwater video cameras (UVCs) to describe spatial and temporal variations in fish assemblages across a small-scale (~ 2.5 km2) system, and over the tidal and lunar cycle. UVCs were deployed in the two main component habitats of mangrove forests: at the mangrove forest edge, and inside the forest (5 m from the forest edge), to establish patterns of utilisation of fish across the tidal and lunar cycle. Proximity to coral reefs had a strong influence on the mangrove fish community, as most fish recorded were reef-associated. Juveniles of 12 reef species were observed, including two species classified as vulnerable on the IUCN list, and one endemic species. Fish assemblages on the mangrove edge differed significantly from those inside the forest. Most fish utilised the forest edge, with few species making regular use of in-forest habitats, supporting the contention that most fish species remain on the edge and potentially retreat into the forest for opportunistic feeding, or when threatened by larger predators. Species-specific patterns of utilisation varied across the tidal and lunar cycle. Small differences in depth profiles and substrate across the small-scale system had a significant effect on fish assemblages, highlighting the importance of accounting for spatial heterogeneity in these factors. These data provide important information for managers to implement adequate conservation strategies that include broader interconnected habitat mosaics.

Fire and open ecosystems

2019 ◽  
pp. 97-120
Author(s):  
William J. Bond
Keyword(s):  
Vegetation Structure ◽  
Open Systems ◽  
Fire Regime ◽  
Alternative Stable States ◽  
Fire Regimes ◽  
Fire Effects ◽  
Emergent Property ◽  
Stable States ◽  
Mosaic Landscapes ◽  
Patterns And Processes

Can fire account for the widespread occurrence of open ecosystems? This chapter explores fire as a major consumer shaping vegetation in diverse regions worldwide. The concept of fire regime helps explain the diverse influences of fire on vegetation structure. Fire regimes select compatible growth forms from the species pool. These, in turn, create the fuel which in large part determines the fire regime. Experimental evidence can show whether fire is a major determinant of vegetation structure or merely an emergent property of ecosystems determined by climate and soils. Whether fires consume closed forests or stop at their margins will determine the dominant vegetation in mosaic landscapes. A mechanistic framework for analysing processes influencing fire effects on the boundary is introduced with examples. Pyrophilic open systems in mosaics with pyrophobic closed forests have been considered as examples of Alternative Stable States. Recent evidence for the patterns and processes expected by ASS theory are discussed.

Edge Effects on the Epiphytic Lichen Flora of Picea Abies in Middle Boreal Finland

2000 ◽  
Vol 32 (4) ◽  
pp. 387-398 ◽  
Author(s):  
Laura Kivistö ◽  
Mikko Kuusinen
Keyword(s):  
Species Diversity ◽  
Picea Abies ◽  
Forest Edge ◽  
Lichen Species ◽  
Forest Fragments ◽  
Epiphytic Lichen ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Forest Margin ◽  
Lichen Flora

AbstractThe edge effect of large clear-cuts on the epiphytic lichen flora of Picea abies in old-growth forest fragments was studied at three south-exposed and four north-exposed forest clear-cut edges in middle boreal Finland. The sampling of the species cover on trunk bases was carried out along four transects parallel to the forest margin: (1) at the forest margin, (2) 10 m from the margin, (3) 20 m from the margin and (4) 50 m from the margin. In addition, control trees were sampled > 100 m from nearest edge. Our results showed that the epiphytic lichen species diversity was lower at the forest margin than in the forest interior for sunny south-facing edges, while the species diversity in north-exposed edges was independent of the distance from the forest margin. The cover of a common and abundant lichen species, Parmeliopsis ambigua, was slightly higher at the forest edge and decreased inside the forest for both south-exposed and north-exposed edges.

Spatial fuel data products of the LANDFIRE Project

2009 ◽  
Vol 18 (3) ◽  
pp. 250 ◽  
Author(s):  
Matthew C. Reeves ◽  
Kevin C. Ryan ◽  
Matthew G. Rollins ◽  
Thomas G. Thompson
Keyword(s):  
Bulk Density ◽  
Vegetation Structure ◽  
Fire Regime ◽  
Fire Behavior ◽  
The United States ◽  
Surface Fire ◽  
Spatial Coverage ◽  
Data Products ◽  
Fuel Models ◽  
Canopy Bulk Density

The Landscape Fire and Resource Management Planning Tools (LANDFIRE) Project is mapping wildland fuels, vegetation, and fire regime characteristics across the United States. The LANDFIRE project is unique because of its national scope, creating an integrated product suite at 30-m spatial resolution and complete spatial coverage of all lands within the 50 states. Here we describe development of the LANDFIRE wildland fuels data layers for the conterminous 48 states: surface fire behavior fuel models, canopy bulk density, canopy base height, canopy cover, and canopy height. Surface fire behavior fuel models are mapped by developing crosswalks to vegetation structure and composition created by LANDFIRE. Canopy fuels are mapped using regression trees relating field-referenced estimates of canopy base height and canopy bulk density to satellite imagery, biophysical gradients and vegetation structure and composition data. Here we focus on the methods and data used to create the fuel data products, discuss problems encountered with the data, provide an accuracy assessment, demonstrate recent use of the data during the 2007 fire season, and discuss ideas for updating, maintaining and improving LANDFIRE fuel data products.

Distance effect from cloud forest fragments on plant community structure in abandoned pastures in Veracruz, Mexico

2006 ◽  
Vol 22 (4) ◽  
pp. 431-440 ◽  
Author(s):  
Miguel Angel Muñiz-Castro ◽  
Guadalupe Williams-Linera ◽  
José María Rey Benayas
Keyword(s):  
Species Richness ◽  
Vegetation Structure ◽  
Forest Restoration ◽  
Cloud Forest ◽  
Distance Effect ◽  
Basal Area ◽  
Woody Species ◽  
Primary Forest ◽  
Forest Fragments ◽  
Forest Region

Secondary succession was studied in a Mexican cloud forest region along a chronosequence of 15 abandoned pastures (0.25–80 y). Our objective was to determine the effects of distance from the forest border on successional vegetation structure and woody species richness along the chronosequence. Vegetation structure similar to that of mature forests recovered over 40–50 y, both close to (0–10 m) and away from (40–50 m) the border. Total woody species richness was similar for both distances but species composition differed significantly. When primary forest species were analysed separately, basal area, height, abundance and richness were all significantly higher close to the forest border. Primary species such as Quercus spp. (barochorous-synzoochorous) and Carpinus caroliniana (anemochorous) had lower basal area, density and height away from the border than close to it. Secondary species such as Lippia myriocephala (anemochorous) and Myrsine coriacea (endozoochorous) did not differ in their rate of colonization between distances. The limitation of seed dispersal and establishment for primary woody species away from forest borders suggests that propagules need to be introduced to accelerate forest restoration.

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