scholarly journals Landscape structure shapes the diversity of tree seedlings at multiple spatial scales in a fragmented tropical rainforest

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253284
Author(s):  
Sergio Nicasio-Arzeta ◽  
Isela E. Zermeño-Hernández ◽  
Susana Maza-Villalobos ◽  
Julieta Benítez-Malvido
Keyword(s):  
Landscape Structure ◽  
Secondary Forest ◽  
Spatial Scales ◽  
Landscape Composition ◽  
Landscape Configuration ◽  
Secondary Forests ◽  
Tree Seedling ◽  
Forest Patches ◽  
Β Diversity ◽  
Α Diversity

The maintenance of seedling diversity of animal-dispersed tree species is fundamental for the structure and function of forest patches in fragmented tropical rainforests. Nonetheless, the effects of landscape structure at different spatial scales on α- and β-diversity of tree seedling communities are recently explored. Using a multi-scale approach, we assessed the relative effect of landscape composition and configuration on α- and β-diversity of animal-dispersed seedlings within 16 forest patches in the Lacandona rainforest, Mexico. We assessed these effects at 13 spatial scales (from 300 to 1500 m radius, at 100 m intervals) for three metrics of effective number of species considering α- and β-diversity. We found that α-diversity was largely affected by landscape composition and β-diversity by landscape configuration. On the one hand, the amount of secondary forest influenced α-diversity. Additionally, species richness increased in landscapes with highly aggregated forest patches. On the other hand, β-diversity was affected positively by forest fragmentation and negatively by the edge contrast of forest patches with the surrounding matrix. Our findings indicate that landscape configuration is a strong driver of seedling diversity in highly deforested rainforests. Promoting forest patches and secondary forests through payment for ecosystem services’ programs, favoring matrix quality within land-sharing schemes of smallholder agriculture and secondary forest management, and identifying restoration opportunities for assisted or unassisted natural regeneration are urgently needed for conservation of seedling diversity in human-modified tropical landscapes.

scholarly journals Landscape structure shapes tree seedlings’ diversity at multiple spatial scales in a fragmented tropical rainforest

2019 ◽  
Author(s):  
Sergio Nicasio-Arzeta ◽  
Isela E. Zermeño-Hernández ◽  
Susana Maza-Villalobos ◽  
Julieta Benítez-Malvido
Keyword(s):  
Functional Connectivity ◽  
Landscape Structure ◽  
Dominant Species ◽  
Secondary Forest ◽  
Spatial Scales ◽  
Landscape Configuration ◽  
Forest Patches ◽  
Management Actions ◽  
Β Diversity ◽  
Α Diversity

AbstractBiotic-dispersed tree seedling species are fundamental for the maintenance of the structure and function of forest patches in fragmented rainforest landscapes. Nonetheless, the effects of landscape structure and the spatial scale at which operates on seedling α- and β-diversity is unknown. Using a multi-scale approach, we assessed the relative effect of landscape composition (i.e., percentage of old-growth/secondary forest cover), configuration (i.e., aggregation/density of forest patches) and connectivity (i.e., structural and functional) on α- and β-diversity of biotic-dispersed seedlings in 16 forest patches in the Lacandona rainforest, Mexico. We assessed these effects at 13 spatial scales (from 300 to 1500 m radius, at 100 m intervals) for three α- and β-diversity orders (rare, common and dominant species). We found that patch aggregation increased species richness and reduced β-diversity of common and dominant species at similar spatial scales (500 to 600 m). Additionally, functional connectivity had a positive effect on the β-diversity of rare species in the 800 m spatial extent. These effects suggest that landscape configuration and functional connectivity sustain seedling diversity by preserving seed rain richness and the presence of large terrestrial herbivorous mammals. In contrast, the percentage of secondary forest matrix was detrimental for all α-diversity orders and the β-diversity of common and dominant species. Forthcoming conservation strategies should prevent deforestation, increase habitat amount and promote functional connectivity of forest-dependent fauna through matrix management actions.

scholarly journals Landscape structure in the northern coast of Paraná state, a hotspot for the brazilian Atlantic Forest conservation

2012 ◽  
Vol 36 (5) ◽  
pp. 961-970 ◽  
Author(s):  
Érico Emed Kauano ◽  
José Marcelo Domingues Torezan ◽  
Fernanda Cristina Gil Cardoso ◽  
Márcia Cristina Mendes Marques
Keyword(s):  
Atlantic Forest ◽  
Landscape Structure ◽  
Secondary Forest ◽  
Secondary Forests ◽  
Northern Coast ◽  
Brazilian Atlantic Forest ◽  
Landscape Matrix ◽  
Serra Do Mar ◽  
Ombrophilous Forest ◽  
Dense Ombrophilous Forest

The "Serra do Mar" region comprises the largest remnant of the Brazilian Atlantic Forest. The coast of the Paraná State is part of the core area of the "Serra do Mar" corridor and where actions for biodiversity conservation must be planned. In this study we aimed at characterizing the landscape structure in the APA-Guaraqueçaba, the largest protected area in this region, in order to assist environmental policies of this region. Based on a supervised classification of a mosaic of LANDSAT-5-TM satellite images (from March 2009), we developed a map (1:75,000 scale) with seven classes of land use and land cover and analyzed the relative quantities of forests and modified areas in slopes and lowlands. The APA-Guaraqueçaba is comprised mainly by the Dense Ombrophilous Forest (68.6% of total area) and secondary forests (9.1%), indicating a forested landscape matrix; anthropogenic and bare soil areas (0.8%) and the Pasture/Grasslands class (4.2%) were less representative. Slopes were less fragmented and more preserved (96.3% of Dense Ombrophilous Forest and secondary forest) than lowlands (71.3%), suggesting that restoration initiatives in the lowlands must be stimulated in this region. We concluded that most of the region sustains well-conserved ecosystems, highlighting the importance of Paraná northern coast for the biodiversity maintenance of the Atlantic Forest.

Effects of vegetation cover on seedling and sapling dynamics in secondary tropical wet forests in Costa Rica

2005 ◽  
Vol 22 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Juan Manuel Dupuy ◽  
Robin L. Chazdon
Keyword(s):  
Costa Rica ◽  
Tree Species ◽  
Vegetation Cover ◽  
Secondary Forest ◽  
Canopy Gaps ◽  
Canopy Gap ◽  
Control Treatment ◽  
Secondary Forests ◽  
Tree Seedling ◽  
Understorey Vegetation

We examined effects of experimental manipulations of vegetation cover on recruitment, mortality and density of seedlings (20–100 cm tall) and saplings (≥100 cm tall) of woody growth forms over a 2.5-y period. We created four treatments in each of three 15–20-y-old tropical forest stands in Costa Rica: a large canopy gap (270–350 m2), a small canopy gap (50–100 m2), understorey vegetation removal, and an unmanipulated control treatment. Creation of canopy gaps, especially large ones, increased first-year recruitment and density, as well as overall mortality of seedlings. Saplings experienced lower mortality and more prolonged gap-enhanced recruitment and density than seedlings. Removal of understorey vegetation had little or no effect on tree seedling and sapling dynamics. Recruitment and density of lianas responded only to large gaps, whereas understorey species responded to both gap treatments and to spatial heterogeneity within gaps. Tree species exhibited diverse regeneration requirements, whereas liana and understorey species were more specialized to the high and low ends of the light availability gradient, respectively. Canopy gaps provide a critical mechanism for regeneration of lianas, and canopy tree species that dominate during the early stages of secondary forest succession. The choice of management system for these secondary forests can determine the direction and rate of succession.

scholarly journals Forest aboveground biomass stock and resilience in a tropical landscape of Thailand

2019 ◽  
Author(s):  
Nidhi Jha ◽  
Nitin Kumar Tripathi ◽  
Wirong Chanthorn ◽  
Warren Brockelman ◽  
Anuttara Nathalang ◽  
...  
Keyword(s):  
Latin American ◽  
Aboveground Biomass ◽  
Laser Scanning ◽  
Secondary Forest ◽  
Recovery Process ◽  
Climatic Conditions ◽  
Forest Landscape ◽  
Secondary Forests ◽  
Forest Patches ◽  
The Mean

Abstract. Half of Asian tropical forests were disturbed in the last century resulting in the dominance of secondary forests in Southeast Asia. However, the rate at which biomass accumulates during the recovery process in these forests is poorly understood. We studied a forest landscape located in Khao Yai National Park (Thailand) that experienced strong disturbances in the last century due to clearance by swidden farmers. Combining recent field and airborne laser scanning (ALS) data, we first built a high-resolution aboveground biomass (AGB) map over 60 km2 of the forest landscape. We then used the random forest algorithm and Landsat time-series (LTS) data to classify landscape patches as non-forested versus forested on an almost annual basis from 1972 to 2017. The resulting chronosequence was then used in combination with the AGB map to estimate forest carbon recovery rates in secondary forest patches during the first 42 years of succession. The ALS-AGB model predicted AGB with an error of 14 % at 0.5-ha resolution (RMSE = 45 Mg ha−1) using the mean top-of-canopy height as a single predictor. The mean AGB over the landscape was of 291 Mg ha−1 showing a high level of carbon storage despite past disturbance history. We found that AGB recovery varies non-linearly in the first 42 years of the succession, with an increasing rate of accumulation through time. We predicted a mean AGB recovery rate of 6.9 Mg ha−1 yr−1, with a mean AGB gain of 143 and 273 Mg ha−1 after 20 and 40 years, respectively. These estimates are within the range of those reported for the well-studied Latin American secondary forests under similar climatic conditions. This study illustrates the potential of ALS data not only for scaling up field AGB measurements but also for predicting AGB recovery dynamics when combined with long-term satellite data. It also illustrates that tropical forest landscapes that were disturbed in the past are of utmost importance for the regional carbon budget and thus for implementing international programs such as REDD+.

scholarly journals Variation of plant species richness at different spatial scales

2018 ◽  
Vol 11 ◽  
pp. 49-62 ◽  
Author(s):  
Khem Raj Bhattarai
Keyword(s):  
Species Richness ◽  
Spatial Scales ◽  
Local Scale ◽  
Explanatory Variables ◽  
Local Species Richness ◽  
Β Diversity ◽  
Historical Processes ◽  
Α Diversity ◽  
Local Species ◽  
Broad Scale

 It is now realized that the variation in species richness is influenced by spatial and temporal scales. Pattern and scale are a central focus in ecology and biogeography. The species richness relationship depends on the scale of study and their correlated factors. The broad objective of this review is to elucidate how different scales are correlated with different explanatory variables to generate patterns of species richness. Addressing the problem of scale has both fundamental and applied importance in understanding variation in species richness along gradients. The understanding of pattern, its causes, and consequences is central to our understanding of processes such as succession, community development, and the spread and persistence of species. According to the hierarchical theory of species diversity there are mainly three categories of scales: local, landscape and regional. The local species richness or α-diversity is the diversity of individual stands. The β-diversity or species change is turnover between two elevational bands or between two plots or two sites. The regional or γ-diversity is the total richness of whole mountains or study systems and it has a combined influence from α- and β-diversity. The local species richness is affected by both local-scale processes (e.g., internal interactions) and broad-scale processes (e.g., evolutionary). Different explanatory variables according to the scales of study are necessary to explain variation at different spatial scales. Local factors (e.g., disturbance, grazing and tree cover) have been used to detect variation at a local scale. Generally, topographical factors are used to detect variation in species richness at a landscape scale; whereas climate, water-energy dynamics and historical processes are used to detect variation at a regional scale. However, it is not easy to separate strictly one scale from other because there is no clear boundary between them. The study of the whole elevation gradient from tropical to alpine zone or long latitude is a broad-scale study. The intermediate scale is a study on a local mountain, which covers the subtropical to warm temperate zones. To explain patterns of species richness, a pluralistic body of hypotheses, which incorporates historical, biological and climatic factors, is needed. This is depicted by the strong relationship between climate, biological interactions, and historical processes in influencing variation in species richness at different spatial scales.Botanica Orientalis – Journal of Plant Science (2017) 11: 49–62

scholarly journals Landscape Structure Effects on Bee and Wasp Assemblages in a Semiarid Buffer Zone

2019 ◽  
Vol 76 ◽  
pp. 1-17 ◽  
Author(s):  
Lilian Maria Araujo Flores ◽  
Lorenzo Roberto Sgobaro Zanette ◽  
Danilo Boscolo ◽  
Francisca Soares Araújo
Keyword(s):  
Landscape Structure ◽  
Landscape Heterogeneity ◽  
Buffer Zone ◽  
Spatial Arrangement ◽  
Landscape Composition ◽  
Landscape Configuration ◽  
Resource Limited ◽  
Conservation Actions ◽  
Landscape Units ◽  
Vegetation Loss

Understanding the effects of anthropogenic changes on groups that perform key ecosystem services, such as pollination and pest control, is essential for conservation and maintenance of these groups in landscapes. We aimed to understand how landscape heterogeneity and the natural vegetation loss affect the diversity of bees, wasps and their parasitoids in a resource limited semiarid environment. We sampled bees and wasps that nest in pre-existing cavities in 20 landscapes, for two years, in Ubajara National Park, in northeastern of Brazil. We recorded eleven species of bees, nine of wasps and six of parasitoids in 657 trapnests. Landscape heterogeneity had different effects on bees, wasps and their parasitoids. Landscape configuration had stronger effect than composition. Bee abundance decreased according to the complexity of the spatial arrangement of landscape units, while wasp abundance increased. Our study shows that in semiarid regions some species may have different responses to landscape structure from those found in other regions. The spatial patterns described here have important implications for conservation of these essential biological groups, indicating that conservation actions for these groups should associate both landscape composition and configuration to increase the provision of resources and to facilitate the access to resources throughout the year.

scholarly journals Nematode diversity patterns at different spatial scales in bathyal sediments of the Mediterranean Sea

2013 ◽  
Vol 10 (8) ◽  
pp. 5465-5479 ◽  
Author(s):  
S. Bianchelli ◽  
C. Gambi ◽  
M. Mea ◽  
A. Pusceddu ◽  
R. Danovaro
Keyword(s):  
Mediterranean Sea ◽  
Deep Sea ◽  
Spatial Scales ◽  
High Turnover ◽  
Trophic Conditions ◽  
Bathymetric Range ◽  
Β Diversity ◽  
Α Diversity ◽  
Nematode Diversity ◽  
The Mediterranean

Abstract. Understanding biodiversity patterns and how they are driven at different spatial scales is a crucial issue in ecological studies. This is particularly evident for the deep sea, the largest biome of the biosphere, where information on the scales of spatial variation is very scant. Here, we investigated deep-sea nematodes species richness, turnover and functional diversity, and life strategies at different spatial scales (from local to macro-regional) to identify the factors that shape regional (γ) and macro-regional (ε) deep-sea diversity. This study was conducted in several deep-sea habitats (canyons, open slopes, deep-water corals, and bathyal plains) over > 2000 km across the whole Mediterranean Basin, at a bathymetric range comprised between ca. 600 and 1300 m. Our results indicate that the patterns of local (α) diversity across the deep Mediterranean follow the gradients of the trophic conditions, which decrease from the western to the eastern basins. For all of the sites and habitats, the α diversity is generally low. Conversely, the turnover diversity changes significantly among habitats (β diversity) and between regions (δ diversity), showing values of dissimilarity (based on species presence/absence matrixes) between 59 and 90% for β diversity and between 81 and 89% for δ diversity. This suggests that patterns and values of γ and ε diversities in the deep Mediterranean Sea are related to turnover diversity among habitats and between regions (β and δ diversities), rather than to the local biodiversity (α diversity). These results indicate also that the differences in β and δ diversities are even more important than those in α diversity for the comprehension of the drivers of biodiversity in the deep Mediterranean Sea. We conclude that the presence of different habitats and gradients in environmental conditions, by promoting a high turnover diversity across the Mediterranean Sea, may play a crucial role in the levels of γ diversity of deep-sea nematodes.

scholarly journals Macrofauna communities across a seascape of seagrass meadows: environmental drivers, biodiversity patterns and conservation implications

2021 ◽  
Author(s):  
Iván F. Rodil ◽  
Andrew M. Lohrer ◽  
Karl M. Attard ◽  
Judi E. Hewitt ◽  
Simon F. Thrush ◽  
...  
Keyword(s):  
Habitat Management ◽  
Plant Biomass ◽  
Spatial Scales ◽  
Environmental Drivers ◽  
Kelp Forests ◽  
Natural Occurrence ◽  
Seagrass Meadows ◽  
Β Diversity ◽  
Α Diversity ◽  
Macrofauna Communities

AbstractSimilar to other coastal biogenic habitats (e.g. tidal marshes, kelp forests, mangroves and coral reefs), a key function of seagrass meadows is the enhancement of biodiversity. Variability at multiple spatial scales is a driver of biodiversity, but our understanding of the response of macrofauna communities to variability of seagrass meadows is limited. We examined the macrofauna community structure (abundance and biomass) and diversity patterns (α- and β-diversity) across a seascape gradient of eleven seagrass meadows differing in the number, composition and density of plant species. The variability of the macrobenthic communities was regulated by a combination of sedimentary (mainly for the infauna) and macrophyte (mainly for the epifauna) predictors. We demonstrate that the natural occurrence of drifting algae trapped in the aboveground complexity of the meadows benefits seagrass macrofauna. Seagrass-associated macrofauna showed a clear increase in abundance and α-diversity metrics with increasing habitat complexity attributes (i.e. shoot density, plant biomass and canopy height). Furthermore, partitioning of β-diversity (i.e. the variation of species composition between sites) implied the replacement of some species by others between sites (i.e. spatial turnover) instead of a process of species loss (or gain) from site to site (i.e. nestedness). Therefore, the enhancement of macrofauna diversity across an increasing gradient of seagrass complexity, and the dominance of the turnover component suggest that devoting conservation efforts on many different types of meadows, including the less diverse, should be a priority for coastal habitat-management.

Landscape Configuration Influences Species Occupancy Over Multiple Spatial Scales: A Case Study On Tawny Owl

2021 ◽  
Author(s):  
Jakob Wildraut ◽  
Marco Basile
Keyword(s):  
Spatial Scale ◽  
Spatial Scales ◽  
Coniferous Forest ◽  
Landscape Configuration ◽  
Species Occurrence ◽  
Forest Patches ◽  
Tawny Owl ◽  
Generalist Species ◽  
Multiple Spatial Scales ◽  
Time Substitution

ABSTRACT Landscape configuration can influence the distribution of species across multiple spatial scales. The primary factors related to this process are connectivity, the size and position of habitat patches, and edge effects. These factors together determine the overall fragmentation of a landscape, which in turn influences species occurrence. Although some species show a negative response to fragmentation, others benefit from it. Potential effects may act over multiple spatial scales, possibly with contrasting effects on species occurrence. We chose the Tawny Owl (Strix aluco), a ubiquitous and generalist species, to study the influence of fragmentation on species occurrence and to identify relevant landscape metrics, using multi-scale hierarchical modelling. Between 2016 and 2018, we recorded Tawny Owls on 64 sampling sites located in a forested landscape. We used a space-for-time substitution in the framework of occupancy modelling to assess Tawny Owl responses to landscape fragmentation. We found that the Tawny Owl is widespread in the study area. Its distribution across the landscape (larger spatial scale) was related to a heterogeneous configuration of forest patches, while high connectivity of coniferous forest influenced its occurrence at a smaller spatial scale (sites). Overall, the Tawny Owl prefers landscapes with well-connected forest patches and an uneven patch distribution in the surrounding area.

scholarly journals Turnover diversity drives large-scale biodiversity patterns in bathyal sediments of the Mediterranean Sea

2012 ◽  
Vol 9 (12) ◽  
pp. 17819-17853 ◽  
Author(s):  
S. Bianchelli ◽  
C. Gambi ◽  
M. Mea ◽  
A. Pusceddu ◽  
R. Danovaro
Keyword(s):  
Mediterranean Sea ◽  
Deep Sea ◽  
Large Scale ◽  
Spatial Scales ◽  
High Turnover ◽  
Trophic Conditions ◽  
Biodiversity Patterns ◽  
Β Diversity ◽  
Α Diversity ◽  
Nematode Diversity

Abstract. Understanding biodiversity patterns and how they are driven at different spatial scales is a crucial issue in ecological studies. This is particularly evident for the deep sea, the largest biome of the biosphere, where information on the scales of spatial variation is very scant. Here, we investigated deep-sea nematodes species richness, turnover and functional diversity, and life strategies at different spatial scales (from local to macro-regional) to identify the factors that shape regional (γ) and macro-regional (ϵ) deep-sea diversity. This study was conducted in several deep-sea habitats (canyons, open slopes, deep-water corals, and bathyal plains) over > 2000 km across the whole Mediterranean basin, at a fixed depth of ca. 1000 m. Our results indicate that the patterns of local (α) diversity across the deep Mediterranean follow the gradients of the trophic conditions, which decrease from the Western to the Eastern basins. For all of the sites and habitats, the α-diversity is generally low. Conversely, the turnover diversity changes significantly among habitats (β-diversity) and between regions (δ-diversity), showing values of dissimilarity (based on species presence/absence) between 59% and 90% for β-diversity and between 81% and 89% for δ-diversity. This suggests that patterns and values of regional (γ) and macro-regional (ϵ) diversity in the deep Mediterranean Sea are related to turnover diversity among habitats and between regions (β- and δ-diversity), rather than to the local biodiversity (α-diversity). These results indicate that the differences in β-diversity and δ-diversity are even more important than those for the α-diversity for the understanding of the drivers of biodiversity in the deep Mediterranean Sea. These data also allow us to conclude that habitat heterogeneity (and type) and gradients in environmental conditions, by promoting a high turnover diversity across the deep Mediterranean Sea, are crucial players for the nematode diversity levels.

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