scholarly journals Phenology of Tropical Birds in Peninsular Malaysia: Effects of Selective Logging and Food Resources

The Auk ◽  
2007 ◽  
Vol 124 (3) ◽  
pp. 945-961
Author(s):  
Charlotte A-M. Yap ◽  
Navjot S. Sodhi ◽  
Kelvin S-H. Peh
Keyword(s):  
Forest Structure ◽  
Peninsular Malaysia ◽  
Food Resources ◽  
Selective Logging ◽  
Food Abundance ◽  
Forest Types ◽  
Feeding Guild ◽  
Bird Abundance ◽  
Regeneration Time ◽  
Understory Birds

AbstractThe increasing prevalence of selective logging in Southeast Asian tropical rainforests compels much-needed studies to examine its effects on the vital life-cycle events of their resident understory birds, which are particularly sensitive to such degradation. Food abundance, which can be an important factor in avian phenology, may be affected by selective logging. Therefore, studies that compare food abundance and breeding and molting occurrence simultaneously at the same sites are important for the ecological monitoring of such logging regimes. Using bimonthly mist netting in two rainforest areas in Peninsular Malaysia, we assessed the breeding and molting occurrence and diets of understory birds and compared the abundance of food resources in unlogged forests and forests that had been selectively logged 30 years before. Our study revealed no differences between forest types in overall understory-resident bird abundance; comparative species richness; feeding-guild composition; breeding and molting occurrence and temporal variation; or arthropod, fruit, and flower abundance. The similarity in food resources could account for the similarity in avian phenological characteristics between forest types. Increased breeding corresponded with increased food abundance at the feeding-guild level, and dietary data supported these findings. Breeding cycles of sensitive indicator groups such as understory resident birds are likely to depend on food abundance and forest structure and, thus, on selective logging. Our observation of undiminished avian breeding and molting occurrence in selectively logged forests is an encouraging indication of their conservation potential. However, we emphasize that differences in selective logging practices could affect the forest structure and avifauna differently. Setting thresholds for extraction and regeneration time and subscribing to minimum-impact methods that reduce collateral damage are essential if selectively logged areas are to maintain most of their initial biodiversity.Fenología de Aves Tropicales en Malasia Peninsular: Efectos de la Tala Selectiva y los Recursos Alimenticios

Community characteristics of forest understory birds along an elevational gradient in the Horn of Africa: A multi-year baseline

The Condor ◽  
2021 ◽  
Author(s):  
Kyle D Kittelberger ◽  
Montague H C Neate-Clegg ◽  
Evan R Buechley ◽  
Çağan Hakkı Şekercioğlu
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Survival Rates ◽  
Elevational Gradient ◽  
Forest Understory ◽  
Bird Abundance ◽  
Tropical Mountains ◽  
Demographic Rates ◽  
Understory Birds ◽  
Over Time

Abstract Tropical mountains are global hotspots for birdlife. However, there is a dearth of baseline avifaunal data along elevational gradients, particularly in Africa, limiting our ability to observe and assess changes over time in tropical montane avian communities. In this study, we undertook a multi-year assessment of understory birds along a 1,750 m elevational gradient (1,430–3,186 m) in an Afrotropical moist evergreen montane forest within Ethiopia’s Bale Mountains. Analyzing 6 years of systematic bird-banding data from 5 sites, we describe the patterns of species richness, abundance, community composition, and demographic rates over space and time. We found bimodal patterns in observed and estimated species richness across the elevational gradient (peaking at 1,430 and 2,388 m), although no sites reached asymptotic species richness throughout the study. Species turnover was high across the gradient, though forested sites at mid-elevations resembled each other in species composition. We found significant variation across sites in bird abundance in some of the dietary and habitat guilds. However, we did not find any significant trends in species richness or guild abundances over time. For the majority of analyzed species, capture rates did not change over time and there were no changes in species’ mean elevations. Population growth rates, recruitment rates, and apparent survival rates averaged 1.02, 0.52, and 0.51 respectively, and there were no elevational patterns in demographic rates. This study establishes a multi-year baseline for Afrotropical birds along an elevational gradient in an under-studied international biodiversity hotspot. These data will be critical in assessing the long-term responses of tropical montane birdlife to climate change and habitat degradation.

scholarly journals Deriving Stand Structural Complexity from Airborne Laser Scanning Data—What Does It Tell Us about a Forest?

2020 ◽  
Vol 12 (11) ◽  
pp. 1854
Author(s):  
Dominik Seidel ◽  
Peter Annighöfer ◽  
Martin Ehbrecht ◽  
Paul Magdon ◽  
Stephan Wöllauer ◽  
...  
Keyword(s):  
Forest Structure ◽  
Laser Scanning ◽  
Structural Complexity ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Stand Age ◽  
Box Dimension ◽  
Forest Types ◽  
3D Point Clouds ◽  
Airborne Laser

The three-dimensional forest structure is an important driver of several ecosystem functions and services. Recent advancements in laser scanning technologies have set the path to measuring structural complexity directly from 3D point clouds. Here, we show that the box-dimension (Db) from fractal analysis, a measure of structural complexity, can be obtained from airborne laser scanning data. Based on 66 plots across different forest types in Germany, each 1 ha in size, we tested the performance of the Db by evaluating it against conventional ground-based measures of forest structure and commonly used stand characteristics. We found that the Db was related (0.34 < R < 0.51) to stand age, management intensity, microclimatic stability, and several measures characterizing the overall stand structural complexity. For the basal area, we could not find a significant relationship, indicating that structural complexity is not tied to the basal area of a forest. We also showed that Db derived from airborne data holds the potential to distinguish forest types, management types, and the developmental phases of forests. We conclude that the box-dimension is a promising measure to describe the structural complexity of forests in an ecologically meaningful way.

scholarly journals Vascular Epiphytic Diversity in a Neotropical Transition Zone Is Driven by Environmental and Structural Heterogeneity

2019 ◽  
Vol 12 ◽  
pp. 194008291988220 ◽  
Author(s):  
Edilia de la Rosa-Manzano ◽  
Glenda Mendieta-Leiva ◽  
Antonio Guerra-Pérez ◽  
Karla María Aguilar-Dorantes ◽  
Leonardo Uriel Arellano-Méndez ◽  
...  
Keyword(s):  
Species Richness ◽  
Transition Zone ◽  
Forest Structure ◽  
Forest Type ◽  
Species Turnover ◽  
Cloud Forest ◽  
Size Variation ◽  
Alpha Diversity ◽  
Forest Types ◽  
Semideciduous Forest

Vascular epiphytes contribute significantly to tropical diversity. Research on the factors that determine vascular epiphytic diversity and composition in tropical areas is flourishing. However, these factors are entirely unknown in tropical-temperate transition zones, which represent the distribution limit of several epiphytic species. We assessed the degree to which climatic and structural variables determine the diversity of vascular epiphytic assemblages (VEAs) in a transition zone in Mexico: the El Cielo Biosphere Reserve. We found 12,103 epiphytic individuals belonging to 30 species and 15 genera along a climatic gradient from 300 to 2,000 m a.s.l. Bromeliaceae and Orchidaceae were the most species-rich families. Forests along the windward slope of the Sierra Madre Oriental (semideciduous forest and tropical montane cloud forest) had higher species richness than forests along the leeward slope (pine-oak forest and submontane scrub). Species richness was largely determined by seasonality and, to a lesser degree, by forest structure, whereas abundance was mainly determined by host tree size. Variation in VEAs composition was largely explained by climatic variables, whereas forest structure was not as important. VEAs differed among forest types and slopes in terms of taxonomic and functional composition. For example, certain bromeliad indicator species reflected differences between slopes. Although within-tree epiphytic species richness (alpha diversity) was low in this transition zone relative to other habitats, species turnover among forest types (beta diversity) was high. These findings suggest that each forest type makes a unique and important contribution to epiphytic diversity in this transition zone.

Forest developmental trajectories in mountain pine beetle disturbed forests of Rocky Mountain National Park, Colorado

2011 ◽  
Vol 41 (4) ◽  
pp. 782-792 ◽  
Author(s):  
Matthew Diskin ◽  
Monique E. Rocca ◽  
Kellen N. Nelson ◽  
Carissa F. Aoki ◽  
W.H. Romme
Keyword(s):  
Forest Structure ◽  
National Park ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Developmental Trajectories ◽  
Rocky Mountain ◽  
Rocky Mountain National Park ◽  
Forest Types ◽  
Mountain Pine ◽  
Pine Beetle

A mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic has caused widespread mortality of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees across western North America,. We characterized the initial effects of beetle-induced mortality on forest structure and composition in Rocky Mountain National Park, Colorado. In 2008, we surveyed stand structure and tree species composition across lodgepole pine dominated forests in the western portion of the Park. We defined five lodgepole pine forest types to describe variability in pre-epidemic forest conditions. This forested landscape appears to be resilient to the effects of the beetle. Surviving trees, including both canopy trees and saplings, were plentiful in most of the post-epidemic forests, even after accounting for anticipated future mortality. Subalpine fir (Abies lasiocarpa (Hook.) Nutt.), Engelmann spruce (Picea engelmannii Parry ex Engelm.), and aspen (Populus tremuloides Michx.) had modestly higher relative abundances after the epidemic. Lodgepole pine remained the dominant species on approximately 85% of the landscape. The impact of the outbreak on forest structure and composition varied considerably among the five forest types, suggesting that post-epidemic forest developmental trajectories will vary according to pre-outbreak stand characteristics. Active management efforts to regenerate lodgepole pine forests, e.g., tree planting, will likely not be necessary on this landscape.

scholarly journals The implications of selective logging and forest fragmentation for the conservation of avian diversity in evergreen forests of south-west Ghana

2005 ◽  
Vol 15 (1) ◽  
pp. 27-52 ◽  
Author(s):  
LARS H. HOLBECH
Keyword(s):  
Forest Fragmentation ◽  
Management Practices ◽  
Selective Logging ◽  
Global Perspective ◽  
Bird Diversity ◽  
Line Transect ◽  
Tropical Forestry ◽  
Regeneration Time ◽  
Conservation Implications ◽  
South West

The urgent global objective of developing sustainable tropical forestry management practices, which also target biodiversity conservation, requires rapid comparative studies that address both biogeography and logging practices. This paper examines avifaunal implications (focusing on species diversity and composition) of forest fragmentation and selective logging, by comparing 15 selected reserved forests in south-west Ghana. The regeneration time since last logging varied from 0 (logging continuing) to 21 years, with one unlogged site as control. Extraction levels ranged between 0.20 and 3.75 trees per ha (mean 0.90). Bird sampling involved understorey mist-netting and standardized line-transect walks, which respectively accumulated 8,348 captures and 22,452 single records of 147 species. Mist-net data showed that understorey bird diversity was positively correlated with logging intensity up to c. 3 trees per ha, reflecting increased influx of open-land species and a persistence of forest obligates during the first 5 years after logging. The overall abundance of forest interior species tended to decrease 5–10 years after logging, but recovered fairly well thereafter. Canopy birds were generally more logging-resilient. Rare forest obligates with high conservation importance were found to be equally abundant in virgin and logged, large forests, whereas these birds were poorly represented in small heavily logged forests. The results are compared with findings from other regions, and conservation implications and constraints are discussed in a global perspective. Finally, recommendations on size-related sustainable extraction levels and regeneration time are presented for the Upper Guinea Forest.

scholarly journals Disentangling the effects of past logging and ongoing cryptic anthropogenic disturbance on vegetation structure and composition in Himalayan Foothills, India

2021 ◽  
Author(s):  
Monica Kaushik ◽  
Sutirtha Dutta ◽  
Gopal S. Rawat ◽  
Pratap Singh ◽  
Dhananjai Mohan
Keyword(s):  
Vegetation Structure ◽  
Forest Resources ◽  
Selective Logging ◽  
Forest Recovery ◽  
Forest Types ◽  
Regeneration Rate ◽  
Mature Forest ◽  
Management Interventions ◽  
Himalayan Foothills ◽  
Adult Trees

AbstractMost tropical forests have undergone commercial logging. Even where logging has ceased, subsistence harvest of forest resources often persists especially in South-East Asia. Understanding of impacts of frequent forest resources extraction in areas recovering from past selective logging would be essential for designing the appropriate management interventions.We studied the impacts of current chronic anthropogenic disturbances (hereafter CAD) and past selective logging on vegetation structure, diversity, and regeneration, and the invasion of a non-native shrub, Lantana camara, in three major forest types in the Himalayan foothills, India. We analyzed field data on intensity of CAD and vegetation variables, collected from 269 stratified random plots, using ordination and generalized linear (mixed) modeling approaches.Our results, based on 2758 adult trees of 54 species, showed that forest types differed in disturbance regimes depending on protection level and availability of fodder tree species. Intensity of CAD depended on proximity to settlements (for livestock related disturbances). Whereas selective logging, including firewood collection, was associated with land protection status. Selective logging reduced the extent of mature forest but facilitated regeneration, thereby promoting secondary forest features such as tree density and canopy cover. In contrast, the interaction between lopping and selective logging was negatively associated with regeneration. Past logging facilitated L. camara invasion in Dry and Hill forests but not in Moist forest. Finally, while selective logging marginally enhanced tree diversity, CAD reduced native shrub diversity.Our study demonstrates that selective logging followed by CAD arrest forest recovery, as evident from the suppression of mature forest elements, loss of shrub biomass, reduced regeneration rate, and facilitation of invasive species. To abate these impacts, alternative livelihood/subsistence options that sustain forests and local communities should be explored. Additionally, CAD management should be site-specific as local ecological contexts modify their impacts on forests.

The importance of disturbance and forest structure to bird abundance in the Black Hills

The Condor ◽  
2019 ◽  
Vol 121 (1) ◽  
Author(s):  
Elizabeth A Matseur ◽  
Joshua J Millspaugh ◽  
Frank R Thompson ◽  
Brian E Dickerson ◽  
Mark A Rumble
Keyword(s):  
Forest Structure ◽  
Vegetation Type ◽  
Positive Association ◽  
Black Hills ◽  
Ground Vegetation ◽  
Percent Cover ◽  
Bird Abundance ◽  
Vegetation Characteristics ◽  
Percent Area ◽  
Landscape Level

Abstract Many North American birds associated with forest disturbances such as wildfire and mountain pine beetle (Dendroctonus ponderosae) outbreaks are declining in abundance. More information on relationships between avian abundance and forest structure and disturbance is needed to guide conservation and management. Our objective was to determine densities of American Three-toed Woodpecker (Picoides dorsalis), Black-backed Woodpecker (Picoides arcticus), Red-breasted Nuthatch (Sitta canadensis), Brown Creeper (Certhia americana), and White-winged Junco (Junco hyemalis aikeni) in relation to vegetation characteristics and disturbance at the point and landscape level in the Black Hills and Bear Lodge Mountains of South Dakota and Wyoming. We conducted 3 point counts from late March to late June 2015 and 2016 at more than 2,300 locations distributed across a gradient of forest structure and disturbance types. We estimated densities using 3-level hierarchical time-removal models that simultaneously estimated abundance, availability, and detection probability. Black-backed Woodpeckers were positively related to percent area in 1- to 3-year-old wildfires and Brown Creepers were positively associated with percent area in 4- to 5-year-old wildfires; however, Red-breasted Nuthatches were negatively related to percent area in 3- to 5-year-old wildfires. With the exception of American Three-toed Woodpeckers, species were positively related to percent cover of beetle-killed trees. Brown Creepers, White-winged Juncos, and Red-breasted Nuthatches had mixed responses to percent overstory canopy cover. White-winged Juncos also had a positive association with percent ground vegetation at the point and landscape level. Brown Creepers were strongly linked with spruce vegetation type. American Three-toed Woodpeckers, which are thought to occupy spruce forest in the Black Hills, did not show a strong relationship with any covariates. Maintaining some areas of natural disturbances along with heterogeneity of vegetation characteristics within stands and at the landscape scale will benefit the needs of a diverse bird community in the Black Hills.

La structure forestière du mont Babor

1984 ◽  
Vol 50 ◽  
Author(s):  
K. De Smet ◽  
F. Bouanza
Keyword(s):  
Forest Structure ◽  
Forest Dynamics ◽  
Forest Types ◽  
Vertical Projection ◽  
Quercus Faginea ◽  
Cedrus Atlantica ◽  
Main Species ◽  
Fundamental Research ◽  
Near Future ◽  
North Algeria

The  Babor forest is situated in the central part of north Algeria. It is  dominated by two conifers, namely Cedrus atlantica and the endemic fir Abies numidica, as well as one decidious oak  Quercus faginea. The percentage of conifers  increases on higher altitude while around the top (~ 2000 m) the oak totally  disappears. Between 1650 and 1950 m a mixture of the above-mentioned species  occurs; although they may grow in equal proportions, oak and fir are more  widespread. The distribution of the different forest types is shown on a map  and the applied classification is compared with two other types of  classifications, mentioned in the literature.           The forest structure of the oak-fir-cedar type has been illustrated by two  drawings, each with the horizontal and vertical projection of a transect. The  behaviour of each of the six main species has been analysed in terms of their  role in forest dynamics. Some propositions were made for the procedure of the  fundamental research to be done in the near future.

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