scholarly journals Forest structure along a 600 km transect of natural disturbances and seasonality gradients in central-southern Amazonia

2016 ◽  
Vol 104 (5) ◽  
pp. 1335-1346 ◽  
Author(s):  
Juliana Schietti ◽  
Demétrius Martins ◽  
Thaise Emilio ◽  
Priscila F. Souza ◽  
Carolina Levis ◽  
...  
Keyword(s):  
Forest Structure ◽  
Natural Disturbances ◽  
Southern Amazonia

Historical natural disturbances shape spruce primary forest structure and indirectly influence bird assemblage composition

2021 ◽  
Vol 481 ◽  
pp. 118647
Author(s):  
Ondrej Kameniar ◽  
Michal Baláž ◽  
Marek Svitok ◽  
Jiří Reif ◽  
Martin Mikoláš ◽  
...  
Keyword(s):  
Forest Structure ◽  
Primary Forest ◽  
Natural Disturbances ◽  
Assemblage Composition ◽  
Bird Assemblage

scholarly journals Active Restoration Initiates High Quality Forest Succession in a Deforested Landscape in Amazonia

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1022
Author(s):  
Daniel Luis Mascia Vieira ◽  
Silvia Barbosa Rodrigues ◽  
Catarina Conte Jakovac ◽  
Gustavo Paiva Evangelista da Rocha ◽  
Fagno Reis ◽  
...  
Keyword(s):  
Forest Structure ◽  
Natural Regeneration ◽  
Dominant Species ◽  
Forest Succession ◽  
Forest Recovery ◽  
Exotic Grasses ◽  
Active Restoration ◽  
Large Trees ◽  
Pioneer Trees ◽  
Southern Amazonia

Amazonia is well known for its high natural regeneration capacity; for this reason, passive restoration is normally recommended for the recovery of its degraded forests. However, highly deforested landscapes in southern Amazonia require active restoration. Since restoration methods can shape the quality and speed of early forest recovery, this study aimed to verify how active restoration pushes sites stably covered with exotic grasses towards forest recovery. We evaluated early forest succession at active restoration sites, i.e., soil plowing, direct seeding of pioneer species, and seedling stock planting at low density. We analyzed forest structure, diversity, and species composition in two age classes, 0.5–3.5 and 4.5–7.5 years old. As reference, we evaluated sites able to naturally regenerate in the same region. We sampled 36 active restoration and 31 natural regeneration sites along the Madeira River, southern Amazonia. Active restoration triggered succession to similar or higher levels of forest structure than sites where natural regeneration was taking place. The most dominant species did not overlap between active restoration and natural regeneration sites. The overall composition of species was different between the two restoration methods. Dominant species and size class distribution show that active restoration is performing successfully. Soil preparation combined with a high availability of seeds of pioneer trees resulted in a high stem density and basal area of facilitative pioneer trees. Planted seedlings added species diversity and increased density of large trees. Interventions to increase the odds of natural regeneration can be effective for non-regenerating sites in resilient landscapes.

Seventy-seven years of natural disturbances in a mountain forest area — the influence of storm, snow, and insect damage analysed with a long-term time series

2008 ◽  
Vol 38 (8) ◽  
pp. 2249-2261 ◽  
Author(s):  
Marc Hanewinkel ◽  
Johannes Breidenbach ◽  
Till Neeff ◽  
Edgar Kublin
Keyword(s):  
Time Series ◽  
Forest Structure ◽  
Forest Damage ◽  
Mountain Forest ◽  
Natural Disturbances ◽  
Storm Events ◽  
Insect Outbreaks ◽  
Planted Forests ◽  
Risk Processes

We investigated the effects of site properties, forest structure, and time on snow breakage, insect outbreaks, windthrow, and total damage for predominantly planted forests. A time series of forest damage in southwestern Germany spanning 77 years, from 1925 to 2001, was available along with a database on site properties and forest structure. The statistical modeling procedure successively addressed (i) probability of damage occurrence, (ii) timber loss in damaging events, and (iii) interaction among damage agents over time. Logistic and linear regressions were combined with multivariate autoregressive techniques. Natural disturbances were responsible for a total timber loss of 3.0 m3· ha–1· year–1. The distribution of the timber loss values over the years and over sites and stands with different properties was modeled with a standard error of 6.7 m3· ha–1· year–1. Disturbances are more likely to occur in previously damaged stands. Storm events typically provoke subsequent insect outbreaks between 2 and 6 years later. Large windthrow and snow breakage events tend to occur periodically, once every 10th, 11th, or 15th year. Analysis of disturbances as a time series significantly enhances understanding of forest risk processes.

Biomass, harvestable area, and forest structure estimated from commercial timber inventories and remotely sensed imagery in southern Amazonia

2006 ◽  
Vol 233 (1) ◽  
pp. 121-132 ◽  
Author(s):  
Ted R. Feldpausch ◽  
Andrew J. McDonald ◽  
Carlos A.M. Passos ◽  
Johannes Lehmann ◽  
Susan J. Riha
Keyword(s):  
Forest Structure ◽  
Remotely Sensed ◽  
Remotely Sensed Imagery ◽  
Southern Amazonia

Habitat associations of woodcreeper (Aves: Dendrocolaptidae) assemblage in selectively logged areas of Southern Amazonia

2015 ◽  
Vol 32 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Domingos J. Rodrigues ◽  
Fernando P. Florêncio ◽  
Jocieli Oliveira ◽  
Dalci M. M. Oliveira ◽  
Gregory W. Lollback ◽  
...  
Keyword(s):  
Forest Structure ◽  
Negative Relationship ◽  
Bird Species ◽  
Forest Degradation ◽  
Habitat Associations ◽  
Selective Logging ◽  
Habitat Specialization ◽  
Canopy Openness ◽  
Southern Amazonia

Abstract:The Brazilian Amazon rain forest has lost c. 17% of its originally forested portion, due to deforestation and selective logging. Forest degradation caused by logging contributes to loss of animal species that require specialized habitats to survive, such as woodcreepers that inhabit understorey areas. Habitat associations of woodcreeper species can be important for identifying species that have restricted distribution and/or habitat specialization. Our study investigates the effects of spatial variation in forest structure and some landscape features (canopy openness, altitude, distance to stream and exploited basal area) on the abundance and composition of woodcreeper assemblage in selectively logged tropical forests in Southern Amazonia. We used mist-nets and points count to quantify the composition and abundance of woodcreepers in 32 plots in three sites. Plots were spatially arranged in PPBio LTER sites (long-term ecological research plots, systematically spaced at 1-km intervals) in Southern Amazonia. A total of 240 individuals (captured, observed and/or heard) belonging to 11 woodcreeper species were detected. Mantel tests showed that there is no spatial autocorrelation among woodcreeper assemblage and distance between plots. Altitude and canopy openness were significantly associated with the composition of the woodcreeper assemblage. Altitude was negatively associated with species richness, and the abundance of the two dominant species (Glyphorynchus spirurus and Xiphorhynchus elegans). The negative relationship with canopy openness suggests that woodcreeper assemblages that inhabit understorey are likely to be indirectly affected by selective logging which reduces canopy cover. The selective logging indirectly changes bird species assemblages, and depending on the intensity, may result in the local extinction of some insectivorous species. Short- and long-term studies addressing different intensities of selective logging are needed to determine the impacts on the bird species and forest structure.

scholarly journals Active Restoration Initiates High Quality Forest Succession In A Deforested Landscape In Amazonia

2021 ◽  
Author(s):  
Daniel Luis Mascia Vieira ◽  
Silvia Rodrigues ◽  
Catarina Conte Jakovac ◽  
Gustavo Paiva Evangelista da Rocha ◽  
Fagno Reis ◽  
...  
Keyword(s):  
Forest Structure ◽  
Natural Regeneration ◽  
Dominant Species ◽  
Forest Succession ◽  
Forest Recovery ◽  
Stem Density ◽  
Active Restoration ◽  
Large Trees ◽  
Pioneer Trees ◽  
Southern Amazonia

Abstract Background: Amazonia is well known for its high natural regeneration capacity; for this reason, passive restoration is normally recommended for the recovery of its degraded forests. However, highly deforested landscapes in southern Amazonia require active restoration. Since restoration methods can shape the quality and speed of early forest recovery, this study aimed to verify how active restoration pushes non-resilient sites towards forest recovery. Methods: We evaluated early forest succession at active restoration sites, i.e. soil plowing, direct seeding of pioneer species and seedling stock planting at low density. We analyzed forest structure, diversity and species composition in two age classes, 0.5 – 3.5 and 4.5 – 7.5 years old. As reference, we evaluated natural regeneration as performed on more resilient sites in the same region. We sampled 36 active restoration and 31 natural regeneration sites along the Madeira river, southern Amazonia. Results: Active restoration triggered succession to similar or higher levels of forest structure than sites where natural regeneration was taking place. The most dominant species did not overlap between active restoration and natural regeneration sites. The overall composition of species was different between the two restoration methods. Dominant species and size class distribution indicate that active restoration is performing successfully. Conclusions: Soil preparation combined with a high availability of seeds of pioneer trees resulted in a high stem density and basal area of facilitative pioneer trees. Planted seedlings added species diversity and increased density of large trees. Interventions to increase the odds of natural regeneration can be effective for non-resilient sites located in resilient landscapes.

Habitat fragmentation causes collapse of kelp recruitment

2020 ◽  
Vol 648 ◽  
pp. 111-123
Author(s):  
C Layton ◽  
MJ Cameron ◽  
M Tatsumi ◽  
V Shelamoff ◽  
JT Wright ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Patch Size ◽  
Life Stage ◽  
Extended Period ◽  
Anthropogenic Disturbances ◽  
Anthropogenic Sources ◽  
Kelp Forests ◽  
Natural Disturbances ◽  
Short Term ◽  
Turf Algae

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches <1 m2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.

Evaluation of roe deer effects upon forest structure in Nogueira Mountain (NE of Portugal)

2007 ◽  
Vol 3 (2) ◽  
Author(s):  
Aurora Monzon ◽  
António L. Crespí ◽  
Sónia Pinto ◽  
Adriano Castro ◽  
Claúdia P. Fernandes ◽  
...  
Keyword(s):  
Forest Structure ◽  
Roe Deer
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