What drives clearing of old-growth forest over secondary forests in tropical shifting cultivation systems? Evidence from the Peruvian Amazon

2021 ◽  
Vol 189 ◽  
pp. 107170
Author(s):  
Oliver T. Coomes ◽  
Yuanyu Cheng ◽  
Yoshito Takasaki ◽  
Christian Abizaid
Keyword(s):  
Shifting Cultivation ◽  
Secondary Forests ◽  
Peruvian Amazon ◽  
Old Growth ◽  
Cultivation Systems ◽  
Old Growth Forest

scholarly journals Smallholder agriculture results in stable forest cover in riverine Amazonia

2021 ◽  
Author(s):  
Oliver T. Coomes ◽  
Margaret Kalacska ◽  
Yoshito Takasaki ◽  
Christian Abizaid ◽  
Tristan Grupp
Keyword(s):  
Satellite Imagery ◽  
Shifting Cultivation ◽  
Forest Cover ◽  
Secondary Forest ◽  
Forest Disturbance ◽  
Secondary Forests ◽  
Smallholder Agriculture ◽  
Peruvian Amazon ◽  
Terra Firme ◽  
Old Growth

Abstract Recent studies point to a rapid increase in small-scale deforestation in Amazonia. Where people live along the rivers of the basin, customary shifting cultivation creates a zone of secondary forest, orchards and crop fields around communities in what was once was old-growth terra firme forest. Visible from satellite imagery as a narrow but extensive band of forest disturbance along rivers, this zone is often considered as having been deforested. In this paper we assess forest disturbance and the dynamics of secondary forests around 275 communities along a 725 km transect on the Napo and Amazon rivers in the Peruvian Amazon. We used high-resolution satellite imagery to define the ‘working area’ around each community, based on the spatial distribution of forest/field patches and the visible boundary between old-growth and secondary forests. Land cover change was assessed between ca. 1989 and 2015 using CLASliteTM image classification. Statistical analyses using community and household-level data from the Peruvian Amazon Rural Livelihoods and Poverty (PARLAP) Project identified the predictors of the extent of forest disturbance and the dynamics of secondary forests around communities. Although shifting cultivation is the primary driver of old-growth forest loss, we find that secondary forest cover which replaces old-growth forests is stable through time, and that both the area and rate of expansion into old-growth forests are modest when compared to forest conversion in Peru for colonization and plantation development. Our findings challenge the notion that smallholder agriculture along rivers is an important threat to terra firme forests in Amazonia and point to the importance of protecting forests on community lands from loggers, colonists and other outsiders.

Long-term performance and herbivory of tree seedlings planted into primary and secondary forests of Central Amazonia

2013 ◽  
Vol 29 (4) ◽  
pp. 301-311 ◽  
Author(s):  
Julieta Benítez-Malvido ◽  
Miguel Martínez-Ramos
Keyword(s):  
Secondary Forest ◽  
Tree Seedlings ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Central Amazonia ◽  
One Year ◽  
Term Performance ◽  
Over Time

Abstract:Plant survival and growth in tropical rain forest are affected by different biotic and abiotic forces. As time elapses and plants grow the relative importance of such forces as regeneration inhibitors and/or facilitators may change according to habitat and species. To detect within- and among-species divergences in performance over time in different habitats we followed, for nearly a decade, the survival, growth and herbivory of seedlings of the native tree species: Chrysophyllum pomiferum, Micropholis venulosa and Pouteria caimito. In Central Amazonia, young seedlings were planted into old-growth and secondary forests dominated by Vismia spp. One year after planting, C. pomiferum ranked first (i.e. fast growth, fewer dead and less herbivory) for both habitats, followed by M. venulosa and P. caimito. Initial trends changed over time. In the long term, M. venulosa ranked first for both habitats, followed by C. pomiferum and P. caimito ranked consistently lowest. Within-species divergences in growth and herbivory were greater in secondary forest. Initial seedling responses cannot always be used to predict species persistence in the long term. Contrary to previous estimations, old-growth-forest species can persist under Vismia spp. stands, at least when planted.

scholarly journals Recovery of Functional Diversity Following Shifting Cultivation in Tropical Monsoon Forests

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 506 ◽  
Author(s):  
Fuying Deng ◽  
Yunling He ◽  
Runguo Zang
Keyword(s):  
Functional Diversity ◽  
Functional Traits ◽  
Shifting Cultivation ◽  
Forest Ecosystems ◽  
Recovery Process ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forests ◽  
Tropical Monsoon ◽  
Monsoon Forests

The relationship between biodiversity and ecosystem functioning is an important issue in ecology. Plant functional traits and their diversity are key determinants of ecosystem function in changing environments. Understanding the successional dynamics of functional features in forest ecosystems is a first step to their sustainable management. In this study, we tested the changes in functional community composition with succession in tropical monsoon forests in Xishuangbanna, China. We sampled 33 plots at three successional stages—~40-year-old secondary forests, ~60-year-old secondary forests, and old growth forests—following the abandonment of the shifting cultivation land. Community-level functional traits were calculated based on measurements of nine functional traits for 135 woody plant species. The results show that the community structures and species composition of the old-growth forests were significantly different to those of the secondary stands. The species diversity, including species richness (S), the Shannon–Weaver index (H), and Pielou’s evenness (J), significantly increased during the recovery process after shifting cultivation. The seven studied leaf functional traits (deciduousness, specific leaf area, leaf dry matter content, leaf nitrogen content, leaf phosphorus content, leaf potassium content and leaf carbon content) changed from conservative to acquisitive syndromes during the recovery process, whereas wood density showed the opposite pattern, and seed mass showed no significant change, suggesting that leaf traits are more sensitive to environmental changes than wood or seed traits. The functional richness increased during the recovery process, whereas the functional evenness and divergence had the highest values in the 60-year-old secondary communities. Soil nutrients significantly influenced functional traits, but their effects on functional diversity were less obvious during the secondary succession after shifting cultivation. Our study indicates that the recovery of tropical monsoon forests is rather slow; secondary stands recover far less than the old growth stands in terms of community structure and species and functional diversity, even after about half a century of recovery, highlighting the importance of the conservation of old growth tropical monsoon forest ecosystems.

scholarly journals Biodiversity recovery of Neotropical secondary forests

2019 ◽  
Vol 5 (3) ◽  
pp. eaau3114 ◽  
Author(s):  
Danaë M. A. Rozendaal ◽  
Frans Bongers ◽  
T. Mitchell Aide ◽  
Esteban Alvarez-Dávila ◽  
Nataly Ascarrunz ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Tree Species ◽  
Anthropogenic Disturbance ◽  
Secondary Forests ◽  
Old Growth ◽  
Rarefaction Analysis ◽  
Old Growth Forest ◽  
Dual Strategy ◽  
Tropical Landscapes

Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.

Decoupled responses of native and exotic tree diversities to distance from old‐growth forest and soil phosphorus in novel secondary forests

2020 ◽  
Author(s):  
Hao Ran Lai ◽  
Germaine Su Yin Tan ◽  
Louise Neo ◽  
Carmen Yingxin Kee ◽  
Alex Thiam Koon Yee ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Exotic Tree

scholarly journals Second-growth and small forest clearings have little effect on the temporal activity patterns of Amazonian phyllostomid bats

2019 ◽  
Vol 66 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Ricardo Rocha ◽  
Adrià López-Baucells ◽  
Fábio Z Farneda ◽  
Diogo F Ferreira ◽  
Inês Silva ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Behavioral Responses ◽  
Species Level ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Second Growth ◽  
Tropical Landscapes ◽  
Small Forest ◽  
Temporal Overlap

Abstract Secondary forests and human-made forest gaps are conspicuous features of tropical landscapes. Yet, behavioral responses to these aspects of anthropogenically modified forests remain poorly investigated. Here, we analyze the effects of small human-made clearings and secondary forests on tropical bats by examining the guild- and species-level activity patterns of phyllostomids sampled in the Central Amazon, Brazil. Specifically, we contrast the temporal activity patterns and degree of temporal overlap of 6 frugivorous and 4 gleaning animalivorous species in old-growth forest and second-growth forest and of 4 frugivores in old-growth forest and forest clearings. The activity patterns of frugivores and gleaning animalivores did not change between old-growth forest and second-growth, nor did the activity patterns of frugivores between old-growth forest and clearings. However, at the species level, we detected significant differences for Artibeus obscurus (old-growth forest vs. second-growth) and A. concolor (old-growth forest vs. clearings). The degree of temporal overlap was greater than random in all sampled habitats. However, for frugivorous species, the degree of temporal overlap was similar between old-growth forest and second-growth; whereas for gleaning animalivores, it was lower in second-growth than in old-growth forest. On the contrary, forest clearings were characterized by increased temporal overlap between frugivores. Changes in activity patterns and temporal overlap may result from differential foraging opportunities and dissimilar predation risks. Yet, our analyses suggest that activity patterns of bats in second-growth and small forest clearings, 2 of the most prominent habitats in humanized tropical landscapes, varies little from the activity patterns in old-growth forest.

Do secondary forests act as refuges for old growth forest animals? Recovery of ant diversity in the Atlantic forest of Brazil

2008 ◽  
Vol 141 (3) ◽  
pp. 733-743 ◽  
Author(s):  
Jochen H. Bihn ◽  
Manfred Verhaagh ◽  
Martin Brändle ◽  
Roland Brandl
Keyword(s):  
Atlantic Forest ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Ant Diversity

scholarly journals Forest structural parameters and aboveground biomass in old-growth and secondary forests along an elevational gradient in Mexico

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Martina Alrutz ◽  
Jorge Antonio Gómez Díaz ◽  
Ulf Schneidewind ◽  
Thorsten Krömer ◽  
Holger Kreft
Keyword(s):  
Climate Change ◽  
Forest Structure ◽  
Aboveground Biomass ◽  
Basal Area ◽  
Elevational Gradient ◽  
Stem Density ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests

Background: Tropical montane forests are important reservoirs of carbon and biodiversity but are threatened by deforestation and climate change. It is important to understand how forest structure and aboveground biomass change along gradients of elevation and succession. Questions: What are the interactive effect of elevation and two stages of succession on forest structure parameters? Studied species: Tree communities. Study site and dates: Cofre de Perote, Veracruz, Mexico. August to December 2015. Methods: We studied four sites along an elevational gradient (500, 1,500, 2,500, and 3,500 m). At each elevation and each forest type, we established five 20 × 20 m plots (n = 40 plots). Within each plot, we measured stem density, mean diameter at breast height (dbh), and tree height and derived basal area and aboveground biomass (AGB). Results: AGB peaked at 2,500 m and was significantly related to elevation and succession, with higher values in old-growth forests than in secondary forests at higher altitudes. Lower values of mean dbh and basal area were found at higher elevations. At the lowest elevation, both successional stages had the same values of stem density and AGB. At both lower elevations, secondary forests had higher values of dbh and basal area. There were high biomass stocks in the old-growth forest at 2,500 and 3,500 m. Conclusions: Old-growth forests at higher elevations are threatened by deforestation, consequently these remaining fragments must be preserved because of their storage capacity for biomass and their ability to mitigate climate change.

scholarly journals Aboveground forest biomass varies across continents, ecological zones and successional stages: refined IPCC default values for tropical and subtropical forests

2021 ◽  
Author(s):  
Danaë M. A. Rozendaal ◽  
Daniela Requena Suarez ◽  
Veronique De Sy ◽  
Valerio Avitabile ◽  
Sarah Carter ◽  
...  
Keyword(s):  
Secondary Forests ◽  
Ecological Zone ◽  
Old Growth ◽  
Successional Stage ◽  
Subtropical Forests ◽  
Ecological Zones ◽  
Old Growth Forest ◽  
Ipcc Guidelines ◽  
Successional Stages ◽  
The Tropics

Abstract For monitoring and reporting forest carbon stocks and fluxes, many countries in the tropics and subtropics rely on default values of forest aboveground biomass (AGB) from the Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas (GHG) Inventories. Default IPCC forest AGB values originated from 2006, and are relatively crude estimates of average values per continent and ecological zone. The 2006 default values were based on limited plot data available at the time, methods for their derivation were not fully clear, and no distinction between successional stages was made. As part of the 2019 Refinement to the 2006 IPCC Guidelines for GHG Inventories, we updated the default AGB values for tropical and subtropical forests based on AGB data from >25,000 plots in natural forests and a global AGB map where no plot data were available. We calculated refined AGB default values per continent, ecological zone, and successional stage, and provided a measure of uncertainty. AGB in tropical and subtropical forests varies by an order of magnitude across continents, ecological zones, and successional stage. Our refined default values generally reflect the climatic gradients in the tropics, with more AGB in wetter areas. AGB is generally higher in old-growth than in secondary forests, and higher in older secondary (regrowth >20 years old and degraded/logged forests) than in young secondary forests (≤20 years old). While refined default values for tropical old-growth forest are largely similar to the previous 2006 default values, the new default values are 4.0 to 7.7-fold lower for young secondary forests. Thus, the refined values will strongly alter estimated carbon stocks and fluxes, and emphasize the critical importance of old-growth forest conservation. We provide a reproducible approach to facilitate future refinements and encourage targeted efforts to establish permanent plots in areas with data gaps.

Old-growth forests: Data gaps and challenges

2003 ◽  
Vol 79 (3) ◽  
pp. 645-651 ◽  
Author(s):  
Ole Hendrickson
Keyword(s):  
Ecosystem Services ◽  
Sustainable Forest Management ◽  
Ecosystem Approach ◽  
Ecosystem Change ◽  
Secondary Forests ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Considerable Impact ◽  
Growth Features

How much old growth is there? How much was there? Is remaining old growth disappearing? If so, how fast and why? Is any more old growth being created? How fragmented are old-growth forests? What other forest types and land uses surround them? Scientists see these as challenging questions, never to be fully resolved. Policy makers see information gaps and want answers. They assume that because the public values old-growth forests, their continuing availability must be assured. Forest managers need to be convinced that old-growth forests provide unique values before taking costly measures to conserve them. The relative stability of old-growth forests is interesting from a management perspective. Are old-growth forests more resistant to high-intensity disturbances, such as crown fires and violent storms? Do they resist insect outbreaks? A related issue is the quality of ecosystem services provided by old-growth forests. Do they have an exceptional ability to provide clean water, to stabilize hydrologic regimes, and to moderate local climates? Can they be used to test hypotheses about complexity, stability, resilience, and ecosystem change? These questions provide a strong rationale for developing working definitions of old-growth forests, for retaining areas of old-growth forest, and for replicating old-growth features in landscapes managed for timber production. Old-growth forests are desirable sites for monitoring, serving as benchmarks for adaptive management. Knowledge about old-growth forests has already had a considerable impact on policy and management, particularly in coastal regions. Current research and monitoring systems may not be adequate for the task of identifying and describing the biological complexity and diversity inherent in old-growth forests. New investments in collecting and managing data from old-growth (and secondary) forests are needed, and will pay manifold dividends to future generations of Canadians. This paper suggests that the central role of old-growth forests in developing sustainable forest management should create an incentive for the forest science, policy, and management communities to unite in support of their conservation. Key words: biodiversity, gene conservation, resilience, ecosystem approach, information management, ecosystem services

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