Environmental heterogeneity and biotic interactions mediate climate impacts on tropical forest regeneration

Abstract Key message: The Enrichment Plantation of Akure Forest Reserve is one of the forests currently experiencing a 17-year-long post-disturbance following deforestation and fragmentation in Nigeria. Context: To better understand the contribution of enrichment planting on forest regeneration and restoration, when the Enrichment Plantation after 17 years of post-disturbance was examined. Aims: We studied the recruitment drive of aboveground and undergrowth stands of an Enrichment Plantation in the tropical forest reserve. We assess the trees diversity, species compositions, species richness, and growth forms of the vegetations. Methods: A total of 3(50m x50m) plots were sampled. A total of 47 aboveground tree species and 45 undergrowth stands from Enrichment Plantation were identified. A statistical analysis were used to quantified the data obtained from this resultsResults: The result shows an increase in the diversity and an even distribution of the species of the aboveground forest trees, compared to the undergrowth stands. Conversely, the aboveground forest trees have lower species richness as compared to the level of undergrowth stands. The sapling density was significantly higher than the aboveground tree of the. It was also observed that the aboveground forest trees and undergrowth stands are somewhat similar in species compositions, which implies that sapling recruitment is a key determinant of the tree species composition of the forest.Conclusion: It is then concluded that the method adopted for restoration encouraged species diversity in this successional forest among the aboveground trees species and undergrowth.

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The proportion of core species in a community varies with spatial scale and environmental heterogeneity

10.7287/peerj.preprints.27158v1 ◽

2018 ◽

Author(s):

Molly F Jenkins ◽

Ethan P White ◽

Allen H Hurlbert

Keyword(s):

Spatial Scale ◽

Environmental Heterogeneity ◽

Biotic Interactions ◽

Bird Community ◽

Species Variation ◽

Ecological Communities ◽

Transient Species ◽

Ecological Processes ◽

Core Species ◽

Wide Range

Ecological communities are composed of a combination of core species that maintain local viable populations and transient species that occur infrequently due to dispersal from surrounding regions. Preliminary work indicates that while core and transient species are both commonly observed in community surveys of a wide range of taxonomic groups, their relative prevalence varies substantially from one community to another depending upon the spatial scale at which the community was characterized and its environmental context. We used a geographically extensive dataset of 968 bird community time series to quantitatively describe how the proportion of core species in a community varies with spatial scale and environmental heterogeneity. We found that the proportion of core species in an assemblage increased with spatial scale in a positive decelerating fashion with a concomitant decrease in the proportion of transient species. Variation in the shape of this scaling relationship between sites was related to regional environmental heterogeneity, with lower proportions of core species at a given scale associated with high environmental heterogeneity. This influence of scale and environmental heterogeneity on the proportion of core species may help resolve discrepancies between studies of biotic interactions, resource availability, and mass effects conducted at different scales, because the importance of these and other ecological processes are expected to differ substantially between core and transient species.

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Biotic interactions affect fitness across latitudes, but only drive local adaptation in the tropics

10.1101/575498 ◽

2019 ◽

Cited By ~ 1

Author(s):

Anna L. Hargreaves ◽

Rachel M. Germain ◽

Megan Bontrager ◽

Joshua Persi ◽

Amy L. Angert

Keyword(s):

Local Adaptation ◽

Environmental Heterogeneity ◽

Meta Analysis ◽

Biotic Interactions ◽

Common Garden ◽

Spatiotemporal Scales ◽

Common Garden Experiments ◽

Experimental Treatments ◽

The Tropics ◽

Biotic Environment

AbstractLocal adaptation to broad-scale environmental heterogeneity can increase species’ distributions and diversification, but which environmental components commonly drive local adaptation— particularly the importance of biotic interactions—is unclear. Biotic interactions should drive local adaptation when they impose consistent divergent selection; if this is common we expect experiments to detect more frequent and stronger local adaptation when biotic interactions are left intact. We tested this hypothesis using a meta-analysis of common-garden experiments from 138 studies (149 taxa). Across studies, local adaptation was common and biotic interactions affected fitness. Nevertheless, local adaptation was neither more common nor stronger when biotic interactions were left intact, either between experimental treatments within studies (control vs. biotic interactions experimentally manipulated) or between studies that used natural vs. biotically-altered transplant environments. However, tropical studies, which comprised only 7% of our data, found strong local adaptation in intact environments but not when negative biotic interactions were ameliorated, suggesting that interactions frequently drive local adaptation in the tropics. Our results suggest that biotic interactions often fail to drive local adaptation even though they affect fitness, perhaps because the temperate-zone biotic environment is less predictable at the spatiotemporal scales required for local adaptation.

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