Canopy recovery four years after logging: a management study in a southern brazilian secondary forest

Janine Kervald Likoski,Daniel Augusto Da Silva,Alfredo Celso Fantini,Alexander Christian Vibrans

doi:10.1590/01047760202127012366

Janine Kervald Likoski, Daniel Augusto Da Silva + Show 2 more

Open Access

https://doi.org/10.1590/01047760202127012366

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Abstract

ABSTRACT Background: Understanding forest dynamics after logging is essential to define forest management cycles and intensities. In secondary forest, especially in the Atlantic Forest Domain, these studies are still scarce. Monitoring of the canopy structure after tree harvesting can be performed by hemispherical photographs, where canopy opening is commonly analyzed. This study evaluated changes in canopy opening four years after tree harvesting in a secondary Atlantic Rainforest in southern Brazil. We used hemispherical photographs to determine the Canopy Openness (CO), Leaf Area Index (LAI), and Diffuse Fraction of Photosynthetically Active Absorbed Radiation (FAPARdif) in eleven permanent plots. Results: We found that harvesting resulted in a momentary increase in canopy opening and light availability in the understory. Four years after harvesting, CO, LAI and FAPARdif recovered or even exceeded the original values of the forest. We observed a significant correlation between CO and number of trees harvested with DBH > 30 cm. Weak correlations were found between these canopy related variables and the logging intensity. Conclusion: In conclusion, we recognized that changes of CO, LAI and FAPARdif after timber harvesting presented short duration. This indicates that the applied logging intensities, 21.8 to 51.1% of the total basal area, did not exceed the resilience of the forest canopy and it’s recovering four years later. However, additional studies should be carried out to observe vegetation dynamics, such as species composition, vertical structure, productivity and community stability, in order to improve management schemes of secondary stands in the Atlantic Forest.

Highlights

Secondary forests are frequent or even dominant in many man-modified tropical landscapes (Gardner et al, 2009; Chazdon et al, 2009)
Harvesting caused the Canopy Openness (CO) to triple compared to 2014 values, a significant increase, but openings were reverted to values statistically similar to the values observed before harvesting
By analyzing the linear correlations between current CO, Leaf Area Index (LAI) and FAPARdif (2019) and harvesting intensity, we found a significant correlation between CO and the number of harvested trees with DBH > 30 cm (Table 2, Figure 4)

Summary

Introduction

Secondary forests are frequent or even dominant in many man-modified tropical landscapes (Gardner et al, 2009; Chazdon et al, 2009). About one third of the deforested forests in the Neotropics undergo secondary succession annually (Aide et al, 2013), and most of the global forest cover falls into naturally regenerated forests (74%) (Fao, 2016). These formations are a repository of biodiversity and are responsible for important ecosystem services (Poorter et al, 2016; Melo et al, 2013; Gilroy et al, 2014). In secondary forest, especially in the Atlantic Forest Domain, these studies are still scarce. This study evaluated changes in canopy opening four years after tree harvesting in a secondary Atlantic Rainforest in southern Brazil. We used hemispherical photographs to determine the Canopy Openness (CO), Leaf Area Index (LAI), and Diffuse Fraction of Photosynthetically Active Absorbed Radiation (FAPARdif) in eleven permanent plots

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Results

Discussion

Conclusion