Succession and seasonality of a Brazilian secondary tropical dry forest: Phenology and climate moderation

• Published in: Forest ecology and management 2024-09, Vol.568, p.122151, Article 122151
• Main Authors: Rankine, Cassidy, Sanchez-Azofeifa, Arturo, do Espirito-Santo, Mario Marcos, Stan, Kayla
• Format: Article
• Language: English
• Subjects: Climate Moderation; Micrometeorology; Phenology; Secondary Succession; Tropical Dry Forests; Wireless Sensor Networks
• ISSN: 0378-1127
• DOI: 10.1016/j.foreco.2024.122151

With large tracts of Tropical Dry Forests (TDF) in the Americas previously deforested, many places are currently undergoing secondary ecological succession. These processes vary in time and space, creating a landscape with forests of different ages or successional stages. These secondary forests need moreneed more understanding about how their ecosystem functionality is restored and recovering along the succession path. In particular, it is poorly understood how different successional stages moderate extremes of Essential Climatic Variables (ECV) such as temperature, relative humidity, soil moisture, and the fraction of Absorbed Photosynthetic Active Radiation (fAPAR). This paper, therefore, studies the linkages between high temporal resolution tower-based optical canopy phenology time series and seasonal changes in local ECV conditions between early (10–12 years) and late (50+ years) successional stage TDF in southeastern Brazil. We compare diurnal and seasonal patterns of understory ECVs between early/late plots and investigate the canopy’s Climate Moderating Capacity (CMC). Our data indicate at least 100 mm of precipitation within two weeks is necessary to initiate leaf flushing in this TDF. We also find that soil moisture and daytime air humidity strongly correlate (R2 > 0.75) with seasonal patterns in canopy vegetation greenness indices and fAPAR with a cross-correlation time lag peak of 12–15 days. Our results suggest that the late stage is more effective at cooling (−1.4 ± 0.6 °C vs −0.8 ± 0.6 °C) and reducing daytime evaporation (−0.41 ± 0.2 kPa vs −0.18 ± 0.12 °C) in the understory during the growing season than the early stage. Results suggest that the CMC varies with seasonal canopy leaf area dynamics and with heat and moisture scales, becoming significantly stronger when temperatures and vapour pressure deficits were highest, and correlated strongly with canopy fAPAR dynamics (R2 = 0.82). These findings demonstrate that TDFs can effectively regain microclimatic buffering capacity. •The study focuses on how early and late successional stages of TDFs restore ecosystem functionality.•Late succession TDFs are more efficient in cooling and reducing daytime evapotranspiration than early succession TDFs.•There is a strong correlation between canopy vegetation greenness indices and seasonal ECVs patterns.•The microclimatic buffering capacity of TDFs is a complex interplay of seasonal leaf area dynamics and climatic conditions.