EFFECT OF TREE IDENTITY, TEMPORAL VARIATION AND EDAPHIC PARAMETERS ON THE STRUCTURE OF THE EDAPHIC COMMUNITY OF ORIBATID MITES IN AN EVERGREEN TROPICAL FOREST OF MEXICO

Understanding the structure and dynamics of highly diverse tropical forests is challenging. Here we investigate the factors that drive the spatio-temporal variation of local tree numbers and species richness in a tropical forest (including 1250 plots of 20 × 20 m 2 ). To this end, we use a series of dynamic models that are built around the local spatial variation of mortality and recruitment rates, and ask which combination of processes can explain the observed spatial and temporal variation in tree and species numbers. We find that processes not included in classical neutral theory are needed to explain these fundamental patterns of the observed local forest dynamics. We identified a large spatio-temporal variability in the local number of recruits as the main missing mechanism, whereas variability of mortality rates contributed to a lesser extent. We also found that local tree numbers stabilize at typical values which can be explained by a simple analytical model. Our study emphasized the importance of spatio-temporal variability in recruitment beyond demographic stochasticity for explaining the local heterogeneity of tropical forests.

Download Full-text

Diversity of Pseudoscorpiones (Arthropoda: Arachnida) in two fragments of dry tropical forest in the colombian Caribbean region

Caldasia ◽

10.15446/caldasia.v41n1.72189 ◽

2019 ◽

Vol 41 (1) ◽

pp. 139-151

Author(s):

Eduardo Villarreal ◽

Neis Martínez ◽

Catalina Romero-Ortiz

Keyword(s):

Tropical Forest ◽

Temporal Variation ◽

Rainy Season ◽

Dry Season ◽

Caribbean Region ◽

Limited Information ◽

Dry Tropical Forest ◽

The Caribbean ◽

Spatio Temporal ◽

Collection Methods

The Dry Tropical Forest (DTF) is one of the most diverse yet threatened biomes of Colombia. There is limited information about the richness of the order Pseudoscorpiones (Arachnida) in this ecosystem in the country. Pseudoscorpions are ecologically interesting, as they may be good indicators of habitat conservation. However, it is still necessary to gather more knowledge related to its spatio-temporal variation. In this study, pseudoscorpion diversity variation was assessed in two fragments of the Dry Tropical Forest in the Caribbean region of Colombian: Reserva Campesina La Montaña (RCM) and Reserva La Flecha (RLF). Four samplings were carried out between March and September of 2016 to include the dry and rainy season. Pseudoscorpions were collected using litter sifting (SL) and manual capture (MC). A total of 260 individuals belonging to five families and eight species were collected. The most abundant was Pachyolpium granulatum (Olpiidae) and the richest family was Chernetidae. The collection methods were effective and complementary. Spatial variation was significant, but no temporal variation was observed however, there was a marked difference between the abundance at RCM in the dry season and the rainy season. In contrast, at RLF most individuals were found in the dry season in comparison with the rainy season. These new faunistic data is the first of its order in the Atlántico and Bolívar department.

Download Full-text

Effects of environmental heterogeneity and temporal variation on ecological relationships of vegetation in a seasonally dry tropical forest in Brazil

TURKISH JOURNAL OF BOTANY ◽

10.3906/bot-1904-12 ◽

2020 ◽

Vol 44 (3) ◽

pp. 232-244

Author(s):

Alisson Borges Miranda SANTOS ◽

Nathalle Cristine Alencar FAGUNDES ◽

Cléber Rodrigo de SOUZA ◽

Vinicius Andrade MAIA ◽

Wilder Bento da SILVA ◽

...

Keyword(s):

Tropical Forest ◽

Temporal Variation ◽

Environmental Heterogeneity ◽

Seasonally Dry Tropical Forest ◽

Dry Tropical Forest ◽

Seasonally Dry ◽

Ecological Relationships

Download Full-text

Strong temporal variation in treefall and branchfall rates in a tropical forest is related to extreme rainfall: results from 5 years of monthly drone data for a 50 ha plot

Biogeosciences ◽

10.5194/bg-18-6517-2021 ◽

2021 ◽

Vol 18 (24) ◽

pp. 6517-6531

Author(s):

Raquel Fernandes Araujo ◽

Samuel Grubinger ◽

Carlos Henrique Souza Celes ◽

Robinson I. Negrón-Juárez ◽

Milton Garcia ◽

...

Keyword(s):

Tropical Forest ◽

Temporal Variation ◽

Forest Canopy ◽

Tree Mortality ◽

Extreme Rainfall ◽

Barro Colorado Island ◽

Weibull Function ◽

Wet Season ◽

Wind Speeds ◽

Canopy Disturbance

Abstract. A mechanistic understanding of how tropical-tree mortality responds to climate variation is urgently needed to predict how tropical-forest carbon pools will respond to anthropogenic global change, which is altering the frequency and intensity of storms, droughts, and other climate extremes in tropical forests. We used 5 years of approximately monthly drone-acquired RGB (red–green–blue) imagery for 50 ha of mature tropical forest on Barro Colorado Island, Panama, to quantify spatial structure; temporal variation; and climate correlates of canopy disturbances, i.e., sudden and major drops in canopy height due to treefalls, branchfalls, or the collapse of standing dead trees. Canopy disturbance rates varied strongly over time and were higher in the wet season, even though wind speeds were lower in the wet season. The strongest correlate of monthly variation in canopy disturbance rates was the frequency of extreme rainfall events. The size distribution of canopy disturbances was best fit by a Weibull function and was close to a power function for sizes above 25 m2. Treefalls accounted for 74 % of the total area and 52 % of the total number of canopy disturbances in treefalls and branchfalls combined. We hypothesize that extremely high rainfall is a good predictor because it is an indicator of storms having high wind speeds, as well as saturated soils that increase uprooting risk. These results demonstrate the utility of repeat drone-acquired data for quantifying forest canopy disturbance rates at fine temporal and spatial resolutions over large areas, thereby enabling robust tests of how temporal variation in disturbance relates to climate drivers. Further insights could be gained by integrating these canopy observations with high-frequency measurements of wind speed and soil moisture in mechanistic models to better evaluate proximate drivers and with focal tree observations to quantify the links to tree mortality and woody turnover.

Download Full-text

Tree identity surpasses tree diversity in affecting the community structure of oribatid mites (Oribatida) of deciduous temperate forests

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2013.03.024 ◽

2013 ◽

Vol 63 ◽

pp. 154-162 ◽

Cited By ~ 21

Author(s):

Verena Eissfeller ◽

Christina Langenbruch ◽

Andreas Jacob ◽

Mark Maraun ◽

Stefan Scheu

Keyword(s):

Community Structure ◽

Temperate Forests ◽

Tree Diversity ◽

Oribatid Mites ◽

Tree Identity

Download Full-text

Strong temporal variation in treefall and branchfall rates in a tropical forest is explained by rainfall: results from five years of monthly drone data for a 50-ha plot

10.5194/bg-2021-102 ◽

2021 ◽

Author(s):

Raquel Fernandes Araujo ◽

Samuel Grubinger ◽

Carlos Henrique Souza Celes ◽

Robinson I. Negrón-Juárez ◽

Milton Garcia ◽

...

Keyword(s):

Tropical Forest ◽

Temporal Variation ◽

Forest Canopy ◽

Barro Colorado Island ◽

Weibull Function ◽

Wet Season ◽

Canopy Disturbance ◽

Dead Trees ◽

Standing Dead ◽

Standing Dead Trees

Abstract. A mechanistic understanding of how tropical tree mortality responds to climate variation is urgently needed to predict how tropical forest carbon pools will respond to anthropogenic global change, which is altering the frequency and intensity of storms, droughts, and other climate extremes in tropical forests. We used five years of approximately monthly drone-acquired RGB imagery for 50 ha of mature tropical forest on Barro Colorado Island, Panama, to quantify spatial structure, temporal variation, and climate correlates of canopy disturbances, i.e., sudden and major drops in canopy height due to treefalls, branchfalls, or collapse of standing dead trees. Treefalls accounted for 77 % of the total area and 60 % of the total number of canopy disturbances in treefalls and branchfalls combined. The size distribution of canopy disturbances was close to a power function for sizes above 25 m2, and best fit by a Weibull function overall. Canopy disturbance rates varied strongly over time and were higher in the wet season, even though windspeeds were lower in the wet season. The strongest correlate of temporal variation in canopy disturbance rates was the frequency of 1-hour rainfall events above the 99.4th percentile (here 35.7 mm hour−1, r = 0.67). We hypothesize that extreme high rainfall is associated with both saturated soils, increasing risk of uprooting, and with gusts having high horizontal and vertical windspeeds that increase stresses on tree crowns. These results demonstrate the utility of repeat drone-acquired data for quantifying forest canopy disturbance rates over large spatial scales at fine temporal and spatial resolution, thereby enabling strong tests of linkages to drivers. Future studies should include high frequency measurements of vertical and horizontal windspeeds and soil moisture to better capture proximate drivers, and incorporate additional image analyses to quantify standing dead trees in addition to treefalls.

Download Full-text