Nicole Gutierrez performs chlorophyll content measurements 3 times per leaf, in addition to measuring leaf height and stem diameter.

The leaf chlorophyll content meters (CCM) determine the relative amount of leaf chlorophyll by measuring the absorbance of the leaf in two wavelengths.

Leaf samples are collected during the first hours of the day (~3:00 am) using red-light; they are cut and taken to the dark room for chlorophyll fluorescence measurements using a fluorometer (FP100).

Nicole collects the leaves and takes them to the dark room for measurements at different temperatures.

From each leaf 8 disks are taken for chlorophyll fluorescence parameters measurements at different temperatures.

Leaf disks are weight before and after drying them in the oven. This data is used for leaf mass per area calculations.

Nicole weighing the samples after all measurements have been performed and the disks have been in the oven for 2-3 days.

Nicole Gutierrez performs chlorophyll content measurements 3 times per leaf, in addition to measuring leaf height and stem diameter.

The leaf chlorophyll content meters (CCM) determine the relative amount of leaf chlorophyll by measuring the absorbance of the leaf in two wavelengths.

Leaf samples are collected during the first hours of the day (~3:00 am) using red-light; they are cut and taken to the dark room for chlorophyll fluorescence measurements using a fluorometer (FP100).

Nicole collects the leaves and takes them to the dark room for measurements at different temperatures.

From each leaf 8 disks are taken for chlorophyll fluorescence parameters measurements at different temperatures.

Leaf disks are weight before and after drying them in the oven. This data is used for leaf mass per area calculations.

Nicole weighing the samples after all measurements have been performed and the disks have been in the oven for 2-3 days.

20 cm soil collar

Isabel Loza and Iana Grullon-Penkova marking the locations for the soil collars in the study site.

William Mejia installing one of the soil collars for soil gas flux measurements.

Thirty soil collars were placed along the study site.

Isabel Loza next to the first installed soil collar.

Offset measurements were taken on the inside of each collar in the 4 cardinal points.

A test run was performed to assess chamber functioning.

Rain events are common in a tropical rainforest.

Survey chambers are used to perform rapid soil gas flux measurements over multiple locations facilitating spatial variability data collection.

William Mejia carrying the LI8100A and the survey chamber to the next collar.

Iana Grullon-Penkova recording soil gas flux measurements for spatial heterogeneity assessments.

Isabel Loza moving between soil collars to perform soil gas flux measurements using the survey chamber.

20 cm soil collar

Isabel Loza and Iana Grullon-Penkova marking the locations for the soil collars in the study site.

William Mejia installing one of the soil collars for soil gas flux measurements.

Thirty soil collars were placed along the study site.

Isabel Loza next to the first installed soil collar.

Offset measurements were taken on the inside of each collar in the 4 cardinal points.

A test run was performed to assess chamber functioning.

Rain events are common in a tropical rainforest.

Survey chambers are used to perform rapid soil gas flux measurements over multiple locations facilitating spatial variability data collection.

William Mejia carrying the LI8100A and the survey chamber to the next collar.

Iana Grullon-Penkova recording soil gas flux measurements for spatial heterogeneity assessments.

Isabel Loza moving between soil collars to perform soil gas flux measurements using the survey chamber.

William Mejia splitting the ingrowth core soil for root picking.

Sometimes fun acquaintances are found in the soil.

Roots are sorted for 10 minutes initially (for root specific respiration) and 10 additional minutes after that.

The objective is to take out as many roots as possible.

Root specific respiration measurements, performed by Nicole Gutierrez, are done at 3 different temperatures.

All roots are cleaned and sorted into coarse or fine, dead or live. Iana Grullon-Penkova cleans roots after root specific respiration measurements have been performed on them.

Nicole Gutierrez sorting roots into live and dead.

Clean and divided roots.

Iana Grullon-Penkova scans fine live roots for root traits analysis.

Roots are scanned cleaned (without soil). Length, diameter, and volume parameters are extracted from the resulting images.

Nicole Gutierrez weights a subsample of soil for nutrient extractions.

A subsample of 5g of soil is analyzed for multiple nutrients.

Isabel Loza preparing the filtration unit for nutrient extractions.

Reagents for the nutrient extractions. KCl, K2SO4, and Bray.

Soil samples in different flasks awaiting to be used for nutrient extractions.

Samples ventilating in an open space.

Isabel Loza in the filtering station performing nutrient extractions.

In-growth cores are washed and weight after each day extraction from the ground.

Remaining soil is placed in cloth bags for air drying and post subsampling.

Nicole Gutierrez organizing soil and root samples for further processing.

Iana Grullon-Penkova grinding soil samples for archive storage and further analysis.

Root and soil samples are ground and stored into shell vials.

William Mejia storing soil ground samples.

William Mejia splitting the ingrowth core soil for root picking.

Sometimes fun acquaintances are found in the soil.

Roots are sorted for 10 minutes initially (for root specific respiration) and 10 additional minutes after that.

The objective is to take out as many roots as possible.

Root specific respiration measurements, performed by Nicole Gutierrez, are done at 3 different temperatures.

All roots are cleaned and sorted into coarse or fine, dead or live. Iana Grullon-Penkova cleans roots after root specific respiration measurements have been performed on them.

Nicole Gutierrez sorting roots into live and dead.

Clean and divided roots.

Iana Grullon-Penkova scans fine live roots for root traits analysis.

Roots are scanned cleaned (without soil). Length, diameter, and volume parameters are extracted from the resulting images.

Nicole Gutierrez weights a subsample of soil for nutrient extractions.

A subsample of 5g of soil is analyzed for multiple nutrients.

Isabel Loza preparing the filtration unit for nutrient extractions.

Reagents for the nutrient extractions. KCl, K2SO4, and Bray.

Soil samples in different flasks awaiting to be used for nutrient extractions.

Samples ventilating in an open space.

Isabel Loza in the filtering station performing nutrient extractions.

In-growth cores are washed and weight after each day extraction from the ground.

Remaining soil is placed in cloth bags for air drying and post subsampling.

Nicole Gutierrez organizing soil and root samples for further processing.

Iana Grullon-Penkova grinding soil samples for archive storage and further analysis.

Root and soil samples are ground and stored into shell vials.

William Mejia storing soil ground samples.

The LICOR 6800 attached to a leaf at one of our experimental plots.

Nicole Gutierrez leaving the office for the field to perform plant physiology measurements during her photosynthesis campaign.

Nicole Gutiérrez-Ramos (our plant physiology technician) working at one of our control plots. She is taking gas exchange measurements of the internal processes occuring in plants, using the LI-6800; particularly Nicole is working on A-Ci curves.

LICOR 6800 console during settup.

LI6800 attached to a leaf at one of our control plots.

The LICOR 6800 attached to a leaf at one of our experimental plots.

Nicole Gutierrez leaving the office for the field to perform plant physiology measurements during her photosynthesis campaign.

Nicole Gutiérrez-Ramos (our plant physiology technician) working at one of our control plots. She is taking gas exchange measurements of the internal processes occuring in plants, using the LI-6800; particularly Nicole is working on A-Ci curves.

LICOR 6800 console during settup.

LI6800 attached to a leaf at one of our control plots.

Sabana Field Research Station after 3 years from Hurricane Maria.

Our experimental site entrance looks very different from that before the hurricane.

Looking up towards the canopy you can notice a progressive closing. Hurricane Maria completely eliminated the forest canopy.

A new forest is emerging, with a very different structure and composition.

Before you could see across the plots, now we have adapted the project to the new and rising vegetation.

El Yunque National Forest entrance after 3 years from Hurricane Maria.

Sabana Field Research Station after 3 years from Hurricane Maria.

Our experimental site entrance looks very different from that before the hurricane.

Looking up towards the canopy you can notice a progressive closing. Hurricane Maria completely eliminated the forest canopy.

A new forest is emerging, with a very different structure and composition.

Before you could see across the plots, now we have adapted the project to the new and rising vegetation.

El Yunque National Forest entrance after 3 years from Hurricane Maria.

The inside of a clear acrylic minirhizotron sampling tube, this tube was broken due to hurricane damage.

Coqui frog living inside the minirhizotron sampling tube.

Broken minirhizotron sampling tube at one of our experimental plots.

William Mejia (general technician) holds the extracted broken minirhizotron sampling tube.

New minirhizotron sampling tube installed at a 44 deg angle.

The inside of a clear acrylic minirhizotron sampling tube, this tube was broken due to hurricane damage.

Coqui frog living inside the minirhizotron sampling tube.

Broken minirhizotron sampling tube at one of our experimental plots.

William Mejia (general technician) holds the extracted broken minirhizotron sampling tube.

New minirhizotron sampling tube installed at a 44 deg angle.

William Mejia coring one of our soil pits for the installation of sensors.

William Mejia installing oxygen sensors at our soil pits

Megan Berberich installing soil moisture and temperature sensors in one of our 1 meter deep soil pits.

Soil pit instrumentation done by William Mejia.

William Mejia coring one of our soil pits for the installation of sensors.

William Mejia installing oxygen sensors at our soil pits

Megan Berberich installing soil moisture and temperature sensors in one of our 1 meter deep soil pits.

Soil pit instrumentation done by William Mejia.

Rob Tunison (graduate student) taking measurements during the dark respiration campaign.

Dark respiration campaign

Nicole Gutiérrez (plant physiology technician) operating the LI6800 during the dark respiration campaign.

Dark respiration campaign

LI6800 Portable Photosynthesis System

Rob Tunison operating the LI6800.

Rob Tunison (graduate student) taking measurements during the dark respiration campaign.

Dark respiration campaign

Nicole Gutiérrez (plant physiology technician) operating the LI6800 during the dark respiration campaign.

Dark respiration campaign

LI6800 Portable Photosynthesis System

Rob Tunison operating the LI6800.

Ingrowth core soil after root extraction.

Intern Wendy Colon scanning roots.

William Mejia weighing a recently extracted soil ingrowth core.

New root respiration measurement machine.

Graduate student Robert Tunison measures root specific respiration.

Ingrowth core campaign team.

Root picking, sorting and cleaning - From left to right: Iana Grullon-Penkova, Robert Tunison, Wendy Colon.

Ingrowth core soil after root extraction.

Intern Wendy Colon scanning roots.

William Mejia weighing a recently extracted soil ingrowth core.

New root respiration measurement machine.

Graduate student Robert Tunison measures root specific respiration.

Ingrowth core campaign team.

Root picking, sorting and cleaning - From left to right: Iana Grullon-Penkova, Robert Tunison, Wendy Colon.

Intern Wendy Colon holding a white snake from the pile of soil removed from the soil pits.

William Mejia (general technician) and interns Wendy Colon and Maria Ferrer filling the previously sampled soil pits.

William Mejia, Wendy Colon and Maria Ferrer standing inside of one of our three soil pits.

William Mejia, Wendy Colon and Maria Ferrer compacting soil inside the pits.

Intern Wendy Colon holding a white snake from the pile of soil removed from the soil pits.

William Mejia (general technician) and interns Wendy Colon and Maria Ferrer filling the previously sampled soil pits.

William Mejia, Wendy Colon and Maria Ferrer standing inside of one of our three soil pits.

William Mejia, Wendy Colon and Maria Ferrer compacting soil inside the pits.