Stomatal conductance and gas exchange in four species of Caribbean mangroves exposed to ambient and increased CO2

1998 ◽  
Vol 49 (4) ◽  
pp. 325 ◽  
Author(s):  
Samuel C. Snedaker ◽  
Rafael J. Araújo
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
South Florida ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Conocarpus Erectus ◽  
Sun Leaves ◽  
Ambient Co2

Stomatal conductance and gas exchange rates in sun leaves were measured in multiple individuals of four species of Caribbean mangroves common to south Florida, USA. Under ambient CO2 levels (340–360 ppm), stomatal conductance (mol m-2 s-1), net primary productivity (g CO2 m-2 min-1), transpiration (g H2O m-2 s-1), and instantaneous transpiration efficiency, ITE, (µmol CO2/mmol H2O) were not significantly different among the four species: Rhizophora mangle (Rm), Avicennia germinans (Ag), Laguncularia racemosa (Lr), and Conocarpus erectus (Ce). Under exposure to increased CO2 (361–485 ppm) there were highly significant (P < 0.001) decreases in stomatal conductance and transpiration, and a highly significant increase in ITE in all four species. However, there was no significant change in net primary productivity in Rm, Ag and Ce, whereas there was a significant decrease (P < 0.01) in net primary productivity in Lr.

scholarly journals Does insect herbivory suppress ecosystem productivity? Evidence from a temperate woodland

2021 ◽  
Author(s):  
Kristiina Visakorpi ◽  
Sofia Gripenberg ◽  
Yadvinder Malhi ◽  
Terhi Riutta
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Leaf Gas Exchange ◽  
Insect Herbivory ◽  
Ecosystem Productivity ◽  
Area Loss ◽  
Leaf Area Loss ◽  
The Relationship

AbstractOur current understanding of the relationship between insect herbivory and ecosystem productivity is limited. Previous studies have typically quantified only leaf area loss, or have been conducted during outbreak years. These set-ups often ignore the physiological changes taking place in the remaining plant tissue after insect attack, or may not represent typical, non-outbreak herbivore densities. Here, we estimate the amount of carbon lost to insect herbivory in a temperate deciduous woodland both through leaf area loss and, notably, through changes in leaf gas exchange in non-consumed leaves under non-outbreak densities of insects. We calculate how net primary productivity changes with decreasing and increasing levels of herbivory, and estimate what proportion of the carbon involved in the leaf area loss is transferred further in the food web. We estimate that the net primary productivity of an oak stand under ambient levels of herbivory is 54 - 69% lower than that of a completely intact stand. The effect of herbivory quantified only as leaf area loss (0.1 Mg C ha−1 yr−1) is considerably smaller than when the effects of herbivory on leaf physiology are included (8.5 Mg C ha−1 yr−1). We propose that the effect of herbivory on primary productivity is non-linear and mainly determined by changes in leaf gas exchange. We call for replicated studies in other systems to validate the relationship between insect herbivory and ecosystem productivity described here.

scholarly journals Índices de vegetación y unidades de paisaje de la Reserva de Fauna Silvestre Ciénaga de La Palmita e Isla de Pájaros, estado Zulia, Venezuela

Revista Alfa ◽  
2020 ◽  
Vol 4 (11) ◽  
pp. 157-169
Author(s):  
Antonio Vera ◽  
Gustavo Morillo ◽  
Darisol Pacheco
Keyword(s):  
Rhizophora Mangle ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Landsat 8 ◽  
Conocarpus Erectus

Se determinaron los índices de vegetación y las unidades de paisaje de la Reserva de Fauna Silvestre Ciénaga de La Palmita e Isla de Pájaros, empleando imágenes LANDSAT 8 (2013-2016) y el NDVI usando el programa ENVI. Se identificaron siete unidades de paisaje. El espejo de agua mostró un NDVI bajo (0,00-0,03), asociado al muy escaso vigor vegetal y el borde ciénaga-porción terrestre presentó 0,04-0,08 vinculado a los primeros indicios de productividad. Los suelos fangosos-desnudos revelaron 0,09-0,16 relacionado a escasas capas de fitoplancton. Las comunidades xerófilas intervenidas presentaron 0,17-0,24 contrastando con 0,25-0,28 de las formaciones xerófilas, espinosas y semideciduas bajas. Las comunidades de Avicennia germinans, Conocarpus erectus y Laguncularia racemosa mostraron 0,29-0,39 debido al bajo porte e individuos muertos; y Rhizophora mangle reveló 0,4-0,55, vinculado con la altura arborea, dosel semicerrado, pocos claros y verdor foliar intenso-brillante. Las unidades variaron desde comunidades xerófilas intervenidas hasta comunidades de R. mangle relativamente bien conservadas.

Gas Exchange, Photosynthetic Uptake, and Carbon Budget for a Radiocarbon Addition to a Small Enclosure in a Stratified Lake

1980 ◽  
Vol 37 (3) ◽  
pp. 464-471 ◽  
Author(s):  
Peter Bower ◽  
Daniel McCorkle
Keyword(s):  
Mass Transfer ◽  
Gas Exchange ◽  
Primary Productivity ◽  
Carbon Budget ◽  
Inorganic Carbon ◽  
Net Primary Productivity ◽  
Dissolved Inorganic Carbon ◽  
Dark Respiration ◽  
Late Summer ◽  
Transfer Coefficients

9250 kBq (250 μCi) of 14C as NaHCO3 were added to the mixed-layer waters inside a long, cylindrical plastic enclosure anchored in an oligotrophic lake of the Canadian Shield. Loss of 14C from the epilimnion was predominantly in the form of irreversible gas-exchange across the liquid–air interface. This loss was measured by 14C inventory of the epilimnion and thermocline waters. Using the Lewis and Whitman boundary layer model, values for the mass transfer coefficient of 126, 58, and 100 cm/d were determined for three distinct phases in the deepening of the epilimnion during autumn cooling. The relationship between these mass transfer coefficients and the average wind speeds over the same three time periods were consistent with the results of previous wind-tunnel, gas-exchange experiments.Two significant features of the carbon budget during the course of the experiment were the large net outflux of CO2 from the corral (with [Formula: see text] in the epilimnion 3–7 times atmospheric levels) and the doubling of the total dissolved inorganic carbon (DIC) content of the epilimnion. The major source of carbon for these two processes was the entrainment of dissolved inorganic carbon as the epilimnion deepened during the cool days of late summer. Particulate organic carbon was also entrained and its oxidation contributed to the net DIC increase and CO2 loss. Simultaneous determinations of daily integral primary productivity by an incubator technique and by direct measurement of 14C uptake inside the enclosure were consistent. Dark respiration was 45–53% of daily integral primary productivity, but total respiration was nearly two times that for dark plus light respiration. Net primary productivity was thus substantially negative.Key words: Gas exchange, photosynthetic uptake, carbon budget

scholarly journals Annual net primary productivity of a cyanobacteria dominated biological soil crust in the Gulf savanna, Queensland, Australia

2017 ◽  
Author(s):  
Burkhard Büdel ◽  
Wendy J. Williams ◽  
Hans Reichenberger
Keyword(s):  
Gas Exchange ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Heterotrophic Bacteria ◽  
Biological Soil Crust ◽  
Net Photosynthesis ◽  
Common Element ◽  
Carbon Gain ◽  
Active Period ◽  
Soil Crust

Abstract. Biological soil crusts are a common element of the Queensland (Australia) dry savannah ecosystem and are composed of cyanobacteria, algae, lichens, bryophytes, fungi and heterotrophic bacteria. Here we report on the annual net primary productivity of a cyanobacteria dominated biological soil crust form the Boodjamulla National Park in north western Queensland using a semi-automatic cuvette system. The dominating cyanobacteria are the filamentous species Sypmplocastrum purpurascens together with Scytonema sp. The recording period lasted from July 1st 2010 to June 30th 2011. Metabolic activity was found from November 2010 until mid-April 2011 only, referring to 23.6 % of the total time of the year. With the onset of the raining season in November, the first month of activity had a pronounced respiratory loss of CO2. Also the last month of the raining season had a negative CO2 balance. Of the metabolic active period, 48.6 % were net photosynthesis and 51.4 % dark respiration. Net photosynthetic uptake of CO2 during daylight was reduced at 32.6 % of the time by water suprasaturation during. In total, the biological soil crust fixed 229.09 mmol CO2 m−2 yr−1, referring to an annual carbon gain of 2.75 g m−2 yr−1. Due to malfunction of the automatic cuvette system, data from September and October 2010, together with days in November and December 2010 could not be analysed for net photosynthesis and respiration. Based on climatic and gas exchange data from November 2010, an estimated loss of 88 mmol CO2 m−2 was found for the two month, resulting in annual rates of 143.08 mmol CO2 m−2 yr−1, equivalent to a carbon gain of 1.72 g m−2 yr−1. The bulk net photosynthetic activity occurred above a relative humidity above 42 %, indicating a suitable climatic combination of temperature and water availability, and a light intensity well above 200 µmol photons m−2 s−1 photosynthetic active radiation. The Boodjamulla biocrust showed a highly seasonally varying CO2 gas exchange pattern divided into metabolically inactive winter month and active summer month. The metabolic active period starts with a period (up to 3 month) of carbon loss, probably due to regrowth before a four month period of carbon gain. This must be taken into consideration for future analyses and modelling of carbon balances in comparable biocrust ecosystems.

scholarly journals THE RECOVERY OF A DEGRADED MANGROVE IN CEARÁ THROUGH THE PRODUCTION OF Laguncularia racemosa (L.) C.F. Gaertn. (Combretaceae) AND Avicennia sp. Stapf ex Ridl (Acanthaceae) SEEDLINGS

2016 ◽  
Vol 40 (3) ◽  
pp. 377-385 ◽  
Author(s):  
Amanda Lídia de Sousa Paula ◽  
Brena Késia de Sousa Lima ◽  
Rafaela Camargo Maia
Keyword(s):  
Survival Rates ◽  
River Estuary ◽  
Mangrove Ecosystem ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Western Coast ◽  
Mangrove Species ◽  
Growth And Survival ◽  
Conocarpus Erectus

ABSTRACT The mangrove ecosystem performs several natural functions of great ecological and economic importance. This study provided procedures for the recovery of mangrove ecosystems through the characterization of vegetation and zonation patterns and evaluation of growth and survival rates of mangrove species in an experimental plantation. The study was performed in the Acaraú River estuary mangrove on the western coast of Ceará State. The characterization of vegetation was conducted with the use of multiple plots and transects replication. Plants were identified at the species level, and their heights and CBH (circumference at breast height) were measured in each plot. Seedlings of the dominant mangrove species were produced using estuarine propagules. Five mangrove species were sampled: Rhizophora mangle, Avicennia germinans, Avicennia schaueriana, Laguncularia racemosa, and Conocarpus erectus. L. racemosa was the most dominant and frequent species, followed by A. germinas. A total of 111 L. racemosa and 102 Avicennia sp seedlings of were produced. Seedlings were viable for replanting within two months. The results of the analysis of vegetation structure and production and growth of seedlings are encouraging and demonstrate that revegetation is not only possible but also successful in this significantly deforested and degraded mangrove.

scholarly journals Los manglares de Colombia y la recuperación de sus áreas degradadas: revisión bibliográfica y nuevas experiencias

2016 ◽  
Vol 9 (1) ◽  
pp. 3-25 ◽  
Author(s):  
Ricardo Álvarez-León
Keyword(s):  
Rhizophora Mangle ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Conocarpus Erectus ◽  
Pelliciera Rhizophorae

Se revisa el estado actual de los rodales de manglar y las experiencias silviculturales logradas en las costas colombianas con las especies presentes en el Caribe (Avicennia germinans, Conocarpus erectus, Laguncularia racemosa, Pelliciera rhizophorae y Rhizophora mangle) y las especies del Pacífico (A. germinans, P. rhizophorae, R. spp.). La mayoría de la información existente corresponde al conocimiento del mangle rojo (R. mangle), lo que en parte se debe a su mecanismo de propagación. Le siguen en orden descendente: C. erectus que se usa masivamente en ornamentación y paisajismo y A. germinans, especie de importancia básica en la dinámica sucesional de suelos salinos y playas áridas, así como en los estudios fisiológicos debido a su tolerancia a la sal. El conocimiento complementario de las otras especies como L. racemosa, Mora oleifera y P. rhizophorae, así como las medidas gubernamentales de protección, contribuirán al manejo integral y sustentable de estos valiosos ecosistemas.

scholarly journals Flujo de materia en un manglar de la costa de Chiapas, México

2016 ◽  
Vol 10 ◽  
pp. 45-61
Author(s):  
D. Edith Orihuela Belmonte ◽  
Cristian Tovilla Hernández ◽  
Henricus Franciscus M. Vester ◽  
Teresa Álvarez Legorreta
Keyword(s):  
Rhizophora Mangle ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Conocarpus Erectus ◽  
El Sistema

La importancia de los sistemas de manglar como fuente de ingreso económico para las comunidades humanas reside en la función que desempeñan como refugio y hábitat para una gran diversidad de organismos acuáticos y terrestres. Con el objetivo de contribuir a un plan de manejo en el sistema Lagunar Pampa Murillo se construyó un modelo del flujo de materia dentro y hacia afuera del manglar con base en estudios de producción de hojarasca, herbivoría, degradación de hojas y exportación de detritus hacia la zona marina. De enero a octubre se realizaron los estudios en cuatro especies de mangle: Rhizophora mangle, Laguncularia racemosa, Avicennia germinans y Conocarpus erectus. En este sistema la producción diaria de hojarasca fue 3,9 g/m2, lo que equivale a 7,9 t C/ha, el porcentaje de consumo en peso sobre las hojas realizado por los herbívoros fue de 13,6 % en A. germinans, 12,5 % en L. racemosa, 9,8 % en R. mangle y 5,7 % C. erectus. La especie más resistente a la degradación fue C. erectus, que en 210 días perdió menos de 50 % de la materia orgánica inicial contenida en las hojas; mientras que A. germinans en el mismo tiempo perdió 87,6 % de la materia orgánica. De la productividad del bosque, el sistema exporta 0,5 t de peso seco/hora de detritus en el mes de mayo; mientras en octubre se eleva a 1,5 t/h (peso seco), para un total de 4 822,2  t C/año que salen del sistema con 54,5 % de materia orgánica, constituyendo un subsidio alimenticio para la zona marina adyacente.

scholarly journals Description of the Panamá and Iguanita mangrove stands of Bahía Culebra, North Pacific coast of Costa Rica

2015 ◽  
Vol 60 (6) ◽  
pp. 109 ◽  
Author(s):  
Jimena Samper-Villarreal ◽  
Jorge Cortés ◽  
Catalina Benavides-Varela
Keyword(s):  
Costa Rica ◽  
North Pacific ◽  
Pacific Coast ◽  
Rhizophora Mangle ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Conocarpus Erectus

Los manglares son abundantes e importantes ecosistemas marino-costeros en Costa Rica pero están siendo afectados por la actividad humana. Se analizó la estructura y cobertura de ambos manglares presentes en Bahía Culebra (Panamá e Iguanita), Guanacaste, Pacífico norte de Costa Rica. Se utilizó el PCQM para estructura durante la época seca entre diciembre 2007 y marzo 2008. Se utilizaron dos imágenes MASTER CARTA 2005 georreferenciadas para mapeo. El área aproximada de bosque de manglar en Panamá fue de 13.7ha; y de 40.8ha en Iguanita. Panamá contiene 51% de manglar denso en el área de estudio, 35% bosque seco, 2% sin vegetación y 12% de arena o agua. En Iguanita el 84% del área corresponde a manglar denso, 5% manglar de baja densidad y 10% sin cobertura vegetal o era arena o agua. Se hallaron cinco especies de manglar en Panamá (<em>Avicennia germinans, Avicennia bicolor, Conocarpus erectus, Laguncularia racemosa y Rhizophora mangle</em>); y tres en Iguanita (<em>A. germinans, L. racemosa y R. mangle</em>). En general, la presencia de las especies de manglar siguió un patrón similar en ambos manglares. La densidad total fue menor que en manglares cercanos; y Panamá (8.4tallos/0.1ha) mucho menor que Iguanita (67.2tallos/0.1 ha). El Índice de Complejidad (IC) fue mucho mayor en Iguanita (IC= 86.5), con dominancia de R. mangle, que en Panamá (IC= 1.1), con dominancia marcada de A. germinans. Estructuralmente ambos manglares son muy distintos entre sí y parecen encontrarse en contextos hidrodinámicos diferentes.

Carbon Isotope Discrimination and Photosynthetic Gas Exchange in Coffee Hedgerows During Canopy Development

1994 ◽  
Vol 21 (2) ◽  
pp. 207 ◽  
Author(s):  
MV Gutierrez ◽  
FC Meinzer
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Isotope ◽  
Carbon Isotope Discrimination ◽  
Area Index ◽  
Canopy Development ◽  
Isotope Discrimination ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Sun Leaves

In evergreen species, leaf carbon isotope discrimination (Δ) integrates phenological rhythms in gas exchange as well as seasonal changes in environmental conditions. However, few reports on long term variations in Δ of woody plants are available. We measured Δ, gas exchange, nitrogen content, and photosynthetic nitrogen-use efficiency (PNUE) in coffee hedgerows at different stages of canopy development encompassing a range of leaf area index (LAI) from 0.7 to 7.5. Assimilation was highest in sun leaves, but stomatal conductance was highest in shaded leaves. This resulted in a high correlation between assimilation and stomatal conductance in sun, but not in shaded leaves. Δ was about 20 lower in sun than in shaded leaves, and varied by 2.30 among leaves at different positions along two-year- old branches. These differences in Δ were the result of changes in carbon isotope composition that occurred in mature, fully expanded leaves as they became shaded during subsequent canopy growth. Results from a mass balance model based on leaf gas exchange characteristics and measured foliar Δ values suggested that about 50% of the carbon originally fixed during leaf development in the sun may have subsequently been turned over in the shade. Δ of sun leaves from the upper canopy decreased by about 20 with increasing LAI, indicating that intrinsic water-use efficiency (WUE) of this canopy layer increased during canopy development. In contrast, instantaneous WUE, estimated as assimilation divided by canopy transpiration obtained from sap flow measurements, seemed to decrease with increasing LAI. PNUE of upper canopy sun leaves decreased with increasing LAI, suggesting a physiological compromise between WUE and PNUE mediated by stomatal conductance, which also decreased with increasing LAI. A strong negative correlation obtained between leaf Δ and N content was consistent with a trade-off between intrinsic water- and N-use efficiency.

scholarly journals Global uptake of carbonyl sulfide (COS) by terrestrial vegetation: Estimates corrected by deposition velocities normalized to the uptake of carbon dioxide (CO<sub>2</sub>)

2005 ◽  
Vol 2 (2) ◽  
pp. 125-132 ◽  
Author(s):  
L. Sandoval-Soto ◽  
M. Stanimirov ◽  
M. von Hobe ◽  
V. Schmitt ◽  
J. Valdes ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Carbonyl Sulfide ◽  
Co2 Assimilation ◽  
Terrestrial Vegetation ◽  
Dark Light ◽  
Global Estimate ◽  
Productivity Data ◽  
Deposition Velocities

Abstract. COS uptake by trees, as observed under dark/light changes and under application of the plant hormone abscisic acid, exhibited a strong correlation with the CO2 assimilation rate and the stomatal conductance. As the uptake of COS occurred exclusively through the stomata we compared experimentally derived and re-evaluated deposition velocities (Vd; related to stomatal conductance) for COS and CO2. We show that Vd of COS is generally significantly larger than that of CO2. We therefore introduced this attribute into a new global estimate of COS fluxes into vegetation. The new global estimate of the COS uptake based on available net primary productivity data (NPP) ranges between 0.69-1.40 Tga-1. However, as a COS molecule is irreversibly split in contrast to CO2 which is released again by respiration processes, we took into account the Gross Primary Productivity (GPP) representing the true CO2 leaf flux the COS uptake has to be related to. Such a GPP based deposition estimate ranged between 1.4-–2.8 Tga-1 (0.73-1.50 TgSa-1). We believe that in order to obtain accurate global COS sink estimates such a GPP-based estimate corrected by the different deposition velocities of COS and CO2 must be taken into account.

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