Responses of CO2 Exchange and Primary Production of the Ecosystem Components to Environmental Changes in a Mountain Peatland

Seagrasses are unique marine flowering plants that play an important ecological role by yielding primary production and carbon sequestration to the marine environment. Seagrass ecosystems are rich in organic matter, supporting the growth of bio-medically important epi and endophytic microorganisms and harbor rich marine biodiversity. They are an essential food source for endangered Andaman state animal Dugongs. Seagrasses are very sensitive to water quality changes, and therefore they serve as ecological bio-indicators for environmental changes. The benthic components in and around the seagrass beds support a significant food chain for other Micro and organisms apart from fishery resources. The epiphytic bacterial communities of the leaf blades support the sustenance against the diseases. Recent reports have shown that the loss of seagrass beds in tropical and temperate regions emphasizes the depletion of these resources, and proper management of seagrass is urgent. The decline of seagrass will impact primary production, biodiversity, and adjacent ecosystems, such as reefs. Therefore, restoring the seagrass meadows could be possible with effective implementing management programs, including seagrass meadows in marine protected areas, restoration projects, seagrass transplantation, implementation of legislative rules, monitoring coastal water quality and human activities in the coastal zone. Lacunas on the seagrass ecosystem management in Andaman & Nicobar Islands are addressed.

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Short-term Effects of Grazing Exclusion on Net Ecosystem CO2 Exchange and Net Primary Production in a Pannonian Sandy Grassland

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4028300 ◽

2012 ◽

Vol 40 (2) ◽

pp. 67 ◽

Cited By ~ 4

Author(s):

Szilard CZOBEL ◽

Orsolya SZIRMAI ◽

Zoltan NEMETH ◽

Csaba GYURICZA ◽

Judit GAZI ◽

...

Keyword(s):

Carbon Sequestration ◽

Primary Production ◽

Net Primary Production ◽

Plant Productivity ◽

Co2 Exchange ◽

Co2 Uptake ◽

Aboveground Phytomass ◽

Grazing Exclusion ◽

Sequestration Potential ◽

Sandy Grassland

Using portable, non-destructive own developed chambers (d=60 cm) and infrared gas analyses, the in situ field investigation was performed to study the seasonal and inter-annual dynamics of the stand level CO2-flux and production of sandy grassland that has been extensively grazed for decades. Furthermore, NEE measurements and biomass samples were used to identify the initial effects of grazing exclusion on CO2 exchange, aboveground phytomass and potential plant productivity in years of significantly different precipitation levels. A considerable inter-annual variation in all of the studied parameters was found both in the non-grazed and grazed stands. As a result of the grazing exclusion the CO2 uptake potential of the non-grazed stand increased by 13% compared to the grazed stand. It was more significant in the extreme dry year (220%), however, in wet year slightly lower average carbon sequestration was detected at the non-grazed stand (-13%), than that of the grazed area. Significant carbon sequestration potential was only detected during wet periods in both stands. The rate of CO2 uptake was found to be nearly six times higher in the non-grazed stand in the wet year than in the previous extremely dry year. The drought in 2003 significantly reduced the CO2 uptake of both stands, leading to lower annual net primary production and potential plant productivity. The annual net primary production dropped by almost 40% in the extremely dry year but then it rose by nearly two and a half times in the subsequent year with adequate rainfall.

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Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland

Global Change Biology ◽

10.1111/gcb.13693 ◽

2017 ◽

Vol 23 (5) ◽

pp. 2140-2140

Keyword(s):

Primary Production ◽

Gross Primary Production ◽

Co2 Exchange

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The Western Maine Coastal Current reduces primary production rates, zooplankton abundance and benthic nutrient fluxes in Massachusetts Bay

ICES Journal of Marine Science ◽

10.1093/icesjms/fst195 ◽

2014 ◽

Vol 71 (5) ◽

pp. 1158-1169 ◽

Cited By ~ 3

Author(s):

M. Conor McManus ◽

Candace A. Oviatt ◽

Anne E. Giblin ◽

Jane Tucker ◽

Jefferson T. Turner

Keyword(s):

Primary Production ◽

Environmental Changes ◽

Monitoring Program ◽

Sediment Oxygen Demand ◽

Nutrient Concentrations ◽

Coastal Current ◽

Zooplankton Abundance ◽

Massachusetts Bay ◽

Production Rates ◽

Annual Primary Production

Abstract Primary production was measured from 1992–2010 in Massachusetts Bay and just outside Boston Harbor for the Massachusetts Water Resources Authority's outfall monitoring program. In 2003, annual primary production decreased by 221–278 g C m−2 year−1, with decreased rates continuing through 2010. Based on a conceptual model, oceanographic and meteorological variables were analysed with production rates to determine if concurrent environmental changes were responsible for the reduced primary production in Massachusetts Bay. Results indicated that a stronger influx of low salinity water from the Western Maine Coastal Current (WMCC) in recent years might be responsible for the decreases. The WMCC appeared to have become fresher due to increased river discharge in the western Gulf of Maine. Northeasterly winds in recent years promoted the WMCC intrusion into Massachusetts Bay. Correlation between primary production and surface salinities suggested an impact of the WMCC on production rates. We hypothesized that increased stratification resulted in reduced vertical mixing and reduced nutrient concentrations in surface waters for phytoplankton growth. However, no significant correlations were observed between the annual primary production and nutrient concentrations in Massachusetts Bay. Reduced production rates in Massachusetts Bay have, however, been associated with reduced zooplankton abundances, benthic ammonium fluxes and sediment oxygen demand in summer months.

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Simulation of Mediterranean forest carbon pools under expected environmental scenarios

Canadian Journal of Forest Research ◽

10.1139/x10-037 ◽

2010 ◽

Vol 40 (5) ◽

pp. 850-860 ◽

Cited By ~ 12

Author(s):

M. Chiesi ◽

M. Moriondo ◽

F. Maselli ◽

L. Gardin ◽

L. Fibbi ◽

...

Keyword(s):

Primary Production ◽

Environmental Changes ◽

Net Primary Production ◽

Gross Primary Production ◽

Central Italy ◽

Forest Carbon ◽

Simulation Approach ◽

Two Factors ◽

Vegetation Carbon ◽

The Impact

Simulating the effects of possible environmental changes on the forest carbon budget requires the use of calibrated and tested models of ecosystem processes. A recently proposed simulation approach based on the use of the BIOME-BGC model was applied to yield estimates of present carbon fluxes and pools in Tuscany forests (central Italy). After the validation of these estimates against existing ground data, the simulation approach was used to assess the impact of plausible climate changes (+2 °C and increased CO2 concentration) on forest carbon dynamics (gross primary production (GPP), net primary production (NPP), and relevant allocations). The results indicate that the temperature change tends to inhibit all production and allocation processes, which are instead enhanced by the CO2 concentration rise. The combination of the two factors leads to a general increase in both GPP and NPP that is higher for deciduous oaks and chestnut (+30% and 24% for GPP and +42% and 31% for NPP, respectively). Additionally, vegetation carbon is slightly increased, while total soil carbon remains almost unchanged with respect to the present conditions. These findings are analyzed with reference to the Tuscany forest situation and previous studies on the subject.

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Global cropland monthly Gross Primary Production in the year 2000

Biogeosciences Discussions ◽

10.5194/bgd-11-3465-2014 ◽

2014 ◽

Vol 11 (2) ◽

pp. 3465-3488

Author(s):

T. Chen ◽

G. R. van der Werf ◽

N. Gobron ◽

E. J. Moors ◽

A. J. Dolman

Keyword(s):

Primary Production ◽

Survey Data ◽

Land Surface ◽

Gross Primary Production ◽

Co2 Exchange ◽

Light Use Efficiency ◽

Natural Ecosystems ◽

Use Efficiency ◽

Crop Types ◽

Year 2000

Abstract. Croplands cover about 12% of the ice-free terrestrial land surface. Compared with natural ecosystems, croplands have distinct characteristics due to anthropogenic influences. Their global gross primary production (GPP) is not well constrained and estimates vary between 8.2 and 14.2 Pg C yr−1. We quantified global cropland GPP using a light use efficiency (LUE) model, employing satellite observations and survey data of crop types and distribution. A novel step in our analysis was to assign a maximum light use efficiency estimate (&varepsilon;&ast;GPP) to each of the 26 different crop types, instead of taking a uniform value as done in the past. These &varepsilon;&ast;GPP values were calculated based on flux tower CO2 exchange measurements and a literature survey of field studies, and ranged from 1.20 g CMJ−1 to 2.96 g CMJ−1. Global cropland GPP was estimated to be 11.05 Pg C yr−1 in the year 2000. Maize contributed most to this (1.55 Pg C yr−1), and the continent of Asia contributed most with 38.9% of global cropland GPP. In the continental United States, annual cropland GPP (1.28 Pg C yr−1) was close to values reported previously (1.24 Pg C yr−1) constrained by harvest records, but our estimates of &varepsilon;&ast;GPP values were much higher. Our results are sensitive to satellite information and survey data on crop type and extent, but provide a consistent and data-driven approach to generate a look-up table of &varepsilon;&ast;GPP for the 26 crop types for potential use in other vegetation models.

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Various responses of pine marten morphology and demography to temporal climate changes and primary productivity

10.21203/rs.3.rs-1021314/v1 ◽

2021 ◽

Author(s):

Anna Wereszczuk ◽

Anastasia Fedotova ◽

Adrian Marciszak ◽

Marcin Popiołek ◽

Arsenia Zharova ◽

...

Keyword(s):

Climate Change ◽

Body Size ◽

Sex Ratio ◽

Primary Production ◽

Primary Productivity ◽

Environmental Changes ◽

Time Lag ◽

Time Lags ◽

Pine Marten ◽

Over Time

Abstract Climate and environmental changes affect species’ morphology and ecology; however, the response of a species to changes in abiotic and biotic factors is not always consistent. Here, we tested how the structural body size of the pine marten and its population sex ratio changed over time and alongside climate change. We analysed temporal changes in morphological traits using 11 measurements of pine marten skulls collected between 1903 to 2020, linking them with climatic and primary production variations. We assessed demographic changes by calculating temporal sex ratio changes over 61 years. Skull size, as a proxy of body size, increased in response to warmer and less snowy winters, with a three-year time-lag. However, changes in primary productivity rapidly shaped postorbital constriction regardless of body size changes and without time-lags, potentially demonstrating increased diet diversity in pine marten. According to climate change, the population sex ratio has skewed towards males over time. Our results suggest that climate conditions and primary production affect skull structural size, highlighting the potential various responses of pine marten morphology and ecology in relation to climate change. Recently changing population demographics, as a consequence of these processes, may constitute a threat to marten populations.

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Dynamic changes of terrestrial net primary production and its feedback to evapotranspiration

10.5194/hess-2016-87 ◽

2016 ◽

Author(s):

Zhi Li ◽

Yaning Chen ◽

Yang Wang ◽

Gonghuan Fang

Keyword(s):

Primary Production ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Environmental Changes ◽

Water Cycle ◽

Net Primary Production ◽

Positive Trend ◽

Precipitation Trend ◽

Vegetation Productivity ◽

Increased Risk

Abstract. Earth experienced dramatic environmental changes in the recent 15 years (2000–2014). The past decade has been the warmest in the instrumental record, which significantly influences the global water cycle and vegetation activities. Overall, the global inter-annual series of net primary production (NPP) slightly increased in 2000–2014 at a rate of 0.06 PgC/yr2. More than 64 % of vegetated land in the Northern Hemisphere showed increased net primary production, while 60.3 % of vegetated land in the Southern Hemisphere showed decreased trend. Net primary production correlates positively with land actual evapotranspiration (ET), especially in the Northern Hemisphere, where the increased vegetation productivity (0.13 PgC/yr2) promotes decadal rises of terrestrial evapotranspiration (0.61 mm/yr2). However, anomalous dry conditions led to reduced vegetation productivity (−0.18 PgC/yr2) and nearly ceased growth in terrestrial evapotranspiration in the Southern Hemisphere (0.41 mm/yr2). Under the content of past warmest 15 years, global potential evapotranspiration (PET) shows an increasing trend of 1.72 mm/yr2, while precipitation for the domain shows a variability positive trend of 0.84 mm/yr2, which consistent with expected water cycle intensification. But precipitation trend is lower than evaporative demand, indicating some moisture deficit between available water demand and supply for evapotranspiration, thereby accelerated soil moisture loss. Drought indices and precipitation-minus-evaporation suggested an increased risk of drought in the present century. To understand why climates in the northern and southern hemispheres respond differently to NPP, the results showed that temperature is the dominant control on vegetation growth in the high latitude in the Northern Hemisphere, while net radiation is the main effect factors to NPP in the mid latitude, and in arid and semi-arid biomes also mainly driven by precipitation. While in the Southern Hemisphere, NPP decreased because of warming associated drying trends of PDSI.

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Sea-ice associated carbon flux in Arctic spring

Elem Sci Anth ◽

10.1525/elementa.2020.00169 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

J. Ehrlich ◽

B. A. Bluhm ◽

I. Peeken ◽

P. Massicotte ◽

F. L. Schaafsma ◽

...

Keyword(s):

Sea Ice ◽

Primary Production ◽

Carbon Flux ◽

Secondary Production ◽

Environmental Changes ◽

Ice Algae ◽

Carbon Demand ◽

Algal Material ◽

Source Sink ◽

Ice Water

The Svalbard region faces drastic environmental changes, including sea-ice loss and “Atlantification” of Arctic waters, caused primarily by climate warming. These changes result in shifts in the sea-ice-associated (sympagic) community structure, with consequences for the sympagic food web and carbon cycling. To evaluate the role of sympagic biota as a source, sink, and transmitter of carbon, we sampled pack ice and under-ice water (0–2 m) north of Svalbard in spring 2015 by sea-ice coring and under-ice trawling. We estimated biomass and primary production of ice algae and under-ice phytoplankton as well as biomass, carbon demand, and secondary production of sea-ice meiofauna (>10 µm) and under-ice fauna (>300 µm). Sea-ice meiofauna biomass (0.1–2.8 mg C m–2) was dominated by harpacticoid copepods (92%), nauplii (4%), and Ciliophora (3%). Under-ice fauna biomass (3.2–62.7 mg C m–2) was dominated by Calanus copepods (54%). Appendicularia contributed 23% through their high abundance at one station. Herbivorous sympagic fauna dominated the carbon demand across the study area, estimated at 2 mg C m–2 day–1 for ice algae and 4 mg C m–2 day–1 for phytoplankton. This demand was covered by the mean primary production of ice algae (11 mg C m–2 day–1) and phytoplankton (30 mg C m–2 day–1). Hence, potentially 35 mg C m–2 day–1 of algal material could sink from the sympagic realm to deeper layers. The demand of carnivorous under-ice fauna (0.3 mg C m–2 day–1) was barely covered by sympagic secondary production (0.3 mg C m–2 day–1). Our study emphasizes the importance of under-ice fauna for the carbon flux from sea ice to pelagic and benthic habitats and provides a baseline for future comparisons in the context of climate change.

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Growth increments in teeth of Diictodon (Therapsida)

Koedoe ◽

10.4102/koedoe.v34i1.408 ◽

1991 ◽

Vol 34 (1) ◽

Cited By ~ 5

Author(s):

J. Francis Thackeray

Keyword(s):

Primary Production ◽

South African ◽

Carbon Isotope ◽

Environmental Changes ◽

Isotope Ratios ◽

Late Permian ◽

The South ◽

Carbon Isotope Ratios ◽

Growth Increments ◽

Assemblage Zone

Growth increments circa 0.02 mm in width have been observed in sectioned tusks of Diictodon from the Late Permian lower Beaufort succession of the South African Karoo, dated between about 260 and 245 million years ago. Mean growth increments show a decline from relatively high values in the Tropidostoma/Endothiodon Assemblage Zone, to lower values in the Aulacephalodon/Cistecephaluszone, declining still further in the Dicynodon lacerficeps/Whaitsia zone at the end of the Permian. These changes coincide with gradual changes in carbon isotope ratios measured from Diictodon tooth apatite. It is suggested that the decline in growth increments is related to environmental changes associated with a decline in primary production which contributed to the decline in abundance and ultimate extinction of Diictodon.

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