Estimation of net primary productivity of different forest types based on improved CASA model in Jing-Jin-Ji region, China

2017 ◽  
Vol 36 (6) ◽  
pp. 568-582 ◽  
Author(s):  
Ying Zhang ◽  
Xiaoli Zhang
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Forest Types ◽  
Casa Model

scholarly journals Simulating Spatiotemporal Dynamics of Sichuan Grassland Net Primary Productivity Using the CASA Model and In Situ Observations

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Chuanjiang Tang ◽  
Xinyu Fu ◽  
Dong Jiang ◽  
Jingying Fu ◽  
Xinyue Zhang ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Alpine Meadow ◽  
Growth Period ◽  
Temporal Variations ◽  
Light Use Efficiency ◽  
Important Indicator ◽  
Casa Model ◽  
Use Efficiency

Net primary productivity (NPP) is an important indicator for grassland resource management and sustainable development. In this paper, the NPP of Sichuan grasslands was estimated by the Carnegie-Ames-Stanford Approach (CASA) model. The results were validated with in situ data. The overall precision reached 70%; alpine meadow had the highest precision at greater than 75%, among the three types of grasslands validated. The spatial and temporal variations of Sichuan grasslands were analyzed. The absorbed photosynthetic active radiation (APAR), light use efficiency (ε), and NPP of Sichuan grasslands peaked in August, which was a vigorous growth period during 2011. High values of APAR existed in the southwest regions in altitudes from 2000 m to 4000 m. Light use efficiency (ε) varied in the different types of grasslands. The Sichuan grassland NPP was mainly distributed in the region of 3000–5000 m altitude. The NPP of alpine meadow accounted for 50% of the total NPP of Sichuan grasslands.

Spatial Analysis on the Fluctuation of Regional NPP in the Typical Steppe, in China

2012 ◽  
Vol 518-523 ◽  
pp. 5126-5129 ◽  
Author(s):  
Su Ying Li ◽  
Xiu Mei Wang ◽  
Ying Chang ◽  
Xiao Xia Wu ◽  
Qiang Fan
Keyword(s):  
Energy Efficiency ◽  
Primary Productivity ◽  
Inner Mongolia ◽  
Annual Variation ◽  
Net Primary Productivity ◽  
Average Rate ◽  
Landscape Scale ◽  
Typical Steppe ◽  
Casa Model ◽  
Grassland Productivity

Assessing the inter-annual variation of regional grassland productivity is imperative to meet the local requirements of grassland adaptive management at regional- or landscape- scale. For the semiarid grassland of Inner Mongolia, the improved CASA model, a kind of light-energy-efficiency model, was used to simulate the Net Primary Productivity (NPP) of the regional grassland. And this study further calculated the Standard Deviation (SD) and Coefficient of Variation (CV) of the regional NPP. Both of SD and CV were used to reflect the fluctuations of regional NPP in the study area among years. Approximately 1/3 of the regional NPP over the years were dramatically changed, frequently up to large amplitude by an average rate of 1 times or more.

Relationships between net primary productivity and stand age for several forest types and their influence on China’s carbon balance

2011 ◽  
Vol 92 (6) ◽  
pp. 1651-1662 ◽  
Author(s):  
Shaoqiang Wang ◽  
Lei Zhou ◽  
Jingming Chen ◽  
Weimin Ju ◽  
Xianfeng Feng ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Carbon Balance ◽  
Net Primary Productivity ◽  
Stand Age ◽  
Forest Types

scholarly journals Effects of nutrient availability and other elevational changes on bromeliad populations and their invertebrate communities in a humid tropical forest in Puerto Rico

2000 ◽  
Vol 16 (2) ◽  
pp. 167-188 ◽  
Author(s):  
Barbara A. Richardson ◽  
M. J. Richardson ◽  
F. N. Scatena ◽  
W. H. Mcdowell
Keyword(s):  
Species Richness ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Plant Density ◽  
Nutrient Concentrations ◽  
Forest Types ◽  
Nutrient Inputs ◽  
Nitrogen And Phosphorus ◽  
Faunal Abundance ◽  
High Plant Density

Nutrient inputs into tank bromeliads were studied in relation to growth and productivity, and the abundance, diversity and biomass of their animal inhabitants, in three forest types along an elevational gradient. Concentrations of phosphorus, potassium and calcium in canopy-derived debris, and nitrogen and phosphorus in phytotelm water, declined with increasing elevation. Dwarf forest bromeliads contained the smallest amounts of debris/plant and lowest concentrations of nutrients in plant tissue. Their leaf turnover rate and productivity were highest and, because of high plant density, they comprised 12.8% of forest net primary productivity (0.47 t ha−1 y−1), and contained 3.3 t ha−1 of water. Annual nutrient budgets indicated that these microcosms were nutrient-abundant and accumulated < 5% of most nutrients passing through them. Exceptions were K and P in the dwarf forest, where accumulation was c. 25% of inputs. Animal and bromeliad biomass/plant peaked in the intermediate elevation forest, and were positively correlated with the debris content/bromeliad across all forest types. Animal species richness showed a significant mid-elevational peak, whereas abundance was independent of species richness and debris quantities, and declined with elevation as forest net primary productivity declined. The unimodal pattern of species richness was not correlated with nutrient concentrations, and relationships among faunal abundance, species richness, nutrient inputs and environment are too complex to warrant simple generalizations about nutrient resources and diversity, even in apparently simple microhabitats.

Is the net new carbon increment of coppice forest stands of Quercus ilex ssp. ballota affected by post-fire thinning treatments and recurrent fires?

2010 ◽  
Vol 19 (5) ◽  
pp. 637 ◽  
Author(s):  
Francisco R. López-Serrano ◽  
Jorge De Las Heras ◽  
Daniel Moya ◽  
Francisco A. García-Morote ◽  
Eva Rubio
Keyword(s):  
Primary Productivity ◽  
Quercus Ilex ◽  
Net Primary Productivity ◽  
Terrestrial Ecosystems ◽  
First Year ◽  
Forest Types ◽  
Forest Stands ◽  
Se Spain ◽  
Coppice Forest ◽  
Global Values

Coppice forest stands of Quercus ilex have been one of the forest types most impacted by fire in Spain. After fire, their capability to resprout produces a high density of stems that requires thinning in order to avoid stagnation within the stands. In August 1993 and July 2001, two consecutive fires affected a Quercus ilex coppice stand in SE Spain. This study investigated the effects of different post‐fire thinning treatments and recurrent fires on stock and net new carbon increment (NNCI) in a 6‐year‐old coppice stand. Four degrees of thinning were applied: medium thinning (to a final density of 5000 trees ha–1), drastic thinning (to 1800 trees ha–1), full felling (all trees removed) and no thinning (control). Results showed NNCI was within the lower limit of the average global values reported for net primary productivity of terrestrial ecosystems. The best thinning treatment to maximise both current annual NNCI and mean annual NNCI stimulation, and keep new resprouting within reasonable levels was medium thinning. However, recurrent fires caused the observed net primary productivity to decrease, which allowed us to conclude that stump vitality is affected by successive fires, at least the first year after a new fire.

scholarly journals Response of net primary productivity to grassland phenological changes in Xinjiang, China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10650
Author(s):  
Renping Zhang ◽  
Jing Guo ◽  
Gang Yin
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Growing Season ◽  
Casa Model ◽  
Phenological Changes ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Phenological Metrics ◽  
The Impact

Determining the relationship between net primary productivity (NPP) and grassland phenology is important for an in-depth understanding of the impact of climate change on ecosystems. In this study, the NPP of grassland in Xinjiang, China, was simulated using the Carnegie-Ames-Stanford approach (CASA) model with Moderate Resolution Imaging Spectroradiometer (MODIS) grassland phenological (MCD12Q2) data to study trends in phenological metrics, grassland NPP, and the relations between these factors from 2001–2014. The results revealed advancement of the start of the growing season (SOS) for grassland in most regions (55.2%) in Xinjiang. The percentage of grassland area in which the end of the growing season (EOS) was delayed (50.9%) was generally the same as that in which the EOS was advanced (49.1%). The percentage of grassland area with an increase in the length of the growing season (LOS) for the grassland area (54.6%) was greater than that with a decrease in the LOS (45.4%). The percentage of grassland area with an increase in NPP (61.6%) was greater than that with a decrease in NPP (38.4%). Warmer regions featured an earlier SOS and a later EOS and thus a longer LOS. Regions with higher precipitation exhibited a later SOS and an earlier EOS and thus a shorter LOS. In most regions, the SOS was earlier, and spring NPP was higher. A linear statistical analysis showed that at various humidity (K) levels, grassland NPP in all regions initially increased but then decreased with increasing LOS. At higher levels of K, when NPP gradually increased, the LOS gradually decreased.

Remote sensing estimation and analysis of net primary productivity (NPP) based on corrected CASA model: A case study of Hexi Corridor

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
李传华 LI Chuanhua ◽  
曹红娟 CAO Hongjuan ◽  
范也平 FAN Yeping ◽  
韩海燕 HAN Haiyan ◽  
孙皓 SUN Hao ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Hexi Corridor ◽  
Casa Model

scholarly journals Projection of Net Primary Productivity under Global Warming Scenarios of 1.5 °C and 2.0 °C in Northern China Sandy Areas

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 71 ◽  
Author(s):  
Xiaofei Ma ◽  
Tianci Huo ◽  
Chengyi Zhao ◽  
Wei Yan ◽  
Xun Zhang
Keyword(s):  
Global Warming ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Negative Impact ◽  
Northern China ◽  
Inhibitory Effect ◽  
Emission Scenarios ◽  
Casa Model ◽  
Spatio Temporal ◽  
The Impact

Empirical evidence suggests that variations in climate affect the net primary productivity (NPP) across sandy areas over time. However, little is known about the relative impacts of climate change on NPP with global warming of 1.5 and 2.0 °C (GW_1.5 °C_2.0 °C) relative to pre-industrial levels. Here, we used a new set of climate simulations from four Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP 2b) datasets, modified the Carnegie-Ames-Stanford approach (CASA) model and assessed the spatio-temporal variation in NPP in sandy areas of northern China (SAONC). Compared with the reference period (RP, 1986–2005), the NPP variation under four emission scenarios showed clear rising trends and increased most significantly under RCP8.5 with an annual average increase of 2.34 g C/m2. The estimated annual NPP under global warming of 1.5 °C (GW_1.5 °C) increased by 14.17, 10.72, 8.57, and 26.68% in different emission scenarios, and under global warming of 2.0 °C (GW_2.0 °C) it increased by 20.87, 24.01, 29.31, and 39.94%, respectively. In terms of seasonal change, the NPP value under the four emission scenarios changed most significantly in the summer relative to RP, exhibiting a growth of 16.48%. Temperature changes (p > 0.614) had a greater impact on NPP growth than precipitation (p > 0.017), but solar radiation showed a certain negative impact in the middle- and low-latitude regions. NPP showed an increasing trend that changed from the southeast to the central and western regions at GW_1.5 to GW_2.0 °C. NPP was consistent with the spatial change in climate factors and had a promoting role in high latitudes in SAONC, but it was characterized by a certain inhibitory effect at middle and low latitudes in SAONC. The uncertainty of NPP under the four models ranged from 16.29 to 26.52%. Our findings suggest that the impact of GW_1.5 °C is relatively high compared with the current conditions, whereas GW_2.0 °C implies significantly lower projected NPP growth in all areas.

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