To mitigate the grassland degradation in the Mongolian Plateau (MP), both China and Mongolia governments have carried out a series of new policies and ecological projects. However, the effect of such ...restoration measures on the productivity of grassland in the MP under different political systems remains unclear. Here we study the effects of land use and land cover change, human activities and climate change on the net primary productivity (NPP) of grassland in Mongolia (MG) and Inner Mongolia (IM) from 2001 to 2014. Results showed that the area of grassland increased in both MG and IM, accounted for 4.45 × 104 and 10.31 × 104 km2, respectively. The extended grassland contributed 4.34 × 108 Gg C (Gg = 109 g) to the total NPP, while the loss of grassland led to a decrease of 0.19 × 108 Gg C. The total NPP of grasslands in 2014 increased about 17.88% and 30.49% respectively in MG and IM since 2001. Specifically, IM exhibited a higher increase in land converted NPP than MG. The area of grassland restoration in IM and MG accounted for 90.21% and 81.45%, respectively, indicating that the grassland of the MP was restored. Although human activity was the dominant factor on grassland degradation, which was accounted for 9.79% and 18.55% in IM and MG, it has a positive effect on most of the grassland NPP in the MP. Overall, policy measures and ecological projects in IM brought a more positive effect compared with that in MG.
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•Land use and cover change (LUCC) as one of driving factors was quantified.•Inner Mongolia had a higher increase of land conversion NPP than Mongolia.•Grasslands in most areas of the Mongolian Plateau show a recovery trend.•Human activities are still the dominant factor in promoting degradation in the MP.
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•Accurate assessment of China’s ecological environment changes in the past 20 years is important.•We used time-series NDVI data (1998–2018) to evaluate China’s ecological environment ...change.•In one-third of China the ecological environment has improved, and in 10%, the ecological environment has deteriorated.•The Yellow River Basin is an area where the ecological environment has significantly improved.•The main reason for the deterioration in the ecological environment of the eastern coastal areas is urban expansion.
The ecological environment is the foundation of human survival and development. China’s ecological environment has undergone a historic transition from partial improvement to overall improvement. In this paper, long time series NDVI data (1998–2018) are used to evaluate the ecological environment change and spatiotemporal change that has taken place in China over the last 20 years, at different scales (regional, provincial, county, and grid scales). Combined with typical areas, the causes of ecological environment change are revealed. The results show that in about one-third of China, the ecological environment improved, and in 10%, the ecological environment deteriorated. Ningxia, Shaanxi, Shanxi, Guizhou, and Guangxi are the provinces in which the improvement of the ecological environment is most pronounced. However, the ecological environments with vegetation as the core in Shanghai and Jiangsu Province have deteriorated significantly. The areas with the fastest improvement in their ecological environment are those with precipitation of 200–600 mm. The Yellow River Basin is an area where the ecological environment has significantly improved. Forestry projects and the development of oasis agriculture effectively promote the improvement of the ecological environment. In the past 20 years, the main reason for the degradation of the ecological environment in eastern coastal areas is urban expansion. China should continue to strengthen its overall layout of forestry projects and improve its ecological environment. When planning its ecological construction, China should fully consider the associated physical and geographical conditions, and adjust measures to local conditions accordingly. China should coordinate the relationship between development and protection and avoid the “pie spread” expansion witnessed in eastern coastal areas.
•Vegetation cover in hilly southern China improved and exist spatial heterogeneity.•Residual analysis separated the influence of climate factors and human activities.•Ecological restoration programs ...have positive effect on vegetation.•The adverse effect of drought has offset the benefits of ecological restoration.
Vegetation cover is a commonly used indicator to evaluate terrestrial environmental conditions. Changes in the spatiotemporal patterns of vegetation alter the structures and functions of the landscape, thereby affecting ecological processes. Hilly southern China is an important ecological restoration area, in which the vegetation cover and land use has changed significantly. However, very few studies have considered vegetation changes due to multiple factors in this region. We investigated the spatiotemporal variations in vegetation cover using a Normal Difference Vegetation Index (NDVI) time-series data set obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) and climate data from 2000 to 2010. Our results indicate that the NDVI during the growing season had increased by 0.03% during the 11-year period. Patterns of change in vegetation cover differed among locations, with 58.7% of the study area displaying increased NDVI values, and in 7.3% of the study area, within an ecological restoration zone, the increase was significant. Effective ecological restoration programs, such as Grain for Green and hill closure for afforestation, have improved the environmental conditions. The spatiotemporal variations in vegetation cover were likely to be a synergistic impact of climate change (fluctuations in temperature and precipitation) and human activities. A residual analysis of the changes in the NDVI indicated that human activities had either improved or degraded vegetation cover in some parts of southern China. Specifically, the negative effects of extreme weather events in 2009 and 2010 offset the positive benefits of ecological reconstruction programs in the western part of the study area. This indicates that extreme weather events should be considered in the design and planning of future ecological reconstruction. Drought-resistant plant species might be considered for future ecological projects. However, an eco-risk assessment should be conducted when introducing drought-resistant plant species.
Forest carbon stocks has an important role in the global carbon budget. Based on the satellite-observed and LPJ model simulated aboveground biomass carbon (ABC) data, the spatial and temporal changes ...of subtropical forest carbon storage in the Yangtze River basin and its relations to the climate variation and human activities were analyzed by using the methods of cumulative curve analysis and climate sensitivity analysis during 1993–2012. The results revealed that: (1) In general, the forest ABC increased obviously in the Yangtze River basin during the past 20 years, and the ABC rose from 2563.91 Tg C in 1993 to 2893.17 Tg C in 2012, with a growth rate of 12.84%. The higher ABC distribution was mainly concentrated in the Jialing River basin and Hanjiang River basin and the significantly increasing trends could be found in most area of the Yangtze River basin; (2) The forest ABC was sensitive to the changes of temperature and precipitation. When the temperature increases by 1 °C, the ABC in the Yangtze River basin will increase by 3.32%, while it will decrease by −6.12% when the precipitation increases by 10%; (3) The forest ABC growth rate had accelerated from 3.15% in 1993–2000 to 8.01% in 2001–2012. The cumulative curve of the forest ABC was generally higher than the temperature or the precipitation after 2000. The total areas induced by climate variation and human activities accounted for 30.5% and 52.59% with an increases in ABC by 67.52 Tg C and 188.74 Tg C from 1993 to 2012, respectively. The implementation of major forestry projects might be the main reason for the rapid increase of forest ABC in the Yangtze River basin. This study suggested human activities such as ecological projects might contribute to the accelerated greening trend and highlighted the pivotal role of subtropical forest ABC in the carbon budget in China.
Changing features and trends of annual mean forest satellite-observed ABC (aboveground biomass carbon), LPJ simulated ABCsim (simulated aboveground biomass carbon) and HABC (human-influenced aboveground biomass carbon) in the Yangtze River basin during the period of 1993–2012. Display omitted
•The relative impacts of climate change and human activities on forest ABC were analyzed in the Yangtze River basin.•The forest ABC increased significantly during the past 20 years and the growth rates sped up since 2000.•The forest ABC was sensitive to the changes of temperature and precipitation in the Yangtze River basin.•Major ecological projects were the main cause of the forest restoration in the Yangtze River basin.
This research demonstrates a novel method to communicate in Higher Education and raise awareness of the 2030 Agenda for Sustainable Development and particularly of Sustainable Development Goals, a ...vital step in accelerating action for their fulfillment. Students of the Faculty of Engineering during the “Ecology” course participated in groups in ten Ecological Projects covering a wide range of fields. These creative and experimental Ecological Projects focused on Sustainable Development Goals 3, 4, 6, 7, 12, 13, 14, 15 were inspired by Environmental science and Ecology. Their presentation occurred as event for the World Environment Day and the European Sustainable Development Week in the central square of the capital city of a region, which is a lignite mining region and the country’s energy heart. The Ecological Projects’ overall impacts were investigated through questionnaires completed by the participating students. Various statistical techniques were conducted. Nineteen questions establish as a measurement tool in its final form the questionnaire, whose Cronbach’s alpha is 0.895 indicating that an excellent reliability was estimated. The central tendency of the responses in Questions such as Q2, Q3, Q4, Q5, Q6, Q8, Q10, Q14, Q15, Q16, Q17, Q18, Q19 indicates that Ecological Projects had enough impact on students’ cognitive, social and moral level. The Ecological Projects’ implementation and presentation sufficiently raised awareness of the Sustainable Development Goals. In three questions were detected statistically significant differences between the genders. Finally, according to the questionnaire responses, pairs of questions with moderate or strong monotonic association between them are presented too.
•10 Ecological Projects sufficiently raised awareness of Sustainable Development Goals.•The Projects focused on Sustainable Development Goals 3, 4, 6, 7, 12, 13, 14, 15.•The Cronbach’s alpha is 0.895 indicating that an excellent reliability was estimated.•Such raising awareness activities could be implemented in Higher Education.
•The grazing intensity decreased significantly after starting the ecological projects.•53.7% of grassland NDVImax showed a decreased trend.•NDVImax dynamics were strongly affected by ...drought.•Human-induced degradation only accounted for 4.4% of grasslands.
To alleviate grassland degradation and improve ecosystem functions, the Chinese government has implemented some ecological projects since 2004 across the Tibetan Plateau, such as ‘Return Grazing Land to Grassland Project’ and the ‘Compensation and Rewards to Herders for Natural Grassland Conservation’. Meanwhile, the frequency and intensity of drought events have strengthened in this plateau. However, how grasslands respond to these projects and drought remains controversial. Here, taking the northern Tibetan Plateau (NTP) as the study area, we first quantified the spatiotemporal changes in the annual maximum grassland NDVI (NDVImax) after the implementation of the ecological projects (2005–2015). Then, we assessed the effects of drought (Standardized Precipitation-Evapotranspiration Index, SPEI) and ecological projects on the dynamics of NDVImax. The results showed that (1) the grazing intensity decreased significantly across the NTP after the start of ecological projects, but grassland NDVImax did not increase as expected. Statistically, 53.7% of grasslands showed a decreasing NDVImax, of which 5.7% had a significant decrease (P < 0.05), mainly in the central and eastern NTP. (2) NDVImax positively correlated with SPEI at the pixel, county, and regional scales, suggesting that drought was the driving force for the decreasing NDVImax. The severe and extreme drought events in 2015 contributed to 9.4% and 17.7% reduction of grassland NDVImax, respectively. (3) The residual analysis demonstrated that there were 4.4% of the grasslands experienced human-induced degradation. However, on the whole, the effects of ecological projects on vegetation changes of the NTP were positive. Our findings suggested that the positive effects of the ecological projects on vegetation growth were relatively mitigated or offset by drought. Thus, we question the validity of evaluating the effectiveness of ecological projects only according to the trend of vegetation productivity derived from remote-sensing based vegetation index.
Los investigadores en ecología pretendemos desarrollar proyectos basados en ideas novedosas pero, como todos los seres humanos, tenemos una capacidad de creatividad limitada. Por ende, es común que ...durante nuestra vida académica se nos ocurran sólo unas pocas ideas realmente originales. Entonces, conocer cómo surgen las ideas se torna vital. Si estamos al inicio de la vida académica, nos facilitará el desarrollo de los primeros proyectos independientes, y si estamos hacia el final, puede alargar la etapa creativa de la vida profesional. En este ensayo, primero describiré algunas sugerencias para estimular la generación de proyectos originales en ecología y detallaré el contexto en el cual se gestaron. Finalmente, propondré un marco conceptual integrador cuyo uso puede estimular el surgimiento de ideas originales. En base a experiencias personales que he detallado en el texto, identifico tres aspectos que pueden estimular la creatividad: el inconformismo con las ideas dominantes, la existencia de contratiempos y la atención por lo atípico. Niveles extremos de estos aspectos son contraproducentes. Niveles mínimos de inconformismo, contratiempos o interés por lo atípico atentan contra la creatividad porque estimulan la sumisión intelectual a los paradigmas dominantes, fomentan la comodidad y promueven ceguera antes los detalles por fuera de la norma. Pero niveles muy altos también limitan la creatividad porque estimulan la crítica sin fundamentos, generan estrés permanente y estimulan el detallismo excesivo, descontextualizando un fenómeno de su entorno. En consecuencia, propongo que la generación de ideas originales se ve maximizada con niveles intermedios de inconformismo, contratiempos y atención a lo atípico. Para estimular proyectos en ecología basados en ideas originales sugiero poseer algún nivel de inconformismo sobre las ideas dominantes, considerar a los pequeños contratiempos como oportunidades y prestar atención a lo atípico sin desatender el contexto de donde provienen.
Land degradation has become an urgent environmental issue globally. The complexity of land degradation hinders its quantification and monitoring, which is needed to realize the sustainable ...development of land resources. This study constructed a comprehensive index—land degradation status index (LDSI), which integrates in fractional vegetation cover (FVC), net primary productivity (NPP), albedo, and modified temperature vegetation drought index (MTVDI) based on spatial principal component analysis (SPCA). Land degradation was then identified by the dynamics of land degradation status during 2001–2018. This study investigated the spatio‐temporal process and driving mechanism of land degradation in Northern China. The result indicates that: (1) LDSI had a better monitoring performance compared with normalized difference vegetation index (NDVI), (2) although some degraded land had been effectively rehabilitated (17.11%), a highly clustered spatial distribution of land degradation status remained, challenging to break, (3) localized land degradation had expanded (1.063%), mainly in semiarid (0.481%), dry sub‐humid (0.289%), and humid (0.187%) regions, and (4) differences in climate, environmental backgrounds, and human activities were driven land degradation status and process. This study also assessed the effectiveness of ecological projects implemented by the Chinese government. The in‐depth understanding of the change regularity and influencing mechanism in land degradation status and process can provide a scientific basis for formulating ecological policies based on local conditions.
Greening is recognized to occur in China; however, it is still unclear about the change of vegetation and its attributions from climate change and human activities in Inner Mongolia, located in a ...typical transition climate zone from humid to arid. This study has comprehensively deliberated the variations of the Normalized Difference Vegetation Index (
NDVI
) in 2001–2018 and quantified its controls resulting from climate change and human activities. The results showed that
NDVI
in Inner Mongolia experienced a significant increase with a rate of 0.0018/year (
P
< 0.05) during 2001–2018. Climate change dominated the
NDVI
variations area accounting for 55.43%, while human activities 44.57%. The effects of climate change increased from south to north. The increase in precipitation dominated the augment of
NDVI
in the east and middle of Inner Mongolia. Climate change had slight effects on vegetation in the drier regions due to the counterbalance effect of precipitation and vapor pressure deficit. Moreover, human activities are the chief reasons for the
NDVI
increase in western Inner Mongolia, especially in the arid zone. In general, ecological projects, cropland expansion, urbanization, and human management measures made positive contributions to vegetation growth. Ecological projects among all human activities were the most effective way to affect vegetation growth.
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