Nonlinear characteristics of the vegetation change and its response to climate change in the karst region of southwest China

The vegetation is known to be sensitive to both climate change and anthropogenic disturbance. However, the relationship between changes in vegetation and climate is unclear in karst regions. The nonlinear characteristics of vegetation change and its possible relationships with driving factors in the karst region of southwest China are revealed, using methods of Ensemble Empirical Mode Decomposition, Mann-Kendall, and Partial Least Squares Regression. The results show that: (1) vegetation changes demonstrate an increasing trend with an abrupt change in 2002. Multiple time scales of 3, 6, 10, and 25-year are observed in vegetation variations, dominated by long-term trend and the short time scale of 3-year with variance contributions of 58.10% and 28.63%. (2) The relationship of climate indexes with vegetation changes shows r2 = 0.78 ( p < 0.01) based on the reconstruction of characteristic scales, indicating significant great relationship. In space, the area percentage with relationship of climate to vegetation is more than 50%, and the impact is much greater after the abrupt change of vegetation in 2002 ( r2 are 0.24–0.91 and 0.42–0.99, respectively). In addition, the correlation between vegetation change and ecological engineering is 0.15 ( p < 0.01). The results indicate that climate change is the main impact factor of vegetation change, ecological engineering has positive influences in improving vegetation condition, and methods of scales decomposition and abrupt detection could reveal some hidden information for better understanding ecosystems in karst regions.

Nonlinear Characteristics of NPP Based on Ensemble Empirical Mode Decomposition from 1982 to 2015—A Case Study of Six Coastal Provinces in Southeast China

Monitoring vegetation net primary productivity (NPP) is very important for evaluating ecosystem health. However, the nonlinear characteristics of the vegetation NPP remain unclear in the six provinces along the Maritime Silk Road in China. In this study, using NDVI and meteorological data from 1982 to 2015, NPP was estimated with the Carnegie-Ames-Stanford Approach (CASA) model based on vegetation type dynamics, and its nonlinear characteristics were explored through the ensemble empirical mode decomposition (EEMD) method. The results showed that: (1) The total NPP in the changed vegetation types caused by ecological engineering and urbanization increased but decreased in those caused by agricultural reclamation and vegetation destruction, (2) the vegetation NPP was dominated by interannual variations, mainly in the middle of the study area, while by long-term trends, mainly in the southwest and northeast, (3) for most of the vegetation types, NPP was dominated by the monotonically increasing trend. Although vegetation NPP in the urban land mainly showed a decreasing trend (monotonic decrease and decrease from increase), there were large areas in which NPP increased from decreasing. Although vegetation NPP in the farmland mainly showed increasing trends, there were large areas that faced the risk of NPP decreasing; (4) dynamical changes of vegetation type by agricultural reclamation and vegetation destruction made the NPP trend monotonically decrease in large areas, leading to ecosystem degradation, while those caused by urbanization and ecological engineering mainly made the NPP increase from decreasing, leading to later recovery from early degradation. Our results highlighted the importance of vegetation type dynamics for accurately estimating vegetation NPP, as well as for assessing their impacts, and the importance of nonlinear analysis for deepening our understanding of vegetation NPP changes.

Transplanting Coral Fragments in Close Contact Enhances Their Survival and Growth on Seawalls

Accelerated urbanisation has replaced many natural shorelines with coastal defences, resulting in the loss of natural habitats. However, structures such as seawalls can support some biotic assemblages, albeit of lower species richness. Ecological engineering techniques such as coral transplantation can enhance biodiversity on these artificial structures, but its success is circumscribed by high costs. Little is known about the fusion of discrete coral colonies that could potentially improve coral transplantation success on seawalls, particularly for the slow-growing massive species that are generally well-adapted to living on seawalls. Here, we investigated the feasibility and cost-effectiveness of transplanting Platygyra sinensis on seawalls by comparing the survivability and growth of fragments transplanted adjoining with those transplanted further apart. Fragments (approximately 3 cm diameter; n = 24) derived from three individuals were randomly grouped into two treatments, transplanted at 0.5 cm and 5 cm apart. Fragments in the former treatment came into contact with each other after three months. We observed that in all cases, the contact zones were characterised by a border of raised skeletal ridges without tissue necrosis, often termed nonfusion (=histoincompatible fusion). The adjoining transplants showed better survival (75 vs. 43%) and grew at a rate that was significantly higher than fragments transplanted 5 cm apart (3.7 ± 1.6 vs. 0.6 ± 1.1 cm2 month−1). Our projections demonstrated the possibility of reducing transplantation cost (USD cm−2) by 48.3% through nonfusion. These findings present nonfusion as a possible strategy to increase the overall cost-effectiveness of transplanting slow-growing massive species on seawalls.

Spatial-Temporal Variation Characteristics and Influencing Factors of Vegetation in the Yellow River Basin from 2000 to 2019

Vegetation is a crucial and intuitive index that can be used to evaluate the ecological status. Since the 20th century, land use has changed significantly in Yellow River Basin (YRB), along with great changes of vegetation, serious soil erosion, and gradual ecological deterioration. To improve the ecological environment in the YRB, China has carried out a series of ecological protection projects since the 1970s. Therefore, long-term sequence monitoring of vegetation in YRB is necessary to show the conservation effect and better support the further protection and restoration. This study analysed vegetation changes from 2000 to 2019 based on an annual mean fractional vegetation cover (FVC) dataset. The Theil–Sen median trend analysis method was used to analyse trends in FVC. The results showed that the vegetation in the YRB has improved significantly, with an average annual growth rate of 0.65%, and the ‘green line’ of vegetation has moved approximately 300 km westward. The influence of climate on vegetation is essential; therefore, this study also analysed the influence of temperature and precipitation on vegetation over time and space. Ecological control and afforestation are important anthropogenic factors that affect vegetation. The growth trend (0.6%/a) in key ecological function regions (KEFRs) was the fastest, and even though the protection measures are not strict, they provide space for afforestation. The China Ecological Conservation Red Line (CECRL) and the national nature reserves (NNRs) showed relatively flat trends. Ecological afforestation projects were closely correlated with the growth trend of the FVC. The correlation between FVC and the intensity of ecological engineering was significant in typical areas.

Wooden Extra Stories in Concrete Block of Flats in Finland as an Ecologically Sensitive Engineering Solution

This chapter examined the various stages and benefits of wooden extra stories from the perspective of Finnish housing and real estate companies through interviews with professionals involved in these projects. Key findings highlighted are as follows: (1) in the feasibility study, project planning primarily focuses on property condition and potential improvement targets as well as other considerations, for example, compliance with current regulations and parking arrangements; (2) in the project planning, application of extra stories is thoroughly examined, and construction costs, profits, and the sale of building rights are discussed; (3) in implementation planning, issues related to building rights, city plan change, and conditions of the company that manages the property play an important role; and (4) during construction, frequent information updates are made to residents regarding the site arrangements and the construction program. Wooden extra floor construction, which requires commitment, investment, and cooperation among the interested parties, has great potential in construction technology, contracting mechanisms, and ecological engineering solutions. It is believed that this chapter will increase the dissemination of wooden extra stories, thus contributing to the greater use of more sustainable materials in renovation projects and the ecologically sensitive engineering approaches to meet the challenges arising from climate change.

Retrospection of Outbreaks of Spodoptera mauritia Boisduval in NER India: The Solution Lies in Ecological Engineering, Not in Insecticides

Rice cultivation in North East India is organic by tradition; however, the recent outbreaks of the rice-swarming caterpillar, Spodoptera mauritia Boisduval, have compelled rice-farmers to use synthetic insecticides. The outbreak in 2016 affected more than 56,768 ha of winter rice in 28 districts of Assam. About 25,545–42,576 L insecticide was applied in the state to combat the outbreak. This is one of the highest insecticide loads ever to be added to the rice ecosystem of Assam. Such a load, if added repeatedly with the reoccurrence of outbreaks, may affect the innate resilience of the rice ecosystem in the long run. In this paper, the outbreak of RSC has been analysed from an ecological perspective in order to replace the existing policy of exclusive dependence on insecticide. The review will help the researchers, extension workers and policy makers of the rice producing countries, more specifically in Asian countries, which together account for more than 91% of the world’s rice production.