Search Results (6)

Mangrove forests are among the most productive vascular plants on Earth. The gross (GPP) and aboveground forest net primary production (ANPP) correlate positively with precipitation. ANPP also correlates inversely with porewater salinity. The main drivers of the forest primary production are the porewater salinity, rainfall, tidal inundation frequency, light intensity, humidity, species age and composition, temperature, nutrient availability, disturbance history, and geomorphological setting. Wood production correlates positively with temperature and rainfall, with rates comparable to tropical humid forests. Litterfall accounts for 55% of the NPP which is greater than previous estimates. The fine root production is highest in deltas and estuaries and lowest in carbonate and open-ocean settings. The GPP and NPP exhibit large methodological and regional differences, but mangroves are several times more productive than other coastal blue carbon habitats, excluding macroalgal beds. Mangroves contribute 4 to 28% of coastal blue carbon fluxes. The mean and median canopy respiration equate to 1.7 and 2.7 g C m⁻² d⁻¹, respectively, which is higher than previous estimates. Mangrove ecosystem carbon fluxes are currently in balance. However, the global mangrove GPP has increased from 2001 to 2020 and is forecast to continue increasing to at least 2100 due to the strong fertilization effect of rising atmospheric CO₂ concentrations. Full article

As media consumption through electronic devices increases, there is growing interest in ASMR videos, known for inducing relaxation and positive emotional states. However, the effectiveness of ASMR varies depending on each video’s characteristics. This study identifies key sound and image features that evoke specific emotional responses. ASMR videos were categorized into two groups: high valence–low relaxation (HVLR) and low valence–high relaxation (LVHR). Subjective evaluations, along with physiological data such as electroencephalography (EEG) and heart rate variability (HRV), were collected from 31 participants to provide objective evidence of emotional and physiological responses. The results showed that both HVLR and LVHR videos can induce relaxation and positive emotions, but the intensity varies depending on the video’s characteristics. LVHR videos have sound frequencies between 50 and 500 Hz, brightness levels of 20 to 30%, and a higher ratio of green to blue. These videos led to 45% greater delta wave activity in the frontal lobe and a tenfold increase in HF HRV, indicating stronger relaxation. HVLR videos feature sound frequencies ranging from 500 to 10,000 Hz, brightness levels of 60 to 70%, and a higher ratio of yellow to green. These videos resulted in 1.2 times higher beta wave activity in the frontal lobe and an increase in LF HRV, indicating greater cognitive engagement and positive arousal. Participants’ subjective reports were consistent with these physiological responses, with LVHR videos evoking feelings of calmness and HVLR videos inducing more vibrant emotions. These findings provide a foundation for creating ASMR content with specific emotional outcomes and offer a framework for researchers to achieve consistent results. By defining sound and image characteristics along with emotional keywords, this study provides practical guidance for content creators and enhances user understanding of ASMR videos. Full article

Tree-ring blue intensity (BI) has the potential to provide information on past summer temperatures of a similar quality to that of tree-ring maximum latewood density and at a substantially reduced cost. To explore the applicability of BI in subtropical regions, the inverted BI for the earlywood, latewood, and the delta BI (DBI) parameters, together with tree-ring width of subalpine fir (Abies fargesii Franch.) in the Shennongjia area of China, were measured, and the corresponding chronologies were developed. The relationships between these chronologies and monthly precipitation, monthly mean minimum temperature, monthly mean temperature, and monthly mean maximum temperature were explored through correlation analysis. Results show that the DBI chronology is closely related to the temperature in August of the current year, indicating that BI, specifically delta BI, data are suitable for use in dendroclimatology studies in subtropical areas. The resultant mean temperature reconstruction for August, based on DBI, explains 40.8% of the temperature variance and is robustly validated using independent periods from the calibration. This pilot study not only highlights the potential of DBI for temperature reconstruction in China but also offers valuable insights into historical climate variations in the Shennongjia region. Moreover, it shows the potential for utilizing such tree-ring data from low-latitude regions to derive past climate data in subtropical warm-humid zones. Full article

Tree-ring blue intensity (BI) has been widely applied for temperature reconstructions in many regions around the globe. However, it remains untested in the southeastern Tibetan Plateau (TP) where a large number of ancient trees are distributed. In this study, we developed earlywood blue intensity (EWBI), latewood blue intensity (LWBI), and delta blue intensity (ΔBI) chronologies based on tree-ring samples collected from Abies spectabilis at two sites in the southeastern TP. Our results reveal that the EWBI and ΔBI chronologies correlated negatively with temperature parameters and LWBI chronology correlated positively with temperature parameters, respectively. Among them, the LWBI chronology was identified most suitable for reconstructing the mean temperature in August. A linear regression model was developed for the August temperature reconstruction, which accounts for 34.31% of the observed variance in the period of 1954–2017. The reconstruction, spanning 1789–2017, is highly consistent with other tree-rings based temperature reconstructions from the neighboring regions. Our findings reveal a potential linkage between the August temperature anomaly in the southeastern TP and the Atlantic Multidecadal Oscillation (AMO), which suggests that the AMO fingerprint in the region is not just evident in winter but also in summer. Full article

The resin tapping of pine trees in Poland ended in the early 1990s. However, we can still find individual trees, and sometimes larger groups of trees, that were tapped. This study focused on the effect of the mechanical wounding of trees during resin tapping on the growth and climatic sensitivity of pine trees. The study concerned a 160-year-old pine stand in northwestern Poland in which resin tapping was last performed in the 1970s. All the trees had remained standing because of their high quality, which had destined them for seed collection. The stand included both resin-tapped (RT) and non-RT (NRT) trees. Our study was based on a dendrochronological analysis of two signals—annual tree ring widths (TRWs) and their delta blue intensity (DBI). We observed a significant increase in annual TRW after resin tapping had ceased, alongside a decrease in the DBI. The temporal stability in growth response was examined using daily climatic correlations from 1921 to 2021. It was found that the climatic sensitivity of RT and NRT pines was similar. There were differences in only some of the years, most while resin tapping was occurring, and then approximately 20 years after the resin tapping had ceased. However, these were small differences that mainly related to the strength of the correlation. It was also discovered that we can obtain different types of information from the study of TRWs and DBI. Full article

Suaeda salsa (L.) Pall. (S. salsa) acts as a pioneer species in coastal wetlands due to its high salt tolerance. It has significant biodiversity maintenance, socioeconomic values (e.g., tourism) due to its vibrant color, and carbon sequestration (blue carbon). Bohai Bay region, the mainly distributed area of S. salsa, is an economic intensive region with the largest economic aggregate and population in northern China. The coastal wetland is one of the most vulnerable ecosystems with the urbanization and economic developments. S. salsa in Bohai Bay has been changed significantly due to several threats to its habitat in past decades. In this paper, we analyzed all available archived Landsat TM/ETM+/OLI images of the Bohai Bay region by using a decision tree algorithm method based on the Google Earth Engine (GEE) platform to generate annual maps of S. salsa from 1990 to 2020 at a 30-m spatial resolution. The temporal-spatial dynamic changes in S. salsa were studied by landscape metric analysis. The influencing factors of S. salsa changes were analyzed based on principal component analysis (PCA) and a logistic regression model (LRM). The results showed that S. salsa was mainly distributed in three regions: the Liao River Delta (Liaoning Province), Yellow River Delta (Shandong Province), and Hai River Estuary (Hebei Province, Tianjin). During the past 31 years, the total area of S. salsa has dramatically decreased from 692.93 km² to 51.04 km², which means that 92.63% of the area of S. salsa in the Bohai Bay region was lost. In the 641.89 km² area of S. salsa that was lost, 348.80 km² of this area was converted to other anthropic land use categories, while 293.09 km² was degraded to bare land. The landscape fragmentation of S. salsa has gradually intensified since 1990. National Nature Reserves have played an important role in the restoration of suitable S. salsa habitats. The analysis results for the natural influencing factors indicated that precipitation, temperature, elevation, and distance to the coastline were considered to be the major influencing factors for S. salsa changes. The results are valuable for monitoring the dynamic changes of S. salsa and can be used as effective factors for the restoration of S. salsa in coastal wetlands. Full article