The Sustainable Role of the Tree in Environmental Protection Technologies

The area occupied by Pinus pinaster in Portugal is rapidly diminishing because of forest fires. Ectomycorrhizal fungi form obligate, mutually beneficial associations with P. pinaster which improve plant growth and resistance to adverse conditions. The aim of this work was to assess whether native ectomycorrhizal fungi could be a useful tool in the reforestation of burned areas. The work was conducted in a forest nursery greenhouse, where P. pinaster seedlings were inoculated with compatible ectomycorrhizal fungal isolates: Suillus bovinus, Pisolithus tinctorius, Rhizopogon roseolus, and a mixture of the three fungi, using burned and unburned forest soil as substrate. Inoculation significantly enhanced the growth of P. pinaster, with R. roseolus proving to be the most effective in burned soil, with an 8-fold increase in plant fresh weight. Overall, inoculation stimulated growth most in burned than in unburned soil. This study suggests that inoculation with selected ectomycorrhizal fungi in containerised nurseries can be an advantageous approach for the successful establishment of P. pinaster in burned soil. The obtained results point out to the interest of extending these studies into fire-impacted areas, using ectomycorrhizal fungi as a biological tool.

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Reforestation of burned stands: The effect of ectomycorrhizal fungi on Pinus pinaster establishment

After nearly 20 years of exploration, various areas of the seafloor with hydrocarbon seepage have been discovered in the South China Sea (SCS). Through linking subsurface and seafloor biospheres, seeps have become natural laboratories to enhance our knowledge on the processes of hydrocarbon migration and associated hydrocarbon-based ecosystems in the marine environment. This review summarizes the distribution of macrofauna in the active seep areas of the SCS and describes the physiological characteristics of three groups of representative macrofauna (bathymodioline mussels, pliocardiine clams, siboglinid tubeworms). In addition, a comparison is made between the seep macrofauna of the SCS and the Northwest Pacific Ocean. Modes of energy transfer and microbial processes are elucidated by integrating trace element, stable isotope, and lipid biomarker data of macrofaunal soft tissues. Our aims are to provide an overview of the macro-ecology of the SCS seeps and to underscore aspects which desire more research efforts in the future. 

Macro-ecology of cold seeps in the South China Sea

Field spectroscopy has been suggested to be an efficient method for predicting soil properties using quantitative mathematical models in a rapid and non-destructive manner. Traditional multivariate regression algorithms usually regard the modeling of each soil property as a single task, which means only one response variable is considered as the output during modeling. Therefore, these algorithms are less suitable for the prediction of several key soil properties with low concentrations or unobvious spectral absorption signals. In the current study, we investigated the performance of a linear multi-task learning (LMTL) algorithm based on a regularized dirty model for modeling and predicting several key soil properties using field spectroscopy (350–2500 nm) as an integrated approach. We tested seven key soil properties including available nitrogen (N), phosphorus (P) and potassium (K), pH, water content (WC), organic matter (OM), and electrical conductivity (EC) in drylands. The model performances of LMTL models were compared with the commonly used single-task algorithm of the partial least squares regression (PLS-R). Our results show that the LMTL models outperformed the PLS-R models with the advantage of shared features; the ratio of performance to deviation (RPD) values in the validation set improved by 10.24%, 4.93%, 25.77%, 11.76%, 6.74%, 53.13%, and 3.15% for N, P, K, pH, WC, OM, and EC, respectively. The best prediction was obtained for OM with RPD = 2.29, indicating high accuracy (RPD > 2). The prediction results of N, P, WC, and pH were categorized as of moderate accuracy (1.4 < RPD < 2), while K and EC were categorized as of poor accuracy (RPD < 1.4). However, the explanatory power of the LMTL models was moderate due to fewer features being selected by the regularization algorithm of the LMTL approach, which should be further studied in the soil spectral analysis. Our results highlight the use of LMTL in field spectroscopy analysis that can improve the generalization performance of regression models for predicting soil properties.

Linear Multi-Task Learning for Predicting Soil Properties Using Field Spectroscopy

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The effect of fire on the vegetation and soil properties of ungrazed shortgrasssteppe rangeland of the Eastern Anatolia region of Turkey

Effects of fire disturbance on the soil physical and chemical properties and vegetation of Pinus massoniana forest in south subtropical area

The macrofaunal community in the Haima cold seeps of the South China Sea was investigated, and trophic relationships were evaluated using carbon and nitrogen stable isotope signatures (δ13C and δ15N). A total of 30 macrofaunal species were identified in this study, most of which were collected from the Gigantidas haimaensis mussel beds. Only four macrofaunal species were collected from the Calyptogena marissinica clam beds, where the environment may not be suitable for the survival of most macrofauna. The bush of slim tubeworms (Sclerolinum sp.) might be an important nursery ground for mussels. G. haimaensis was the predominant species, and its average δ13C and δ15N values were −52.7‰ and 0.6‰, respectively. Compared with the stable isotope signatures of particulate organic matter (POM), it suggested that the food source of macrofauna in the Haima cold seeps was mainly originated from chemosynthetic autotrophs. In the mussel bed, most of the macrofauna had a large δ13C isotopic distance compared with G. haimaensis, suggesting that G. haimaensis was not a direct food source for most cold-seep macrofauna in the mussel bed. The variation in stable isotope signatures of macrofauna might be attributed to different proportions of methanotrophic and thiotrophic endosymbionts. Neolithodes brodiei and Bathynomus jamesi showed the highest δ13C and δ15N values. However, the large isotopic distance indicated that N. brodiei and B. jamesi might just occasionally visit the cold-seep ecosystem and their food sources were mainly from the upper ecosystem relying on photosynthesis. Overall, our results suggested that there was no significant predator-prey relationship among these macrofaunal species in the Haima cold seeps. This study provided important baseline data of stable isotope signatures for further studies to elucidate the trophic interaction among seep organisms. 

A preliminary study of macrofaunal communities and their carbon and nitrogen stable isotopes in the Haima cold seeps, South China Sea

A method for batch preparation of fucoxanthin from brown algae was established, which possessed the advantages of high yield and high purity. The ultrasonic-assisted extraction method was used to obtain a crude extract from Sargassum fusiforme as the separation sample. Then the crude extract was separated by elution-extrusion countercurrent chromatography. The optimum preparation conditions of fucoxanthin were determined as follows: n-hexane-ethanol-water (20:9:11, v:v:v) as a two-phase solvent system, the mobile phase flow rate was 5 mL min−1, the revolution speed was 800 r min−1, the loading capacity was 60 mg 10 mL−1 and the temperature was 25 °C. By this method, 12.8 mg fucoxanthin with a purity of 94.72% was obtained from the crude extract of Sargassum fusiforme. In addition, when the loading capacity was 50 mg 10 mL−1, the purity of fucoxanthin reached 96.01%. Two types of by-products, chlorophyll and pheophytin, could also be obtained during the process of separation. This optimal method was further applied to separate fucoxanthin from Laminaria japonica and Undaria pinnatifida, and 6.0 mg and 9.7 mg fucoxanthin with a purity of 96.24% and 92.62% were acquired, respectively. Therefore, it was demonstrated that the preparation method of fucoxanthin established in this study had an applicability to brown algae, which improved the utilization value of raw materials.

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One-Step Preparative Separation of Fucoxanthin from Three Edible Brown Algae by Elution-Extrusion Countercurrent Chromatography

Alzheimer’s disease (AD), a neurodegenerative disease, is one of the most intractable illnesses which affects the elderly. Clinically manifested as various impairments in memory, language, cognition, visuospatial skills, executive function, etc., the symptoms gradually aggravated over time. The drugs currently used clinically can slow down the deterioration of AD and relieve symptoms but cannot completely cure them. The drugs are mainly acetylcholinesterase inhibitors (AChEI) and non-competitive N-methyl-D-aspartate receptor (NDMAR) antagonists. The pathogenesis of AD is inconclusive, but it is often associated with the expression of beta-amyloid. Abnormal deposition of amyloid and hyperphosphorylation of tau protein in the brain have been key targets for past, current, and future drug development for the disease. At present, researchers are paying more and more attention to excavate natural compounds which can be effective against Alzheimer’s disease and other neurodegenerative pathologies. Marine natural products have been demonstrated to be the most prospective candidates of these compounds, and some have presented significant neuroprotection functions. Consequently, we intend to describe the potential effect of bioactive compounds derived from marine organisms, including polysaccharides, carotenoids, polyphenols, sterols and alkaloids as drug candidates, to further discover novel and efficacious drug compounds which are effective against AD.

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Application of Marine Natural Products against Alzheimer’s Disease: Past, Present and Future

The spatial and seasonal distributions of stable carbon and nitrogen isotopes (δ13C and δ15N) in dominant zooplankton groups were investigated in Jiaozhou Bay. Zooplankton δ13C values ranged from −22.89‰ to −15.86‰, and δ15N values ranged from 3.18‰ to 13.57‰, respectively. The δ13C and δ15N values generally followed the order of small zooplankton < large calanoids < small Sagitta < large Sagitta. Spatial distribution patterns of zooplankton δ13C and δ15N values varied in different seasons. Our results suggested that the spatial variation of δ13C was mainly controlled by terrigenous organic matter (OM) input and phytoplankton biomass, but water temperature may have played a key role in the seasonal variation of δ13C. In spring, the high phytoplankton biomass might increase the δ13C value of small zooplankton in the inner bay. During other seasons, the δ13C values of zooplankton generally increased from the inner bay to the outer bay, which might be associated with the influence of 13C-depleted terrigenous OM carried by the river discharge. Small zooplankton stable isotope values were significantly correlated with that of particulate organic matter (POM). The influence of anthropogenic nutrient input on isotopic baseline can be cascaded to the zooplankton, and the effect might be weak at higher trophic levels. The Bayesian standard ellipse areas of dominant zooplankton groups were generally smallest in the winter, suggesting a narrow niche width during that time. The niche partition between small zooplankton, large calanoids, and Sagitta was most distinct in winter, and followed by summer. The relative trophic level of Sagitta ranged from 2.23 to 4.01, which generally declined from the inner bay to the outer bay during the spring, autumn, and winter seasons. High anthropogenic nutrient loading might reduce the difference in trophic niches among zooplankton groups. This study provided detailed information on the distribution of zooplankton δ13C and δ15N in a coastal bay, which will be useful for understanding the anthropogenic influence on the ecosystem structure and function.

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Danting Chen

Papers

Effects of fire disturbance on the soil physical and chemical properties and vegetation of Pinus massoniana forest in south subtropical area

A preliminary study of macrofaunal communities and their carbon and nitrogen stable isotopes in the Haima cold seeps, South China Sea

One-Step Preparative Separation of Fucoxanthin from Three Edible Brown Algae by Elution-Extrusion Countercurrent Chromatography

Application of Marine Natural Products against Alzheimer’s Disease: Past, Present and Future

Spatial and Seasonal Variations in the Stable Isotope Values and Trophic Positions of Dominant Zooplankton Groups in Jiaozhou Bay, China