Chlorophyll a (Chl a), chlorophyll b (Chl b), chlorophyll (a+b) and net photosynthetic rate (Pn) of <i>Sorghum bicolor</i> (L.) Moench seedlings under various salt and alkali stresses.

Chlorophyll a (Chl a), chlorophyll b (Chl b), chlorophyll (a+b) and net photosynthetic rate (Pn) of Sorghum bicolor (L.) Moench seedlings under various salt and alkali stresses.</p

Response of proline and soluble protein content of sorghum to saline-alkali stress.

(A)Proline content. (B) Soluble protein content. Note: Values represent means±S.E. Values at each treatment group followed by different letters are significantly different (P < 0.05).</p

Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), malondialdehyde (MDA) content of <i>Sorghum bicolor</i> (L.) Moench seedlings under various salt and alkali stresses.

Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), malondialdehyde (MDA) content of Sorghum bicolor (L.) Moench seedlings under various salt and alkali stresses.</p

Plant height, the maximum leave areas, root length, biomass and relative growth rate (RGR) of <i>Sorghum bicolor</i> (L.) Moench seedlings under various salt and alkali stresses.

Plant height, the maximum leave areas, root length, biomass and relative growth rate (RGR) of Sorghum bicolor (L.) Moench seedlings under various salt and alkali stresses.</p

Two-way ANOVA of effects of salinity (S), alkalinity (A), and their interactions on growth, physiological index organic solutes, inorganic cations and anions of <i>Sorghum bicolor</i> (L.) Moench seedlings.

Two-way ANOVA of effects of salinity (S), alkalinity (A), and their interactions on growth, physiological index organic solutes, inorganic cations and anions of Sorghum bicolor (L.) Moench seedlings.</p

Response of the persentation of dry biomass of sorghum to saline-alkali stress.

Note: Values represent means±S.E. Values at each treatment group followed by different letters are significantly different (P < 0.05).</p

Response of inorganic cations and anions of sorghum seedlings to saline-alkali stress.

(A)Na+ content. (B) K+ content. (C) Mg2+ content. (D) Ca2+ content. (E) SO42-content. (F) Cl-content. Note: Values represent means±S.E. Values at each treatment group followed by different letters are significantly different (P < 0.05).</p

Table_1_Comparing the Effectiveness of Biodiversity Conservation Across Different Regions by Considering Human Efforts.DOCX

The effective allocation of funds is of significant importance for biodiversity conservation, but there is currently no scientific method for comparing the effectiveness of biodiversity conservation across different regions. Existing studies omit differences in the ecological background, such as the terrain, climate, hydrology, soil, and ecosystem, or do not differentiate between the impacts caused by humans and nature. To address these limitations, we take habitat quality as a proxy for biodiversity and quantify the human-induced habitat quality changes as a means of measuring the efforts of management departments, with the background differences eliminated using a reference condition index. The method is applied to the San Jiang Plain Wetlands and Northwest Tibet Qiang Tang Plateau Biodiversity National Key Ecological Function Region in China. The results show that the effects of human activities on habitat improvement or degradation are overestimated or underestimated if there is no differentiation between human and natural causes. Human-induced habitat quality changes broadly reflect the human efforts toward biodiversity conservation. By considering the human efforts and background differentiation, the proposed method allows the effectiveness of biodiversity conservation to be compared across different regions. This study provides a scientific reference for China’s transfer payment policy and for the biodiversity funds allocated in other countries. Furthermore, our results will guide the practice of improving habitat quality and biodiversity.</p

Additional file 1 of Effects of shell sand burial on seedling emergence, growth and stoichiometry of Periploca sepium Bunge

Additional file 1: Fig. S1. Effects of different burial depths on the first emergence time of P. sepium. Different letters denote significant differences at P < 0.05

Data_Sheet_1_Effect of Wetland Restoration and Degradation on Nutrient Trade-Off of Carex schmidtii.docx

Plant nutrient trade-off, a growth strategy, regulates nutrient stoichiometry, allocation and stoichiometric relationships, which is essential in revealing the stoichiometric mechanism of wetland plants under environmental fluctuations. Nonetheless, how wetland restoration and degradation affect nutrient trade-off of wetland plants was still unclear. In this study, field experiments were conducted to explore the dynamic of nutrient stoichiometry and nutrient limitation of Carex schmidtii under wetland restoration and degradation. Plant nutrient stoichiometry and stoichiometric relationships among natural (NW), restored (RW), and degraded (DW) tussock wetlands were examined. Results showed that nutrient stoichiometry of C. schmidtii was partly affected by wetland restoration and degradation, and growth stages. The N:P and N:K ratios indicated N-limitation for the growth of C. schmidtii. Robust stoichiometric scaling relationships were quantified between some plant nutrient concentrations and their ratios of C. schmidtii. Some N- and P-related scaling exponents are varied among NW, RW, and DW. PCA indicated that wetland restoration and degradation had significantly affected on the nutrient trade-offs of C. schmidtii (May∼August). Compared to NW, nutrient trade-off in RW was more similar to DW. Carex schmidtii had significant correlation between most nutrients and their ratios, and the SEM indicated that plant P and K concentrations had a high proportional contribution to plant C and N concentrations. Insights into these aspects are expected to contribute to a better understanding of nutrient trade-off of C. schmidtii under wetland restoration and degradation, providing invaluable information for the protection of C. schmidtii tussock wetlands.</p