The ongoing climate change‐induced shifts in flowering phenology have emerged as a consequential force impacting biodiversity and ecosystems. Despite the globally recognized significance of flowering ...phenology as a key reproductive attribute, studies in subtropical regions have been relatively fewer, particularly in comparison to temperate and cold regions. Additionally, the nuanced response of deciduous and evergreen plants to climate change remains insufficiently explored. In addressing this gap, we built a phenological model and a generalized linear mixed effect model to assess the differential responses of key flowering phenological traits, that is, first flowering date (FFD), peak flowering date (PFD), end of flowering date (EFD), and flowering duration (FD), to climate factors (temperature and precipitation) between deciduous and evergreen plants. We observed distinct responses in flowering phenological traits to climate change between deciduous and evergreen plants. Specifically, the advancement of FFD, PFD, and EFD in deciduous in response to temperature rise exceeded that in evergreen plants. FD in evergreen plants exhibited a stronger extension to temperature increase compared to deciduous. Conversely, the phenological change of evergreen plants in response to decreasing precipitation was greater than that of deciduous ones. Since temperature is a decisive climatic factor in affecting phenological changes, climate change‐induced advances in flowering phenology of deciduous plants are still larger than evergreen plants. Projections from our phenological model under future climate scenarios (SSP 1‐2.6 and SSP 5‐8.5) indicate a continuous enlargement of difference in flowering phenology between deciduous and evergreen plants, with this trend escalating into the future (2100>2070>2050>2030). The larger extension in FD of evergreens to climate change suggests a potential increase in their proportion within subtropical forest communities relative to deciduous plants. These insights contribute significantly to our understanding of the intricate dynamics of climate‐induced changes in subtropical plant ecosystems.
抽象的
气候变化引起的植物物候改变已对全球范围内生物多样性和生态系统产生重大影响。作为一种重要的生殖性状，开花物候研究主要集中在温带和寒冷地区，亚热带地区的研究较为少见。落叶植物和常绿植物是亚热带两种植物类型，但我们并不清楚它们开花物候对气候变化的响应会有所不同。为此，本文利用中国物候观测网的数据，建立了物候模型和广义线性混合效应模型，评估了落叶和常绿植物的4种开花物候性状，即首次开花日期 (first flowering date/FFD)、开花峰值日期 (peak flowering date /PFD)、开花结束日期 (end of flowering date /EFD)和开花持续时间 (flowering duration /FD)，对两种气候因子(温度和降水)变化的不同响应。结果发现，落叶植物和常绿植物的开花物候对气候变化响应有明显差别。其中，落叶植物的FFD、PFD和EFD对气温升高的敏感性高于常绿植物。但是，与落叶植物相比，常绿植物的FD对增温呈现出更强的延长趋势。相反，常绿植物的物候变化对降水减少的敏感性高于落叶植物；由于温度是驱动亚热带植物开花物候变化的决定性气候因子，它对降水作用的不等比抵消使得气候变化对落叶植物开花物候的影响远高于常绿植物；在SSP 1‐2.6和SSP 5‐8.5两种未来气候情景下，气候驱动的物候模型预测表明，落叶植物和常绿植物的开花物候差异将在未来持续扩大，并逐年呈上升趋势 (2100>2070>2050>2030年)；气候变化引起常绿植物FD的延长大于落叶植物，表明前者由于繁殖适合度增加，其在亚热带森林群落中的比例在未来可能不断扩大。本文研究首次揭示了气候变化对常绿和落叶植物物候差异化影响的机制。研究结果有助于了解和预测亚热带森林生态系统未来的复杂动态过程。
The ongoing climate change‐induced shifts in flowering phenology have emerged as a consequential force impacting biodiversity and ecosystems. We explore the differentiated response of flowering phenology to climate change between evergreen and deciduous species. Our results found that temperature is a key influencing factor of phenological change. Deciduous plants show more shift of flowering phenology than evergreens due to climate change, but reproductive advantages showed the opposite pattern. We predict that evergreen species will gain more competitive advantages in future subtropical forest communities.
As an interesting and important trait of some drought-tolerant species, heteromorphic leaves are distributed differentially along plant vertical heights. However, the underpinning mechanism for the ...formation of heteromorphic leaves remains unclear. We hypothesize that heteromorphic leaves are caused by the hydraulic constraints possibly due to the compensation of the changes in functional traits in response to water transport capacity or the reduction of ineffective water loss. In this study, differences in water transport capacity, morphological traits, anatomical structures, and cellular water relations among three typical types of heteromorphic leaves (i.e., lanceolate, ovate, and broad-ovate) of
Populus euphratica
Oliv. (a dominant species of desert riparian forest in Central and West Asia) and their relationships were analyzed in order to explore the forming mechanism of heteromorphic leaves. The results showed that the lanceolate, ovate, and broad-ovate leaves were growing in the lower, intermediate, and higher positions from the ground, respectively. Morphological traits, anatomical structures, cellular water relations, and water transport capacity significantly varied among the three types of heteromorphic leaves (
P
< 0.01). Drought stress in broad-ovate leaves was significantly higher than that in ovate and lanceolate leaves (
P
< 0.01). Water transport capacity has significant correlations with morphological traits, anatomical structures, and cellular water relations (
R
2
≥ 0.30;
P
< 0.01). Our results indicated that heteromorphic leaves were used as an important adaptive strategy for
P. euphratica
to alleviate the increase of hydraulic constraints along vertical heights.
A high resolution record of sea-ice concentration on the North Icelandic shelf during the last millennium has been reconstructed using a diatom-based sea-ice transfer function. The reconstructed ...sea-ice record for the top of sediment core MD99-2275 ex- hibits a slightly increasing trend over the last 1000 years. Prior to AD 1300 sea-ice abundance was generally below the mean value, suggesting the strong influence of warm waters from the Irminger Current during the Medieval Warm Period. A marked increase of sea-ice concentration indicates an abrupt change to colder conditions after AD 1300, corresponding to the onset of the Little Ice Age. The agreement between the reconstructed sea-ice concentration and IP25 data obtained from the same core, as well as with historical records of Icelandic sea ice, suggests that diatoms may provide a valuable tool for future quantitative reconstructions of past sea-ice variability. In addition, agreement between changes in the reconstructed sea-ice record and vari- ations in the abundance of the major diatom components indicates that sea-ice conditions on the North Icelandic shelf are gen- erally strongly influenced by changes in the strength of two different water masses, the cold Polar water periodically derived from the East Greenland Current and the warm Irminger Current derived from the North Atlantic Current. Our proxy evidence also indicates that variations in solar activity have a considerable impact on ocean dynamics, which in turn affects sea-ice abundance.
In the present study, a highly stable luteinizing-hormone-releasing hormone (LHRH)-conjugated PEGylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles were developed for the successful treatment ...of prostate cancers. We have demonstrated that a unique combination of targeted drug delivery and controlled drug release is effective against prostate cancer therapy. The docetaxel (DTX)/PLGA-LHRH micelles possessed a uniform spherical shape with an average diameter of ~170 nm. The micelles exhibited a controlled drug release for up to 96 h which can minimize the non-specific systemic spread of toxic drugs during circulation while maximizing the efficiency of tumor-targeted drug delivery. The LHRH-conjugated micelles showed enhanced cellular uptake and exhibited significantly higher cytotoxicity against LNCaP cancer cells. We have showed that PLGA-LHRH induced greater caspase-3 activity indicating its superior apoptosis potential. Consistently, LHRH-conjugated micelles induced threefold and twofold higher G2/M phase arrest than compared to free DTX or PLGA NP-treated groups. Overall, results indicate that use of LHRH-conjugated nanocarriers may potentially be an effective nanocarrier to effectively treat prostate cancer.
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