Mathilde Millan, Alexis Bonnet, Jean Dauzat, Rémi Vezy
Background and aims: Lidar is a promising tool for fast and accurate measurements of trees. There are several approaches to estimate above-ground woody biomass using lidar point clouds. One of the most widely used methods involves fitting geometric primitives (e.g. cylinders) to the point cloud, thereby reconstructing both the geometry and topology of the tree. However, current algorithms are not suited for accurate estimation of the volume of finer branches, because of the unreliable point dispersions from, for example, beam footprint compared to the structure diameter.
Method: We propose a new method that couples point cloud-based skeletonization and multi-linear statistical modelling based on structural data to make a model (structural model) that accurately estimates the above-ground woody biomass of trees from high-quality lidar point clouds, including finer branches. The structural model was tested at segment, axis and branch level, and compared to a cylinder fitting algorithm and to the pipe model theory.
Key results: The model accurately predicted the biomass with 1.6 % normalized root mean square error (nRMSE) at the segment scale from a k-fold cross-validation. It also gave satisfactory results when scaled up to the branch level with a significantly lower error (13 % nRMSE) and bias (-5 %) compared to conventional cylinder fitting to the point cloud (nRMSE: 92 %, bias: 82 %), or using the pipe model theory (nRMSE: 31 %, bias: -27 %). The model was then applied to the whole-tree scale and showed that the sampled trees had more than 1.7 km of structures on average and that 96 % of that length was coming from the twigs (i.e. <5 cm diameter). Our results showed that neglecting twigs can lead to a significant underestimation of tree above-ground woody biomass (-21 %).
Conclusions: The structural model approach is an effective method that allows a more accurate estimation of the volumes of smaller branches from lidar point clouds. This method is versatile but requires manual measurements on branches for calibration. Nevertheless, once the model is calibrated, it can provide unbiased and large-scale estimations of tree structure volumes, making it an excellent choice for accurate 3D reconstruction of trees and estimating standing biomass.
{"title":"Advancing fine branch biomass estimation with lidar and structural models.","authors":"Mathilde Millan, Alexis Bonnet, Jean Dauzat, Rémi Vezy","doi":"10.1093/aob/mcae083","DOIUrl":"10.1093/aob/mcae083","url":null,"abstract":"<p><strong>Background and aims: </strong>Lidar is a promising tool for fast and accurate measurements of trees. There are several approaches to estimate above-ground woody biomass using lidar point clouds. One of the most widely used methods involves fitting geometric primitives (e.g. cylinders) to the point cloud, thereby reconstructing both the geometry and topology of the tree. However, current algorithms are not suited for accurate estimation of the volume of finer branches, because of the unreliable point dispersions from, for example, beam footprint compared to the structure diameter.</p><p><strong>Method: </strong>We propose a new method that couples point cloud-based skeletonization and multi-linear statistical modelling based on structural data to make a model (structural model) that accurately estimates the above-ground woody biomass of trees from high-quality lidar point clouds, including finer branches. The structural model was tested at segment, axis and branch level, and compared to a cylinder fitting algorithm and to the pipe model theory.</p><p><strong>Key results: </strong>The model accurately predicted the biomass with 1.6 % normalized root mean square error (nRMSE) at the segment scale from a k-fold cross-validation. It also gave satisfactory results when scaled up to the branch level with a significantly lower error (13 % nRMSE) and bias (-5 %) compared to conventional cylinder fitting to the point cloud (nRMSE: 92 %, bias: 82 %), or using the pipe model theory (nRMSE: 31 %, bias: -27 %). The model was then applied to the whole-tree scale and showed that the sampled trees had more than 1.7 km of structures on average and that 96 % of that length was coming from the twigs (i.e. <5 cm diameter). Our results showed that neglecting twigs can lead to a significant underestimation of tree above-ground woody biomass (-21 %).</p><p><strong>Conclusions: </strong>The structural model approach is an effective method that allows a more accurate estimation of the volumes of smaller branches from lidar point clouds. This method is versatile but requires manual measurements on branches for calibration. Nevertheless, once the model is calibrated, it can provide unbiased and large-scale estimations of tree structure volumes, making it an excellent choice for accurate 3D reconstruction of trees and estimating standing biomass.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141157858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Balzhan Askanbayeva, Jitka Janová, Jiří Kubásek, Viktoria V Zeisler-Diehl, Lukas Schreiber, Christopher D Muir, Jiří Šantrůček
Background and aims: The benefits and costs of amphistomy (AS) vs. hypostomy (HS) are not fully understood. Here, we quantify benefits of access of CO2 through stomata on the upper (adaxial) leaf surface, using 13C abundance in the adaxial and abaxial epicuticular wax. Additionally, a relationship between the distribution of stomata and epicuticular wax on the opposite leaf sides is studied.
Methods: We suggest that the 13C content of long-chain aliphatic compounds of cuticular wax records the leaf internal CO2 concentration in chloroplasts adjacent to the adaxial and abaxial epidermes. This unique property stems from: (1) wax synthesis being located exclusively in epidermal cells; and (2) ongoing wax renewal over the whole leaf lifespan. Compound-specific and bulk wax 13C abundance (δ) was related to amphistomy level (ASL; as a fraction of adaxial in all stomata) of four AS and five HS species grown under various levels of irradiance. The isotopic polarity of epicuticular wax, i.e. the difference in abaxial and adaxial δ (δab - δad), was used to calculate the leaf dorsiventral CO2 gradient. Leaf-side-specific epicuticular wax deposition (amphiwaxy level) was estimated and related to ASL.
Key results: In HS species, the CO2 concentration in the adaxial epidermis was lower than in the abaxial one, independently of light conditions. In AS leaves grown in high-light and low-light conditions, the isotopic polarity and CO2 gradient varied in parallel with ASL. The AS leaves grown in high-light conditions increased ASL compared with low light, and δab - δad approached near-zero values. Changes in ASL occurred concomitantly with changes in amphiwaxy level.
Conclusions: Leaf wax isotopic polarity is a newly identified leaf trait, distinguishing between hypo- and amphistomatous species and indicating that increased ASL in sun-exposed AS leaves reduces the CO2 gradient across the leaf mesophyll. Stomata and epicuticular wax deposition follow similar leaf-side patterning.
背景和目的:目前还不完全清楚两性气孔技术(AS)与假两性气孔技术(HS)的益处和成本。在此,我们利用正面和背面表皮蜡中的 13C 丰度,量化了通过上部(正面)叶面气孔获取 CO2 的益处。此外,还研究了气孔与叶片反面的表皮蜡(EW)分布之间的关系:我们认为,在叶片正面和背面表皮附近的叶绿体中,角质蜡长链脂肪族化合物的 13C 含量记录了叶片内部的二氧化碳浓度。这种独特的特性源于:(i) 蜡的合成完全在表皮细胞中进行;(ii) 蜡的更新在整个叶片生命周期中持续进行。在不同辐照度下生长的四种 AS 和五种 HS 的化合物特异性和大量蜡 13C 丰度(δ)与两面性水平(ASL,所有气孔中正面的比例)相关。EW的同位素极性,即背面和正面δ(δab-δad)之差,被用来计算叶背腹二氧化碳梯度。估计了叶侧特定的 EW 沉积,即两叶水平(AWL),并将其与 ASL 联系起来:主要结果:在 HS 物种中,正面表皮的二氧化碳浓度低于背面表皮,与光照条件无关。在强光和弱光下生长的AS叶片中,同位素极性和二氧化碳梯度与ASL平行变化。与弱光相比,强光下生长的AS叶片ASL增加,δab-δad接近零值。ASL的变化与AWL的变化同时发生:结论:叶蜡同位素极性是一种新发现的叶片特征,它能区分低表皮蜡质和表皮蜡质物种,并表明暴露在阳光下的 AS 叶片中 ASL 的增加会降低叶片中叶的二氧化碳梯度。气孔和表皮蜡沉积遵循类似的叶侧模式。
{"title":"Amphistomy: stomata patterning inferred from 13C content and leaf-side-specific deposition of epicuticular wax.","authors":"Balzhan Askanbayeva, Jitka Janová, Jiří Kubásek, Viktoria V Zeisler-Diehl, Lukas Schreiber, Christopher D Muir, Jiří Šantrůček","doi":"10.1093/aob/mcae082","DOIUrl":"10.1093/aob/mcae082","url":null,"abstract":"<p><strong>Background and aims: </strong>The benefits and costs of amphistomy (AS) vs. hypostomy (HS) are not fully understood. Here, we quantify benefits of access of CO2 through stomata on the upper (adaxial) leaf surface, using 13C abundance in the adaxial and abaxial epicuticular wax. Additionally, a relationship between the distribution of stomata and epicuticular wax on the opposite leaf sides is studied.</p><p><strong>Methods: </strong>We suggest that the 13C content of long-chain aliphatic compounds of cuticular wax records the leaf internal CO2 concentration in chloroplasts adjacent to the adaxial and abaxial epidermes. This unique property stems from: (1) wax synthesis being located exclusively in epidermal cells; and (2) ongoing wax renewal over the whole leaf lifespan. Compound-specific and bulk wax 13C abundance (δ) was related to amphistomy level (ASL; as a fraction of adaxial in all stomata) of four AS and five HS species grown under various levels of irradiance. The isotopic polarity of epicuticular wax, i.e. the difference in abaxial and adaxial δ (δab - δad), was used to calculate the leaf dorsiventral CO2 gradient. Leaf-side-specific epicuticular wax deposition (amphiwaxy level) was estimated and related to ASL.</p><p><strong>Key results: </strong>In HS species, the CO2 concentration in the adaxial epidermis was lower than in the abaxial one, independently of light conditions. In AS leaves grown in high-light and low-light conditions, the isotopic polarity and CO2 gradient varied in parallel with ASL. The AS leaves grown in high-light conditions increased ASL compared with low light, and δab - δad approached near-zero values. Changes in ASL occurred concomitantly with changes in amphiwaxy level.</p><p><strong>Conclusions: </strong>Leaf wax isotopic polarity is a newly identified leaf trait, distinguishing between hypo- and amphistomatous species and indicating that increased ASL in sun-exposed AS leaves reduces the CO2 gradient across the leaf mesophyll. Stomata and epicuticular wax deposition follow similar leaf-side patterning.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341673/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141247436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrea Bilajac, Edi Gljušćić, Shannen Smith, Mirjana Najdek, Ljiljana Iveša
Background and aims: Globally, rising seawater temperatures contribute to the regression of marine macroalgal forests. Along the Istrian coastline (northern Adriatic), an isolated population of Gongolaria barbata persists in a coastal lagoon, representing one of the last marine macroalgal forests in the region. Our objective was to examine the impact of extreme temperatures on the morphology and physiology of G. barbata and test its potential for recovery after simulating marine heatwave (MHW) conditions.
Methods: We explored the occurrence of marine heatwaves in southern Istria, adjacent to the study area, in addition to extreme temperatures inside the area itself. Subsequently, we performed a thermotolerance experiment, consisting of a stress and recovery phase, in which we exposed G. barbata thalli to four extreme (28, 30, 32 and 34 °C) and one favourable (18 °C) temperature. We monitored morphological and physiological responses.
Key results: Our findings indicate a significant rise in frequency, duration and intensity of MHWs over decades on the southern Istrian coast. Experimental results show that G. barbata demonstrates potential for both morphological and physiological recovery after exposure to temperatures as high as 32 °C. However, exposure to 34 °C led to thallus decay, with limited ability to regenerate.
Conclusions: Our results show that G. barbata has a remarkable resilience to long-term exposure to extreme temperatures ≤32 °C and suggest that short-term exposure to temperatures beyond this, as currently recorded inside the lagoon, do not notably affect the physiology or morphology of local G. barbata. With more MHWs expected in the future, such an adapted population might represent an important donor suitable for future restoration activities along the Istrian coast. These results emphasize the resilience of this unique population, but also warn of the vulnerability of marine macroalgal forests to rising seawater temperatures in rapidly changing climatic conditions.
{"title":"Effects of extreme temperatures and recovery potential of Gongolaria barbata from a coastal lagoon in the northern Adriatic Sea: an ex situ approach.","authors":"Andrea Bilajac, Edi Gljušćić, Shannen Smith, Mirjana Najdek, Ljiljana Iveša","doi":"10.1093/aob/mcae038","DOIUrl":"10.1093/aob/mcae038","url":null,"abstract":"<p><strong>Background and aims: </strong>Globally, rising seawater temperatures contribute to the regression of marine macroalgal forests. Along the Istrian coastline (northern Adriatic), an isolated population of Gongolaria barbata persists in a coastal lagoon, representing one of the last marine macroalgal forests in the region. Our objective was to examine the impact of extreme temperatures on the morphology and physiology of G. barbata and test its potential for recovery after simulating marine heatwave (MHW) conditions.</p><p><strong>Methods: </strong>We explored the occurrence of marine heatwaves in southern Istria, adjacent to the study area, in addition to extreme temperatures inside the area itself. Subsequently, we performed a thermotolerance experiment, consisting of a stress and recovery phase, in which we exposed G. barbata thalli to four extreme (28, 30, 32 and 34 °C) and one favourable (18 °C) temperature. We monitored morphological and physiological responses.</p><p><strong>Key results: </strong>Our findings indicate a significant rise in frequency, duration and intensity of MHWs over decades on the southern Istrian coast. Experimental results show that G. barbata demonstrates potential for both morphological and physiological recovery after exposure to temperatures as high as 32 °C. However, exposure to 34 °C led to thallus decay, with limited ability to regenerate.</p><p><strong>Conclusions: </strong>Our results show that G. barbata has a remarkable resilience to long-term exposure to extreme temperatures ≤32 °C and suggest that short-term exposure to temperatures beyond this, as currently recorded inside the lagoon, do not notably affect the physiology or morphology of local G. barbata. With more MHWs expected in the future, such an adapted population might represent an important donor suitable for future restoration activities along the Istrian coast. These results emphasize the resilience of this unique population, but also warn of the vulnerability of marine macroalgal forests to rising seawater temperatures in rapidly changing climatic conditions.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140130503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hong Qian, Alain Vanderpoorten, Zun Dai, Michael Kessler, Thibault Kasprzyk, Jian Wang
Background and aims: Latitudinal diversity gradients have been intimately linked to the tropical niche conservatism hypothesis, which posits that there has been a strong filter due to the challenges faced by ancestral tropical lineages to adapt to low temperatures and colonize extra-tropical regions. In liverworts, species richness is higher towards the tropics, but the centres of diversity of the basal lineages are distributed across extra-tropical regions, pointing to the colonization of tropical regions by phylogenetically clustered assemblages of species of temperate origin. Here, we test this hypothesis through analyses of the relationship between macroclimatic variation and phylogenetic diversity in Chinese liverworts.
Methods: Phylogenetic diversity metrics and their standardized effect sizes for liverworts in each of the 28 regional floras at the province level in China were related to latitude and six climate variables using regression analysis. We conducted variation partitioning analyses to determine the relative importance of each group of climatic variables.
Key results: We find that the number of species decreases with latitude, whereas phylogenetic diversity shows the reverse pattern, and that phylogenetic diversity is more strongly correlated with temperature-related variables compared with precipitation-related variables.
Conclusions: We interpret the opposite patterns observed in phylogenetic diversity and species richness in terms of a more recent origin of tropical diversity coupled with higher extinctions in temperate regions.
{"title":"Spatial patterns and climatic drivers of phylogenetic structure of regional liverwort assemblages in China.","authors":"Hong Qian, Alain Vanderpoorten, Zun Dai, Michael Kessler, Thibault Kasprzyk, Jian Wang","doi":"10.1093/aob/mcae080","DOIUrl":"10.1093/aob/mcae080","url":null,"abstract":"<p><strong>Background and aims: </strong>Latitudinal diversity gradients have been intimately linked to the tropical niche conservatism hypothesis, which posits that there has been a strong filter due to the challenges faced by ancestral tropical lineages to adapt to low temperatures and colonize extra-tropical regions. In liverworts, species richness is higher towards the tropics, but the centres of diversity of the basal lineages are distributed across extra-tropical regions, pointing to the colonization of tropical regions by phylogenetically clustered assemblages of species of temperate origin. Here, we test this hypothesis through analyses of the relationship between macroclimatic variation and phylogenetic diversity in Chinese liverworts.</p><p><strong>Methods: </strong>Phylogenetic diversity metrics and their standardized effect sizes for liverworts in each of the 28 regional floras at the province level in China were related to latitude and six climate variables using regression analysis. We conducted variation partitioning analyses to determine the relative importance of each group of climatic variables.</p><p><strong>Key results: </strong>We find that the number of species decreases with latitude, whereas phylogenetic diversity shows the reverse pattern, and that phylogenetic diversity is more strongly correlated with temperature-related variables compared with precipitation-related variables.</p><p><strong>Conclusions: </strong>We interpret the opposite patterns observed in phylogenetic diversity and species richness in terms of a more recent origin of tropical diversity coupled with higher extinctions in temperate regions.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341670/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141096848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giacomo Mozzi, Alan Crivellaro, Davis E Blasini, Marilyn Vásquez-Cruz, Tania Hernández-Hernández, Kevin R Hultine
Background and scope: Plant functional traits are the result of natural selection to optimize carbon gain, leading to a broad spectrum of traits across environmental gradients. Among plant traits, leaf water storage capacity is paramount for plant drought resistance. We explored whether leaf-succulent taxa follow trait correlations similar to those of non-leaf-succulent taxa to evaluate whether both are similarly constrained by relationships between leaf water storage and climate.
Methods: We tested the relationships among three leaf traits related to water storage capacity and resource use strategies in 132 species comprising three primary leaf types: succulent, sclerophyllous, and leaves with rapid returns on water investment, referred to as fast return. Correlation coefficients among specific leaf area (SLA), water mass per unit of area (WMA), and saturated water content (SWC) were tested, along with relationships between leaf trait spectra and aridity determined from species occurrence records.
Results: Both SWC and WMA at a given SLA were ~10-fold higher in succulent leaves than in non-succulent leaves. While SWC actually increased with SLA in non-succulent leaves, no relationship was detected between SWC and SLA in succulent leaves, although WMA decreased with SLA in all leaf types. A principal component analysis (PCA) revealed that succulent taxa occupied a widely different mean trait space than either fast-return (P < 0.0001) or sclerophyllous (P < 0.0001) taxa along the first PCA axis, which explained 63 % of mean trait expression among species. However, aridity only explained 12 % of the variation in PCA1 values. This study is among the first to establish a structural leaf trait spectrum in succulent leaf taxa and quantify contrasts in leaf water storage among leaf types relative to specific leaf area.
Conclusions: Trait coordination in succulent leaf taxa may not follow patterns similar to those of widely studied non-succulent taxa.
{"title":"Divergent structural leaf trait spectra in succulent versus non-succulent plant taxa.","authors":"Giacomo Mozzi, Alan Crivellaro, Davis E Blasini, Marilyn Vásquez-Cruz, Tania Hernández-Hernández, Kevin R Hultine","doi":"10.1093/aob/mcae093","DOIUrl":"10.1093/aob/mcae093","url":null,"abstract":"<p><strong>Background and scope: </strong>Plant functional traits are the result of natural selection to optimize carbon gain, leading to a broad spectrum of traits across environmental gradients. Among plant traits, leaf water storage capacity is paramount for plant drought resistance. We explored whether leaf-succulent taxa follow trait correlations similar to those of non-leaf-succulent taxa to evaluate whether both are similarly constrained by relationships between leaf water storage and climate.</p><p><strong>Methods: </strong>We tested the relationships among three leaf traits related to water storage capacity and resource use strategies in 132 species comprising three primary leaf types: succulent, sclerophyllous, and leaves with rapid returns on water investment, referred to as fast return. Correlation coefficients among specific leaf area (SLA), water mass per unit of area (WMA), and saturated water content (SWC) were tested, along with relationships between leaf trait spectra and aridity determined from species occurrence records.</p><p><strong>Results: </strong>Both SWC and WMA at a given SLA were ~10-fold higher in succulent leaves than in non-succulent leaves. While SWC actually increased with SLA in non-succulent leaves, no relationship was detected between SWC and SLA in succulent leaves, although WMA decreased with SLA in all leaf types. A principal component analysis (PCA) revealed that succulent taxa occupied a widely different mean trait space than either fast-return (P < 0.0001) or sclerophyllous (P < 0.0001) taxa along the first PCA axis, which explained 63 % of mean trait expression among species. However, aridity only explained 12 % of the variation in PCA1 values. This study is among the first to establish a structural leaf trait spectrum in succulent leaf taxa and quantify contrasts in leaf water storage among leaf types relative to specific leaf area.</p><p><strong>Conclusions: </strong>Trait coordination in succulent leaf taxa may not follow patterns similar to those of widely studied non-succulent taxa.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341667/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141247445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiří Doležal, Thinles Chondol, Zuzana Chlumská, Jan Altman, Kateřina Čapková, Miroslav Dvorský, Pavel Fibich, Kirill A Korznikov, Adam T Ruka, Martin Kopecký, Martin Macek, Klára Řeháková
Background and aims: Understanding biomass allocation among plant organs is crucial for comprehending plant growth optimization, survival and responses to the drivers of global change. Yet, the mechanisms governing mass allocation in vascular plants from extreme elevations exposed to cold and drought stresses remain poorly understood.
Methodology: We analysed organ mass weights and fractions in 258 Himalayan herbaceous species across diverse habitats (wetland, steppe, alpine), growth forms (annual, perennial taprooted, rhizomatous and cushiony) and climatic gradients (3500-6150 m elevation) to explore whether biomass distribution adhered to fixed allometric or optimal partitioning rules, and how variations in size, phylogeny and ecological preferences influence their strategies for resource allocation.
Key findings: Following optimal partitioning theory, Himalayan plants distribute more biomass to key organs vital for acquiring and preserving limited resources necessary for their growth and survival. Allocation strategies are mainly influenced by plant growth forms and habitat conditions, notably temperature, water availability and evaporative demands. Alpine plants invest primarily in below-ground stem bases for storage and regeneration, reducing above-ground stems while increasing leaf mass fraction to maximize carbon assimilation in their short growing season. Conversely, arid steppe plants prioritize deep roots over leaves to secure water and minimize transpiration. Wetland plants allocate resources to above-ground stems and below-ground rhizomes, enabling them to resist competition and grazing in fertile environments.
Conclusions: Himalayan plants from extreme elevations optimize their allocation strategies to acquire scarce resources under specific conditions, efficiently investing carbon from supportive to acquisitive and protective functions with increasing cold and drought. Intraspecific variation and shared ancestry have not significantly altered biomass allocation strategies of Himalayan plants. Despite diverse evolutionary histories, plants from similar habitats have developed comparable phenotypic structures to adapt to their specific environments. This study offers new insights into plant adaptations in diverse Himalayan environments and underscores the importance of efficient resource allocation for survival and growth in challenging conditions.
{"title":"Contrasting biomass allocations explain adaptations to cold and drought in the world's highest-growing angiosperms.","authors":"Jiří Doležal, Thinles Chondol, Zuzana Chlumská, Jan Altman, Kateřina Čapková, Miroslav Dvorský, Pavel Fibich, Kirill A Korznikov, Adam T Ruka, Martin Kopecký, Martin Macek, Klára Řeháková","doi":"10.1093/aob/mcae028","DOIUrl":"10.1093/aob/mcae028","url":null,"abstract":"<p><strong>Background and aims: </strong>Understanding biomass allocation among plant organs is crucial for comprehending plant growth optimization, survival and responses to the drivers of global change. Yet, the mechanisms governing mass allocation in vascular plants from extreme elevations exposed to cold and drought stresses remain poorly understood.</p><p><strong>Methodology: </strong>We analysed organ mass weights and fractions in 258 Himalayan herbaceous species across diverse habitats (wetland, steppe, alpine), growth forms (annual, perennial taprooted, rhizomatous and cushiony) and climatic gradients (3500-6150 m elevation) to explore whether biomass distribution adhered to fixed allometric or optimal partitioning rules, and how variations in size, phylogeny and ecological preferences influence their strategies for resource allocation.</p><p><strong>Key findings: </strong>Following optimal partitioning theory, Himalayan plants distribute more biomass to key organs vital for acquiring and preserving limited resources necessary for their growth and survival. Allocation strategies are mainly influenced by plant growth forms and habitat conditions, notably temperature, water availability and evaporative demands. Alpine plants invest primarily in below-ground stem bases for storage and regeneration, reducing above-ground stems while increasing leaf mass fraction to maximize carbon assimilation in their short growing season. Conversely, arid steppe plants prioritize deep roots over leaves to secure water and minimize transpiration. Wetland plants allocate resources to above-ground stems and below-ground rhizomes, enabling them to resist competition and grazing in fertile environments.</p><p><strong>Conclusions: </strong>Himalayan plants from extreme elevations optimize their allocation strategies to acquire scarce resources under specific conditions, efficiently investing carbon from supportive to acquisitive and protective functions with increasing cold and drought. Intraspecific variation and shared ancestry have not significantly altered biomass allocation strategies of Himalayan plants. Despite diverse evolutionary histories, plants from similar habitats have developed comparable phenotypic structures to adapt to their specific environments. This study offers new insights into plant adaptations in diverse Himalayan environments and underscores the importance of efficient resource allocation for survival and growth in challenging conditions.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341669/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139970791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maaike J Bierenbroodspot, Thomas Pröschold, Janine M R Fürst-Jansen, Sophie de Vries, Iker Irisarri, Tatyana Darienko, Jan de Vries
The Streptophyta emerged about a billion years ago. Nowadays, this branch of the green lineage is most famous for one of its clades, the land plants (Embryophyta). Although Embryophyta make up the major share of species numbers in Streptophyta, there is a diversity of probably >5000 species of streptophyte algae that form a paraphyletic grade next to land plants. Here, we focus on the deep divergences that gave rise to the diversity of streptophytes, hence particularly on the streptophyte algae. Phylogenomic efforts have not only clarified the position of streptophyte algae relative to land plants, but recent efforts have also begun to unravel the relationships and major radiations within streptophyte algal diversity. We illustrate how new phylogenomic perspectives have changed our view on the evolutionary emergence of key traits, such as intricate signalling networks that are intertwined with multicellular growth and the chemodiverse hotbed from which they emerged. These traits are key for the biology of land plants but were bequeathed from their algal progenitors.
{"title":"Phylogeny and evolution of streptophyte algae.","authors":"Maaike J Bierenbroodspot, Thomas Pröschold, Janine M R Fürst-Jansen, Sophie de Vries, Iker Irisarri, Tatyana Darienko, Jan de Vries","doi":"10.1093/aob/mcae091","DOIUrl":"10.1093/aob/mcae091","url":null,"abstract":"<p><p>The Streptophyta emerged about a billion years ago. Nowadays, this branch of the green lineage is most famous for one of its clades, the land plants (Embryophyta). Although Embryophyta make up the major share of species numbers in Streptophyta, there is a diversity of probably >5000 species of streptophyte algae that form a paraphyletic grade next to land plants. Here, we focus on the deep divergences that gave rise to the diversity of streptophytes, hence particularly on the streptophyte algae. Phylogenomic efforts have not only clarified the position of streptophyte algae relative to land plants, but recent efforts have also begun to unravel the relationships and major radiations within streptophyte algal diversity. We illustrate how new phylogenomic perspectives have changed our view on the evolutionary emergence of key traits, such as intricate signalling networks that are intertwined with multicellular growth and the chemodiverse hotbed from which they emerged. These traits are key for the biology of land plants but were bequeathed from their algal progenitors.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341676/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141236623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to: Functional analysis of the heterotrimeric NF-Y transcription factor complex in cassava disease resistance.","authors":"","doi":"10.1093/aob/mcae134","DOIUrl":"https://doi.org/10.1093/aob/mcae134","url":null,"abstract":"","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142016133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background and aims: Changing precipitation regimes can influence terrestrial plants and ecosystems. However, plant phenological responses to changing precipitation temporal patterns and the underlying mechanisms are largely unclear. This study was conducted to explore the effects of seasonal precipitation redistribution on plant reproductive phenology in a temperate steppe.
Methods: A field experiment with control (C), advanced (AP) and delayed (DP) growing-season precipitation peaks, and the combination of AP and DP (ADP) were employed. Seven dominant plant species were selected and divided into two functional groups (early- vs. middle-flowering species, shallow- vs. deep-rooted species) to monitor reproductive phenology including budding, flowering, and fruiting date, as well as reproductive duration for four growing seasons from 2015 to 2017, and 2022.
Key results: The AP, but not DP treatment advanced the phenological (i.e., budding, flowering, and fruiting) dates and lengthened the reproductive duration across the 4 growing seasons and 7 monitored species. In addition, the phenological responses showed divergent patterns among different plant functional groups, which could be attributed to shifts in soil moisture and its variability in different months and soil depths. Moreover, species with lengthened reproductive duration increased phenological overlap with other species, which could have a negative impact on their dominance under the AP treatment.
Conclusions: Our findings reveal that changing precipitation seasonality could have considerable impacts on plant phenology by affecting soil water availability and variability. Incorporating these two factors simultaneously in the phenology models will help us understand the response of plant phenology under intensified changing precipitation scenarios. In addition, the observations of decreased dominance for the species with lengthened reproductive duration suggest that changing reproductive phenology can have a potential to affect community composition in grasslands under global change.
背景和目的:降水机制的变化会影响陆生植物和生态系统。然而,植物对降水时间模式变化的物候反应及其内在机制在很大程度上还不清楚。本研究旨在探索季节性降水再分配对温带草原植物生殖物候的影响:方法:采用生长季降水峰值对照(C)、生长季降水峰值提前(AP)、生长季降水峰值延迟(DP)以及生长季降水峰值提前与生长季降水峰值延迟相结合(ADP)的田间试验。选取了七种优势植物并将其分为两个功能组(早花与中花物种、浅根与深根物种),以监测2015年至2017年以及2022年四个生长季的生殖物候,包括萌芽、开花、结果日期以及生殖持续时间:在 4 个生长季和 7 个监测物种中,AP 处理(而非 DP 处理)提前了物候期(即萌芽期、开花期和结果期),延长了生殖持续时间。此外,不同植物功能群的物候反应呈现出不同的模式,这可能是由于土壤水分的变化及其在不同月份和土壤深度的变化造成的。此外,生殖期延长的物种与其他物种的物候重叠增加,这可能会对它们在 AP 处理下的优势地位产生负面影响:我们的研究结果表明,降水季节性的变化会影响土壤水分的可用性和可变性,从而对植物物候产生重大影响。将这两个因素同时纳入物候学模型将有助于我们了解植物物候学在降水变化加剧情况下的反应。此外,对生殖持续时间延长的物种的优势地位下降的观察表明,生殖物候的变化有可能影响全球变化下草地的群落组成。
{"title":"Seasonal and vertical patterns of water availability and variability determine plant reproductive phenology.","authors":"Zhenxing Zhou, Hanlin Feng, Gaigai Ma, Jingyi Ru, Haidao Wang, Jiayin Feng, Shiqiang Wan","doi":"10.1093/aob/mcae138","DOIUrl":"https://doi.org/10.1093/aob/mcae138","url":null,"abstract":"<p><strong>Background and aims: </strong>Changing precipitation regimes can influence terrestrial plants and ecosystems. However, plant phenological responses to changing precipitation temporal patterns and the underlying mechanisms are largely unclear. This study was conducted to explore the effects of seasonal precipitation redistribution on plant reproductive phenology in a temperate steppe.</p><p><strong>Methods: </strong>A field experiment with control (C), advanced (AP) and delayed (DP) growing-season precipitation peaks, and the combination of AP and DP (ADP) were employed. Seven dominant plant species were selected and divided into two functional groups (early- vs. middle-flowering species, shallow- vs. deep-rooted species) to monitor reproductive phenology including budding, flowering, and fruiting date, as well as reproductive duration for four growing seasons from 2015 to 2017, and 2022.</p><p><strong>Key results: </strong>The AP, but not DP treatment advanced the phenological (i.e., budding, flowering, and fruiting) dates and lengthened the reproductive duration across the 4 growing seasons and 7 monitored species. In addition, the phenological responses showed divergent patterns among different plant functional groups, which could be attributed to shifts in soil moisture and its variability in different months and soil depths. Moreover, species with lengthened reproductive duration increased phenological overlap with other species, which could have a negative impact on their dominance under the AP treatment.</p><p><strong>Conclusions: </strong>Our findings reveal that changing precipitation seasonality could have considerable impacts on plant phenology by affecting soil water availability and variability. Incorporating these two factors simultaneously in the phenology models will help us understand the response of plant phenology under intensified changing precipitation scenarios. In addition, the observations of decreased dominance for the species with lengthened reproductive duration suggest that changing reproductive phenology can have a potential to affect community composition in grasslands under global change.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142008176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fertilization relies on pollen mother cells able to transit from mitosis to meiosis to supply gametes. This process involves remarkable changes at the molecular, cellular and physiological levels including (but not limited to) remodelling of the cell wall. During the meiosis onset, cellulose content at the pollen mother cell walls gradually declines with the concurrent deposition of the polysaccharide callose in anther locules. We aim to understand the biological significance of cellulose-to-callose turnover in pollen mother cells walls using electron microscopic analyses of rice flowers. Our observations indicate that in wild type rice anthers, the mitosis-to-meiosis transition coincides with a gradual reduction in the number of cytoplasmic connections called plasmodesmata. A mutant in the Oryza sativa callose synthase GSL5 (Osgsl5-3), impaired in callose accumulation in premeiotic and meiotic anthers, displayed a greater reduction in plasmodesmata frequency among pollen mother cells and tapetal cells suggesting a role for callose in plasmodesmata maintenance. In addition, a significant increase in extracellular distance between pollen mother cells and impaired premeiotic cell shaping was observed in the Osgsl5-3 mutant. The results suggest that callose-to-cellulose turnover during mitosis-meiosis transition is necessary to maintain cell-to-cell connections and optimal extracellular distance among the central anther locular cells. Findings of this study contribute to our understanding of the regulatory influence of callose metabolism during meiosis initiation in flowering plants.
{"title":"Callose Deficiency Modulates Plasmodesmata Frequency and Extracellular Distance in Rice Pollen Mother and Tapetal cells.","authors":"Harsha Somashekar, Keiko Takanami, Yoselin Benitez-Alfonso, Akane Oishi, Rie Hiratsuka, Ken-Ichi Nonomura","doi":"10.1093/aob/mcae137","DOIUrl":"https://doi.org/10.1093/aob/mcae137","url":null,"abstract":"<p><p>Fertilization relies on pollen mother cells able to transit from mitosis to meiosis to supply gametes. This process involves remarkable changes at the molecular, cellular and physiological levels including (but not limited to) remodelling of the cell wall. During the meiosis onset, cellulose content at the pollen mother cell walls gradually declines with the concurrent deposition of the polysaccharide callose in anther locules. We aim to understand the biological significance of cellulose-to-callose turnover in pollen mother cells walls using electron microscopic analyses of rice flowers. Our observations indicate that in wild type rice anthers, the mitosis-to-meiosis transition coincides with a gradual reduction in the number of cytoplasmic connections called plasmodesmata. A mutant in the Oryza sativa callose synthase GSL5 (Osgsl5-3), impaired in callose accumulation in premeiotic and meiotic anthers, displayed a greater reduction in plasmodesmata frequency among pollen mother cells and tapetal cells suggesting a role for callose in plasmodesmata maintenance. In addition, a significant increase in extracellular distance between pollen mother cells and impaired premeiotic cell shaping was observed in the Osgsl5-3 mutant. The results suggest that callose-to-cellulose turnover during mitosis-meiosis transition is necessary to maintain cell-to-cell connections and optimal extracellular distance among the central anther locular cells. Findings of this study contribute to our understanding of the regulatory influence of callose metabolism during meiosis initiation in flowering plants.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}