Local dynamic stability in turning and straight-line gait

Successful community and household ambulation require the ability to navigate corners and maneuver around obstacles, posing unique challenges compared to straight-line walking. The challenges associated with turning may contribute to an increased incidence of falling and the occurrence of fall-related injuries. A measure of stability applied to turning gait may be able to quantify a system's response to naturally occurring disturbances associated with turning and identify subjects at greater risk of falling. An index of stability has been used previously to assess the rate of kinematic separation (local dynamic stability) during straight-line gait. The purpose of this study was to determine if local dynamic stability during constant speed turning is reduced compared to straight-line treadmill walking. Maximum finite-time Lyapunov exponents (λ) were used to estimate the local stability of able-bodied subjects’ (n=19) sagittal plane hip, knee, and ankle trajectories for turning compared to straight-line walking at two different walking speeds. Turning λ was greater than straight λ for the hip, right knee, and ankle (p<0.05). Turning λ for the left knee angle was similar to straight λ. There were no differences in λ between left and right limbs for the hip and ankle and also no differences between the inside and outside limbs during turning for all joints. These findings indicate able-bodied subjects’ hip, right knee, and ankle kinematics are less locally stable while turning than walking in a straight line and may be used as a comparative tool for determining the efficacy of therapeutic interventions for mobility-impaired populations.     

The influence of circulation frequency on fungal morphology: a case study considering Kolmogorov microscale in constant specific energy dissipation rate cultures of Trichoderma harzianum

The energy dissipation/circulation function (EDCF) is the product of the specific energy dissipation rate in the impeller swept volume (P/kD³) and the frequency of particle circulation (1/t_c) through that volume. A direct relationship between mycelial fragmentation and EDCF has been reported. However, and although hyphal fragmentation is assumed to occur by hyphae-eddy interaction, Kolmogorov microscale (λ) has not been shown to determine, at least directly, fungal morphology. In this work we studied the influence of λ and EDCF evolution, as well as the individual effects of P/kD³ and 1/t_c, on Trichoderma harzianum cultures in an attempt to elucidate the mechanistic interactions between parameters. T. harzianum cultures, conducted at equivalent yielding P/kD³ conditions, were developed using two different Rushton turbines diameter sets. For the studied conditions, 1/t_c had a greater effect over mycelial clump size and growth rate than P/kD³. Consequently, broth viscosity, and hence Kolmogorov microscale, was a function of impeller diameter, even among cultures operated at equivalent specific energy dissipation rates. The latter could partially explain why Kolmogorv's theory has not been able to fully correlate morphological data, and highlights the importance of 1/t_c on fungal bioprocesses. A theoretical approach to monitor λ in large-scale bioreactors is proposed.     

A new formalization of a meta-game using the lambda calculus

This paper presents a new game system formalism. The system describes both strategies and a game master (who computes scores in a given game system) in terms of λ-calculus. This formalism revisits the prisoner's dilemma game, to discuss how meta-strategies emerge in this classical game, even without repetition. We have also examined the evolution of meta-strategies in λ formalism.     

Regrowth following ungulate herbivory in Ipomopsis aggregata: geographic evidence for overcompensation

Studies were conducted on eight populations of scarlet gilia, Ipomopsis aggregata, across Colorado and in northern Arizona, to assess the fitness consequences of natural and simulated herbivory. To date, geographic studies have failed to incorporate treatment groups that included naturally browsed plants along with clipping treatments. The results presented here clearly demonstrate the importance of assessing, a priori, whether or not clipping experiments accurately reflect natural patterns of herbivory. Although because of the timing of the clip no evidence of overcompensation was found in any of the Colorado populations when ungulate herbivory was simulated in experimental clipping treatments, evidence for overcompensation was found in more than half the populations when plants that were naturally browsed and matched for size using root diameters were included early in the season. Matching plants for size based on root diameter late in the season would be problematic because root diameters significantly increased in size in all eight populations following high levels of ungulate herbivory and/or experimental clipping. Results from this study, and other recent studies on another biennial herb, the field gentian, clearly demonstrate that overcompensation is not only a real phenomenon but also is more widespread, both taxonomically and geographically, than previously thought. Received: 15 July 1998 / Accepted: 9 November 1998     

Temporal quota corrections based on timing of harvest in a small game species

Theoretical models have shown that the effect of removing a given proportion of the population can be profoundly different if the harvest takes place late in the season compared to early. We explore the effect of these differences using theoretical models based on the concept of demographic value and empirical data on seasonal patterns of natural mortality risk in two contrasting populations of willow ptarmigan in Norway. Based on the theoretical models, we found that changes in the timing of harvest have a much stronger effect in populations with relatively low annual survival compared to populations characterized by longevity typical for species with slow life histories. Also, the timing of harvest is more influential in cases with constant mortality hazards compared to a situation with density-dependent natural mortality. Empirical data from two study populations of willow ptarmigan showed large deviations from the theoretical predictions of models with both constant and density-dependent mortality hazards. There were also large differences in both the temporal pattern and magnitude of annual survival between the two ptarmigan populations (54 vs 26% annual survival). Site differences illustrate the importance of knowledge of both the magnitude and temporal pattern of natural mortality hazard to be able to correctly predict the effect of changing the timing of harvest in a population. In the two ptarmigan populations, we show how harvest quotas can be adjusted in accordance to the empirical estimates of natural mortality risk and how this determines the effects of shifting from harvesting early to late in the annual cycle.     

蒸散发广义互补原理中关键参数αe的时空变化特征及计算方法分析

蒸散发广义互补原理是实测数据稀少条件下估算蒸散发的重要方法, 其中准确估算参数α_e是应用该方法的关键。该研究利用中国不同气候和生态类型的8个通量站数据, 首先基于实测数据校准得到α_e年值及月值, 探究α_e的时空变异性并对比使用不同时间尺度的α_e对广义互补原理模型计算精度的影响。考虑到实际情况下蒸散发实测数据缺乏而无法校准得到α_e, 进一步探究两个基于干旱系数(AI)的α_e年值统计模型(下称Liu法和Brutsaert法)在站点尺度的适用性, 明确α_e是否可以利用AI确定, 最后探讨各计算方法的误差来源。主要结论如下: 1)季节变化影响α_e, 不同通量站α_e月值变化规律有所差异; 在空间变化上, 湿润站点α_e年值总体大于干旱站点。Liu法和Brutsaert法计算的α_e接近年校准值。2)在应用广义互补原理模型时, 使用校准α_e年值能取得较好的模拟精度, 使用各月份α_e时精度进一步提升。两种基于AI的免校准方法取得较好的模拟效果, 当缺少实测数据而无法校准α_e时, 基于AI计算α_e具有较大的潜力。3)使用校准α_e年值时广义互补原理模型能模拟出蒸散发的年内变化趋势, 但在部分月份估算值出现偏差。Liu法和Brutsaert法计算的蒸散发在干旱站点的夏季月份呈现低估现象, 原因可能在于高估了降雨集中的夏季月份的AI。结果也进一步验证了广义互补原理在估算广泛不同的自然环境下的蒸散发的潜力。     

Leaf compensatory growth as a tolerance strategy to resist herbivory in Pancratium sickenbergeri

We examined the effects of leaf herbivory by the dorcas gazelle, Gazella dorcas, on the compensatory growth of the geophyte Pancratium sickenbergeri (Amaryllidaceae) in the Negev desert, Israel. In three populations exposed to different levels of herbivory, we removed different amounts of photosynthetic leaf area from plants in five clipping treatments: 0, 25, 50%-dispersed over all leaves, 50%-entire area of half the leaves, 100%. The population with the lowest level of herbivory showed the lowest relative regrowth rate after clipping. In the population with a constantly high level of herbivory, plants in intermediate-clipping treatments overcompensated in leaf area after clipping. For all the populations, clipped plants produce more new leaves than unclipped plants. In the population with the highest level of herbivory, clipping treatments did not have a significant effect on the number of fruits per plant. In addition, we did not find a trade-off between investments in growth and reproduction in this population. Our results indicated that, in the desert lily, herbivores may select for plant mechanisms that compensate after damage as a tolerant strategy to maintain fitness.     

Differences in vital demographic rates in three populations of the epiphytic bromeliad, Werauhia sanguinolenta

Since the response to differences in resource availability is most pronounced in smaller individuals of vascular epiphytes such as Werauhia sanguinolenta Cogn. et Marchal (Bromeliaceae), I expected variation in growth and survival of small individuals to play an important role in the dynamics of entire populations. Four annual censuses (2002–2005) of three study populations, which were located across the isthmus of Panama, allowed me to construct stage transition matrices, and to conduct growth analysis and elasticity analysis. Differences between populations were highly consistent through time, but, contrary to expectations, hardly related to the comportment of smaller plants. For example, although average mortality rates were highest at the driest site, close to the Pacific, small plants were not predominantly affected. Similarly, although the highest relative growth rates (RGR) of individuals and the highest population growth rates (λ) were found in the population with the highest moisture input, which was located close to the Atlantic coast, this was not due to a particularly strong stimulation of RGR in small plants. Elasticity analysis indicated rather small differences in the importance of the three demographic processes growth, survival, and reproduction for population growth in the three populations, but invariably identified the survival of large tanks as the single most important process determining λ.     

Measurement and modelling of ABA signalling in potato (Solanum tuberosum L.) during partial root-zone drying

The objective of this study was to develop a simple mechanistic model to predict the magnitude of ABA signalling ([X-ABA]) of potatoes (Solanum tuberosum L.) exposed to partial root-zone drying (PRD). Potatoes were grown in pots in a glasshouse with the roots split equally between two soil columns. At tuber initiation stage, plants were subjected to three irrigation treatments: (1) both soil columns were fully irrigated (FI) daily to a volumetric soil water content (θ) of 18.0%; (2) PRD, in which one soil column was irrigated daily to 18.0% while the other was allowed to dry, and the irrigation was shifted between columns when the θ of the drying soil column had decreased to 7–8%; (3) non-irrigation (NI), where irrigation was withheld after onset of treatments and lasted for 5 days until θ had decreased to 7%. In the PRD plants, the fraction of soil water extraction (FSWE) by the dry roots declined exponentially with declining soil water potential (Ψ_soil-dry); however, after shifting of irrigation, the previously dried roots immediately recovered the full capacity of water uptake. During the first PRD drying cycle, FI plants had the highest stomatal conductance (g_s), and followed by PRD plants and NI plants had the lowest g_s. Photosynthesis (A) was similar for FI and PRD plants, and was significantly lower for the NI plants only on 3–4 days after treatment. In the NI plants, a linear relationship between Ψ_soil and [X-ABA] was obtained. Based on these relationships, a simple model predicting [X-ABA] in the PRD plants ([X-ABA]_PRD) was developed. Assuming that a constant [X-ABA] of 115 nM (similar to that found in the FI plants) originated from the wet roots; the simulation results indicated that irrigation should be shifted between the two sides when Ψ_soil-dry had decreased to −80 kPa, and [X-ABA]_PRD had reached a peak of ca. 150 nM. However, the [X-ABA]_PRD predicted by the model was significantly lower than the measured value; whilst a simple average of [X-ABA] from the wet and the dry soil columns based on the [X-ABA]–Ψ_soil relationship better predicted [X-ABA]_PRD.     

The multicomponent phytopharmaceutical SKI306X inhibits in vitro cartilage degradation and the production of inflammatory mediators

Clinical studies have demonstrated that SKI306X, a purified preparation of three medicinal plants, relieves joint pain and improves functionality in osteoarthritis patients. To study the biological action of SKI306X, bovine cartilage explants and human peripheral blood mononuclear cells (PBMC) were stimulated with IL-1β and lipopolysaccharide (LPS) respectively, in the presence or absence of SKI306X and its individual composites. All tested compounds inhibited dose-dependently IL-1β-induced proteoglycan release and nitric oxide production by cartilage, indicating cartilage protective activity. SKI306X and two of its compounds inhibited PGE₂, TNF- and IL-1β production by LPS-stimulated PBMC, indicating anti-inflammatory activity. These results demonstrate that the biological effect of SKI306X is at least bipartite: (1) cartilage protective and (2) anti-inflammatory. The observed anti-inflammatory effects may provide an explanation for the outcome of the clinical studies. Long-term clinical trails are necessary to elucidate whether the in vitro cartilage protective activity results in disease-modifying effects.     

Ontogenetic contingency of tolerance mechanisms in response to apical damage

Background and Aims

Plants are able to tolerate tissue loss through vigorous branching which is often triggered by release from apical dominance and activation of lateral meristems. However, damage-induced branching might not be a mere physiological outcome of released apical dominance, but an adaptive response to environmental signals, such as damage timing and intensity. Here, branching responses to both factors were examined in the annual plant Medicago truncatula.

Methods

Branching patterns and allocation to reproductive traits were examined in response to variable clipping intensities and timings in M. truncatula plants from two populations that vary in the onset of reproduction. Phenotypic selection analysis was used to evaluate the strength and direction of selection on branching under the damage treatments.

Key Results

Plants of both populations exhibited an ontogenetic shift in tolerance mechanisms: while early damage induced greater meristem activation, late damage elicited investment in late-determined traits, including mean pod and seed biomass, and supported greater germination rates. Severe damage mostly elicited simultaneous development of multiple-order lateral branches, but this response was limited to early damage. Selection analyses revealed positive directional selection on branching in plants under early- compared with late- or no-damage treatments.

Conclusions

The results demonstrate that damage-induced meristem activation is an adaptive response that could be modified according to the plant''s developmental stage, severity of tissue loss and their interaction, stressing the importance of considering these effects when studying plastic responses to apical damage.     

Temporal and spatial variability of the oxygen isotopic composition of massive corals from the South China Sea: Influence of the Asian monsoon

Coral colonies of Porites lutea and P. lobata were collected from areas to the east and south offshore of Hainan Island, South China Sea. Oxygen isotope ratios, ¹⁸O/¹⁶O, were analyzed along the major axis of growth at a resolution of 25–28 samples within an annual band from three colonies, giving data series lengths of 15, 20 and 30 years. Coral δ¹⁸O correlates well with sea surface temperature (SST) throughout most years, particularly when the Asian winter monsoon prevails over the region. Due to the same seasonal phases of SST and sea surface salinity (SSS), it is estimated that most of the seasonal features of coral δ¹⁸O are controlled by changes in SST with a significant contribution of SSS. This indicates the importance of temperature, as determined by the Asian winter monsoon, as a control on seasonal coral δ¹⁸O variations in the South China Sea. Given the fact that annual SSS maxima show minor inter-annual changes, the inter-annual change of annual coral δ¹⁸O maximum mainly reflects the SST induced by the winter monsoon. While the coral δ¹⁸O is mainly controlled by SST, deviations of the δ¹⁸O from SST correlate statistically with sea surface salinity, particularly for summer extreme events when SST reaches its annual maximum with minor inter-annual change. Therefore, we suggest that the inter-annual variation of the annual coral δ¹⁸O minima is mainly controlled by seawater composition. Seawater composition analysis indicates that its δ¹⁸O and salinity are simultaneously affected by freshwater inputs primarily from precipitation, which is mainly supplied by the Asian summer monsoon. Thus seasonal alternations of the winter and summer monsoon mainly control the coral δ¹⁸O, thereby allowing reconstruction of these monsoonal variables. The three coral records consistently reveal clear inter-decadal trends in δ¹⁸O — a gradual increase from 1968 to 1987, and a subsequent decrease from 1987 to 2003. These inter-decadal trends are roughly consistent with salinity changes — but not with temperature and precipitation, suggesting that seawater composition controlled by freshwater inputs from distant source areas, rather than from local precipitation, is responsible for the trends in seawater composition and coral δ¹⁸O over the last 30 years. Comparison of the three coral records indicates that spatial variations in coral δ¹⁸O coincide with variations in seawater salinity and local precipitation, but not with temperature. This confirms the dominant role of seawater composition, mainly controlled by monsoonal precipitation, on the spatial variability of coral δ¹⁸O in the South China Sea.     

Charophyte growth in small temperate water bodies: Extreme isotopic disequilibrium and implications for the palaeoecology of shallow marl lakes

A small pond containing the charophyte Chara hispida was monitored over a one-year period for changes in growth, water chemistry, water level and stable isotopic composition. Chara growth was found to be seasonal, with maximum growth occurring from late April to July. During this period, pH rose to > 10 while the dissolved inorganic carbon (DIC) and calcium fell as a result of photosynthesis and calcification. Large gradients in pH, water temperature and irradiance were found within the Chara sward and measurements showed that most growth and photosynthesis occurred within the upper 20 cm of the water column. Chara oospore formation was also found to be seasonal but dependent upon environmental conditions.

δ¹⁸O_w rose rapidly during summer as evaporation progressed and this was correlated with the δ¹⁸O_DIC, and to some extent with δ¹⁸O_c of the Chara encrusted calcite. However, extreme isotopic disequilibrium was observed between the δ¹⁸O_c and the δ¹⁸O_w and also between the δ¹³C_c and the δ¹³C_DIC. This arose from the high pH allowing atmospheric CO₂ to enter the water and combine directly with OH⁻.

It is concluded that, within shallow eutrophic lakes containing Chara swards, inferences of climate (e.g. air temperature) cannot be made from observations of the isotopic composition of Chara carbonates. However in combination with other geochemical data, disequilibrium events may be identifiable in ancient lake basins and taken as evidence for lake shallowing and/or eutrophication.     

Influence of DNA repair on mutation spectra in Salmonella

This paper reviews the influence of DNA repair on spontaneous and mutagen-induced mutation spectra at the base-substitution (hisG46) and -1 frameshift (hisD3052) alleles present in strains of the Salmonella (Ames) mutagenicity assay. At the frameshift allele (mostly a CGCGCGCG target), ΔuvrB influences the frequency of spontaneous hotspot mutations (−CG), duplications, and deletions, and it also shifts the sites of deletions and duplications. Cells with pKM101+ΔuvrB spontaneously produce complex frameshifts (frameshifts with an adjacent base substitution). The spontaneous frequency of 1-base insertions or concerted (templated) mutations is unaffected by DNA repair, and neither mutation is inducible by mutagens. Glu-P-1, 1-nitropyrene (1NP), and 2-acetylaminofluorene (2AAF) induce only hotspot mutations and are unaffected by pKM101, whereas benzo(a)pyrene and 4-aminobiphenyl induce only hotspot in pKM101⁻, and hotspot plus complex in pKM101⁺. At the base-substitution allele (mostly a CC/GG target), the ΔuvrB allele increases spontaneous transitions in the absence of pKM101 and increases transversions in its presence. The frequency of suppressor mutations is decreased 4× by ΔuvrB, but increased 7.5× by pKM101. Both repair factors cause a shift in the proportion of mutations to the second position of the CC/GG target. With UV light and γ-rays, the ΔuvrB allele increases the proportion of transitions relative to transversions. pKM101 is required for mutagenesis by Glu-P-1 and 4-AB, and the types and positions of the substitutions are not altered by the addition of the ΔuvrB allele. Changes in DNA repair appear to cause more changes in spontaneous than in mutagen-induced mutation spectra at both alleles. There is a high correlation (r²=0.8) between a mutagen's ability to induce complex frameshifts and its relative base-substitution/frameshift mutagenic potency. A mutagen induces the same primary class of base substitution in TA100 (ΔuvrB, pKM101) as it does in Escherichia coli, mammalian cells, or rodents as well as in the p53 gene of human tumors associated with exposure to that mutagen. Thus, a mutagen induces the same primary class of base substitution in most organisms, reflecting the conserved nature of DNA replication and repair processes.     

One-electron reduction of selenomethionine oxide

Experimental evidence is provided that selenomethionine oxide (MetSeO) is more readily reducible than its sulfur analogue, methionine sulfoxide (MetSO). Pulse radiolysis experiments reveal an efficient reaction of MetSeO with one-electron reductants, such as e^-_aq (k = 1.2 × 10¹⁰M^-1s^-1), CO^·-₂ (k = 5.9 × 10⁸ M^-1s^-1) and (CH₃)₂) C^·OH (k = 3.5 × 10⁷M^-1s^-1), forming an intermediate selenium-nitrogen coupled zwitterionic radical with the positive charge at an intramolecularly formed Se_∴ N 2σ/1σ* three-electron bond, which is characterized by an optical absorption with λ_max at 375 nm, and a half-life of about 70 μs. The same transient is generated upon HO^· radical-induced one-electron oxidation of selenomethionine (MetSe). This radical thus constitutes the redox intermediate between the two oxidation states, MetSeO and MetSe. Time-resolved optical data further indicate sulfur-selenium interactions between the Se_∴ N transient and GSH. The Se_∴ N transient appears to play a key role in the reduction of selenomethionine oxide by glutathione.     

Xenopus axin interacts with glycogen synthase kinase-3 beta and is expressed in the anterior midbrain

Axin is encoded by the fused locus in mice and is required for normal vertebrate axis formation. It has recently been shown that axin associates with the adenomatous polyposis coli gene product (APC), β-catenin and glycogen synthase kinase-3 (GSK-3) in a complex that appears to regulate the level of cytoplasmic β-catenin. We have identified the Xenopus homologue of axin through its interaction with GSK-3β. Xenopus axin (Xaxin) is expressed maternally and throughout early development with a low level of ubiquitous expression. Xaxin also shows remarkably high expression in the anterior mesencephalon adjacent to the forebrain–midbrain boundary.     

长白山阔叶红松林生态系统光能利用率的动态变化及其主控因子

生态系统光能利用率(LUE)反映了植被通过光合作用利用光能吸收和固定大气中CO₂的能力, 是表征生态系统生产力的重要指标。选取长白山温带阔叶红松(Pinus koraiensis)林生态系统为研究对象, 利用涡度相关通量观测数据, 采用直角双曲线方程获取了生态系统光合作用的表观量子效率(ε); 基于总生态系统初级生产力(GEP)与下垫面入射光合有效辐射(Q)的比值得到生态光能利用率(LUE_eco)。研究表明: 在季节尺度上, ε与LUE_eco均表现出显著的单峰变化特征, 并主要受到土壤温度和归一化植被指数(NDVI)的调控, 同时, ε和LUE_eco都受到GEP的显著影响, 而与Q的相关性较弱或无显著相关关系, 但散射辐射的增加在一定程度上有助于提高生态系统的LUE。ε与LUE_eco存在显著的线性正相关关系, 但ε明显高于LUE_eco。2003-2005年, ε与LUE_eco每年最大值的平均值分别为(0.087 ± 0.003)和(0.040 ± 0.002) μmol CO₂·μmol photon^-1, 年际间变异度分别为4.17%和4.25%, 而不同年份之间最大差异均达到8%或8%以上, 从而对模型模拟结果产生明显影响。因此, 在基于光能利用率模型的模拟研究中, 最大LUE的年际变异需要在参数反演和优化中给予重要考虑。     

利用叶绿素荧光评估草原植物羊草缺磷缺氮状况

羊草(Leymus chinensis)是北方草原的重要牧草。准确评估其营养状况,对维护羊草草原的生产力具有重要意义。以羊草幼苗为材料,利用能同时表征2个光系统光化学活性的叶绿素荧光检测技术,对缺氮和缺磷处理下的叶片光化学活性进行分析。结果表明,缺氮处理20天后羊草叶片叶绿素含量降低近50%。同期缺磷及缺氮处理对PSⅡ功能的影响总体大于PSⅠ。与对照相比,缺氮叶片的Φ(Ⅱ)和Φ(Ⅰ)分别比对照降低了30.3%与38.5%;ETR(Ⅱ)与ETR(Ⅰ)分别降低30.8%和28.9%。缺磷处理组Φ(Ⅱ)和ETR(Ⅱ)的降低幅度约为缺氮的1/2。这些定量研究结果对及时有效地诊断和区分羊草植物氮磷缺乏状况具有重要的参考价值。     

Dynamics and regulations of ecosystem light use efficiency in a broad-leaved Korean pine mixed forest,Changbai Mountain

Aims Ecosystem light use efficiency (LUE) reflects the ability of CO₂ uptake and light utilization via photosynthesis, which is a key parameter in ecosystem models to evaluate ecosystem productivity. The objectives of this study were to: (1) compare the differences of LUE derived from different methods; (2) elucidate the seasonal dynamics of LUE and its regulatory factors; and (3) evaluate the maximum LUE (LUE_max) and its variability based on eddy-covariance (EC) flux.Methods Using the flux data from an EC tower during 2003-2005 at a broad-leaved Korean pine (Pinus koraiensis) mixed forest, Changbai Mountain, two types of LUE indicators were generated from: 1) the apparent quantum yield (ε) estimated with rectangular hyperbolic curve, and 2) the ecological light use efficiency (LUE_eco) calculated as the ratio between gross ecosystem productivity (GEP) and photosynthetically-active radiation (Q).Important findings The seasonal variation of ε and LUE_eco appeared a unimodal pattern within a year, with the variations significantly dominated by soil surface temperature and Normalized Difference Vegetation Index (NDVI). A positive correlation between GEP and LUE was found for both ε and LUE_eco, with the effect of Q on LUE relatively weak. The increase in diffusion radiation appeared favorable for enhanced LUE. Generally, there was a significant positive relationship between ε and LUE_eco, while ε was higher than LUE_eco, especially during the mid-season. The annual maximum value of ε and LUE_eco was (0.087 ± 0.003) and (0.040 ± 0.002) μmol CO₂·μmol photon^-1 over the three years, respectively. The interannual variability of LUE_max for ε and LUE_eco was 4.17% and 4.25%, respectively, with a maximum difference of >8%, likely resulted from considerable uncertainty in model simulations. Our results indicated that the inversion and optimization of maximum LUE should be taken seriously in the application of LUE models.