To develop a finescale dataset for the purpose of analyzing historical climatic change over the Tibet Plateau (TP), a high-resolution regional climate simulation for 1979–2011 was conducted using the ...Weather Research and Forecasting (WRF) Model driven by the ERA-Interim (ERA-Int). This work evaluates the high-resolution (30 km) WRF simulation in terms of annual variation, spatial structure, and 33-yr temporal trends of surface air temperature (Tair) and precipitation (Prec) over the TP, with reference to station observations. Another focus is on the examination of the height–temperature relationship. Inheriting from its forcing, the WRF simulation presents an apparent cold bias in the TP. The cold bias is largely reduced by a lapse rate correction of the simulated surface air temperature with help of the station and model elevations. ERA-Int presents the same sign of Tair and Prec trends as the observations, but with smaller magnitude, especially in the dry season. Compared to its forcing, the WRF simulation improves the simulation of the annual cycles and temporal trends of Tair and Prec in the wet season. In the dry season, however, there is hardly any improvement. The observed Tair presents a downward linear trend in the lapse rate. This feature is examined in the WRF simulation in comparison to ERA-Int. The WRF simulation captures the observed lapse rate and its temporal trend better than ERA-Int. The decreasing lapse rate over time confirms that Tair change in the TP is elevation dependent.
The investigation was conducted during the year 2011-2013 with the objectives of studying the influence of INM practices comprised of organic inorganic and biofertilizer on dry matter of different ...parts and nutrient uptake in African marigold cv. Sirakole in three seasons. The experiment was laid out in Randomized Block Design which consisted of 15 treatments, each replicated thrice during Kharif, Rabi and Summer season. The results of the study revealed that various nutrient management practices had significant influence on nutrient uptake characters in all three seasons. Nitrogen, phosphorus and potash uptake was highest in the plants supplied with 25% organic and 75% inorganic fertilizer along with biofertilizers in rabi season. Pooled over the seasons indicated that plants receiving nutrient combination of poultrymanure (25%RDN)+ 75% RD‛NPʼ+biofertilizers exhibited highest nutrient uptake in rabi season.
Lianas exhibit peak abundance in tropical forests with strong seasonal droughts, the eco‐physiological mechanisms associated with lianas coping with water deficits are poorly understood. We examined ...soil water partitioning, sap flow, and canopy eco‐physiological properties for 99 individuals of 15 liana and 34 co‐occurring tree species in three tropical forests that differed in soil water availability. In the dry season, lianas used a higher proportion of deep soil water in the karst forest (KF; an area with severe seasonal soil water deficit (SSWD)) and in the tropical seasonal forest (TSF, moderate SSWD), permitting them to maintain a comparable leaf water status than trees in the TSF or a better status than trees in the KF. Lianas exhibited strong stomatal control to maximize carbon fixation while minimizing dry season water loss. During the dry period, lianas significantly decreased water consumption in the TSF and the KF. Additionally, lianas had a much higher maximum photosynthetic rates and sap flux density in the wet season and a lower proportional decline in photosynthesis in the dry season compared with those of trees. Our results indicated that access to deep soil water and strong physiological adjustments in the dry season together with active wet‐season photosynthesis may explain the high abundance of lianas in seasonally dry forests.
Most ecosystems have multiple predator species that not only compete for shared prey, but also pose direct threats to each other. These intraguild interactions are key drivers of carnivore community ...structure, with ecosystem‐wide cascading effects. Yet, behavioral mechanisms for coexistence of multiple carnivore species remain poorly understood. The challenges of studying large, free‐ranging carnivores have resulted in mainly coarse‐scale examination of behavioral strategies without information about all interacting competitors. We overcame some of these challenges by examining the concurrent fine‐scale movement decisions of almost all individuals of four large mammalian carnivore species in a closed terrestrial system. We found that the intensity of intraguild interactions did not follow a simple hierarchical allometric pattern, because spatial and behavioral tactics of subordinate species changed with threat and resource levels across seasons. Lions (Panthera leo) were generally unrestricted and anchored themselves in areas rich in not only their principal prey, but also, during periods of resource limitation (dry season), rich in the main prey for other carnivores. Because of this, the greatest cost (potential intraguild predation) for subordinate carnivores was spatially coupled with the highest potential benefit of resource acquisition (prey‐rich areas), especially in the dry season. Leopard (P. pardus) and cheetah (Acinonyx jubatus) overlapped with the home range of lions but minimized their risk using fine‐scaled avoidance behaviors and restricted resource acquisition tactics. The cost of intraguild competition was most apparent for cheetahs, especially during the wet season, as areas with energetically rewarding large prey (wildebeest) were avoided when they overlapped highly with the activity areas of lions. Contrary to expectation, the smallest species (African wild dog, Lycaon pictus) did not avoid only lions, but also used multiple tactics to minimize encountering all other competitors. Intraguild competition thus forced wild dogs into areas with the lowest resource availability year round. Coexistence of multiple carnivore species has typically been explained by dietary niche separation, but our multi‐scaled movement results suggest that differences in resource acquisition may instead be a consequence of avoiding intraguild competition. We generate a more realistic representation of hierarchical behavioral interactions that may ultimately drive spatially explicit trophic structures of multi‐predator communities.
Despite growing interest in trait-based approaches to community assembly, little attention has been given to seasonal variation in trait distribution patterns. Mobile animals can rapidly mediate ...influences of environmental factors and species interactions through dispersal, suggesting that the relative importance of different assembly mechanisms can vary over short time scales. This study analyzes seasonal changes in functional trait distributions of tropical fishes in the Xingu River, a major tributary of the Amazon with large predictable temporal variation in hydrologie conditions and species density. Comparison of observed functional diversity revealed that species within wet-season assemblages were more functionally similar than those in dry-season assemblages. Further, species within wet-season assemblages were more similar than random expectations based on null model predictions. Higher functional richness within dry season communities is consistent with increased niche complementarity during the period when fish densities are highest and biotic interactions should be stronger; however, null model tests suggest that stochastic factors or a combination of assembly mechanisms influence dry-season assemblages. These results demonstrate that the relative influence of community assembly mechanisms can vary seasonally in response to changing abiotic conditions, and suggest that studies attempting to infer a single dominant mechanism from functional patterns may overlook important aspects of the assembly process. During the prolonged flood pulse of the wet season, expanded habitat and lower densities of aquatic organisms likely reduce the influence of competition and prédation. This temporal shift in the influence of different assembly mechanisms, rather than any single mechanism, may play a large role in maintaining the structure and diversity of tropical rivers and perhaps other dynamic and biodiverse systems.
By using stable isotope techniques, the Platycladus orientalis grown on the rocky hilly area of North China were chosen to investigate air temperature, soil temperature, moisture and δD value in ...order to discuss the effect of seasonal rainfall on soil temperature, moisture and water movement. The results indicated that: the soil temperature following rainfal decreased first and then increased in the rainy season, and decreased with the increases of depths, whereas in the early dry season the temperature continued to decrease but increased with the depth. No matter in the rain or dry season, the soil moisture increased at first and then decreased after the rain, but dropped with the depth of soil. In rain season, when the early soil moisture was low, the low intensity rainfall could further increase the moisture of surface and deep soil and made the water δD value deplete, which showed rainfall could recharge the surface and middle soil. However, in prior plentiful rainfall period, low intensity rainfall could
BackgroundIn the U.S. National Football League (NFL), approximately 1 in 4 players sustains a lower extremity (LEX) strain each season. Nearly 20% occur in the ~2-week period of Training Camp at the ...start of preseason, and LEX strains have a high rate of recurrence.ObjectiveExamine Training Camp practice schedule strategies associated with LEX strain incidence, identify and implement an actionable reduction strategy, and evaluate effectiveness.DesignObservational study comparing LEX strain incidence by practice schedule strategy using wearable player tracking data linked to Club schedule.Setting32 NFL ClubsPatientsAll NFL players participating during 2018–2022InterventionsData from the league-wide electronic health record were combined with player tracking data. Individual Club practice patterns were analyzed and described, then grouped into strategies. Results were communicated to stakeholders in 2021–2022, and in 2022, a league-wide gradual 15-minute ramp-up was implemented mandating maximum practice durations coupled with individual Club education sessions (Figure 1).Abstract 882 Figure 1Preseason practice strategiesAbstract 882 Figure 2Training camp lower extremity strains.Main Outcome MeasuresStrains to the hamstring, quadriceps, adductor, and calf were identified. Incidence rates per 100 practice-minutes and 95% confidence intervals during and following Training Camp were calculated.ResultsFrom 2018–2021, 5 distinct practice schedule strategies were identified from 82 Club-seasons: gradual 15-minute ramp-up, <10-minute ramp-up, high-low duration variation, stable duration, and reverse ramp-up (Figure 1). Clubs utilizing the gradual 15-minute ramp-up strategy had lower LEX strain rates and Clubs utilizing the reverse ramp-up strategy had higher LEX strain rates during Training Camp compared to the other strategies (Table 1). Following the intervention, league-wide LEX strain incidence during Training Camp decreased by 25% from 286 in 2021 to 215 in 2022 (Figure 2). Recurrent LEX strains in 2022 regular season decreased by 50% (n=11 vs. n=22).ConclusionA mandated gradual ramp-up coupled with education at the beginning of preseason successfully reduced LEX strains in the NFL.Abstract 882 Table 1Training Camp LEX strain rate per 100 practice-minutes and 95% confidence interval by Club-season practice strategy, 2018–2021 Gradual 15-minute ramp-up <10-minute ramp-up High-low duration variation Stable duration Reverse ramp-up Unique Clubs 14 17 9 13 6 Club Seasons 15 27 13 18 9 Injury Rate per 100 Practice-Minutes and 95% CI 0.41 (0.34, 0.51) 0.44 (0.38, 0.51) 0.45 (0.37, 0.55) 0.55 (0.47, 0.65) 0.57 (0.45, 0.72)
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