<b>Enhanced rock weather</b><b>ing</b><b> </b><b>increased soil phosphorus availability and altered</b><b> </b><b>root phosphorus acquisition strategies</b>

Enhanced rock weathering (ERW) measures are considered for CO2 removal with potential for additional organic C sequestration potential (Beerling et al., 2020; Goll et al., 2021). The effects of this practice on the soil phosphorus (P) pools and the general mechanisms affecting microbial P cycling, as well as plant P uptake are not well understood. Here, the impact of ERW on soil P availability and root P-acquisition traits were explored through a two-year wollastonite field addition experiment in a tropical rubber plantation.</p

<b>Enhanced ro</b><b>ck</b><b> weather</b><b>ing</b><b> </b><b>increased soil phosphorus availability and altered</b><b> </b><b>root phosphorus-acquisition strategies</b>

Enhanced rock weathering (ERW) measures are considered for CO2 removal with potential for additional organic C sequestration potential (Beerling et al., 2020; Goll et al., 2021). The effects of this practice on the soil phosphorus (P) pools and the general mechanisms affecting microbial P cycling, as well as plant P uptake are not well understood. Here, the impact of ERW on soil P availability and root P-acquisition traits were explored through a two-year wollastonite field addition experiment in a tropical rubber plantation.</p

Root phosphatase activity is a competitive trait affiliated with the conservation gradient in root economic space

Background: The diversity of resource acquisition strategies of plant roots determines the species coexistence patterns to a certain extent. However, few root physiological traits have been investigated, such as root phosphatase activity (PA) that affects plant phosphorus (P) uptake. Methods: Root PA and classical root functional traits were investigated for 21 coexisting species in a deciduous broad-leaved forest in warm temperate-subtropical transition zone, China. We analyzed the root order variation of absorptive fine root PA, clarified the attribution of root PA in root economic space (RES) and the different P acquisition strategies of co-occurring species based on the multidimensional RES theory, and determined the dominant factors affecting interspecific variation in root PA. Results: There was no distinct pattern of PA variation with root order in the first three root orders of absorptive fine roots, and root PA was constrained by phylogeny. Root PA is a competitive trait affiliated with the conservation gradient in RES. The tight linkages among root PA, mycorrhizal colonization, diameter, specific root length, and nitrogen concentration suggested trade-offs among P acquisition strategies of co-occurring species, i.e. species with long and fine roots acquire inorganic P by actively exploring the soil and secreting phosphatase to mineralize and hydrolyze organic P, while species with short and thick roots obtain P mainly by investing C in mycorrhizal partners. Conclusions: Collectively, our study provides an insight into the forest species coexistence in climatic transition zones, i.e. species coexistence mechanisms based on diverse phosphorus acquisition strategies

MK-Pad: a mouse+keyboard input technique for distance interaction through a mobile tablet device

We introduce MK-Pad (Mouse+Keyboard Pad), a technique for entering text and performing mouse operations using a tablet device for distance interaction. MK-Pad uses the screen of a 10.1" tablet touchscreen to host a soft keyboard and turns the screen into a large multi-touch trackpad. The multi-touch capabilities of the tablet make it possible to avoid the need for explicit mode switching between textentry and mouse operations. Similarly, because of the relatively large size of the tablet display, we are able to map the entire external screen onto the tablet display and this provides users with both absolute and relative cursor positioning: tapping causes the cursor to jump to the corresponding location, providing rapid movement across large distances, while clutching using relative mode supports fine positioning control. We conducted two studies. We use data from the first study to inform the design of MK-Pad. In the second study we compare MKPad against the standard mouse and keyboard. The results show that MK-Pad has potential and a good alternative to mouse and keyboard for distance interaction with large displays

Probing diffusive phase transition in Ba(Ti

Ba(Ti0.80 Zr0.20)O3-0.5(Ba0.70 Ca0.30)TiO3 (BTZ-0.5BCT) nanofibers (NFs) demonstrated diffusive phase transition, resulting in an enhanced Curie temperature TC. As a result, it is scientific significant to probe the variation of ferro/piezoelectricity during such diffusive phase transition region. In this letter, the ferro/piezoelectricity of BTZ-0.5BCT NF was probed by piezoelectric force microscopy (PFM) under a series of temperatures revealing the piezoresponse of BTZ-0.5BCT NF increased with temperatures as the temperature is less than 180°C. The result shows that the first harmonic piezoresponse initially increased with temperatures, yet two singularities appeared at 120 and 180°C, and subsequently rapidly decreased to less than room temperature, demonstrating the corresponding ferroelectric transition process was a diffusive phase transition. Such a diffusive phase transition is caused by the discontinuous internal nanostructure of the NF and the size effect of ferro/piezoelectricity originated from the nano-ceramics. More importantly, the principal ferroelectric phase transition of nano-ceramics during such diffusive phase transition region was further quantified by principal component analysis (PCA) study. This indicates that the principal TC of BTZ-0.5BCT nano-ceramics is around 180°C, representing the TC of the whole BTZ-0.5BCT NF. Such a vivid description of the variated ferro/piezoelectricity with temperatures allows to provide a scientific method to quantify diffusive phase transition by PCA study

Enhanced rock weathering increased soil phosphorus availability and altered root phosphorus‐acquisition strategies

International audienceAbstract Enhanced rock weathering (ERW) has been proposed as a measure to enhance the carbon (C)‐sequestration potential and fertility of soils. The effects of this practice on the soil phosphorus (P) pools and the general mechanisms affecting microbial P cycling, as well as plant P uptake are not well understood. Here, the impact of ERW on soil P availability and microbial P cycling functional groups and root P‐acquisition traits were explored through a 2‐year wollastonite field addition experiment in a tropical rubber plantation. The results show that ERW significantly increased soil microbial carbon‐use efficiency and total P concentrations and indirectly increased soil P availability by enhancing organic P mobilization and mineralization of rhizosheath carboxylates and phosphatase, respectively. Also, ERW stimulated the activities of P‐solubilizing ( gcd , ppa and ppx ) and mineralizing enzymes ( phoADN and phnAPHLFXIM ), thus contributing to the inorganic P solubilization and organic P mineralization. Accompanying the increase in soil P availability, the P‐acquisition strategy of the rubber fine roots changed from do‐it‐yourself acquisition by roots to dependence on mycorrhizal collaboration and the release of root exudates. In addition, the direct effects of ERW on root P‐acquisition traits (such as root diameter, specific root length, and mycorrhizal colonization rate) may also be related to changes in the pattern of belowground carbon investments in plants. Our study provides a new insight that ERW increases carbon‐sequestration potential and P availability in tropical forests and profoundly affects belowground plant resource‐use strategies

Enhanced silicate weathering accelerates forest carbon sequestration by stimulating the soil mineral carbon pump

International audienceAbstract Enhanced silicate rock weathering (ERW) is an emerging strategy for carbon dioxide removal (CDR) from the atmosphere to mitigate anthropogenic climate change. ERW aims at promoting soil inorganic carbon sequestration by accelerating geochemical weathering processes. Theoretically, ERW may also impact soil organic carbon (SOC), the largest carbon pool in terrestrial ecosystems, but experimental evidence for this is largely lacking. Here, we conducted a 2‐year field experiment in tropical rubber plantations in the southeast of China to evaluate the effects of wollastonite powder additions (0, 0.25, and 0.5 kg m −2 ) on both soil organic and inorganic carbon at 0–10 cm depth. We found that ERW significantly increased the concentration of SOC and HCO 3 − , but the increases in SOC were four and eight times higher than that of HCO 3 − with low‐ and high‐level wollastonite applications. ERW had positive effects on the accrual of organic carbon in mineral‐associated organic matter (MAOM) and macroaggregate fractions, but not on particulate organic matter. Path analysis suggested that ERW increased MAOM mainly by increasing the release of Ca, Si, and Fe, and to a lesser extent by stimulating root growth and microbial‐derived carbon inputs. Our study indicates that ERW with wollastonite can promote SOC sequestration in stable MOAM in surface soils through both the soil mineral carbon pump and microbial carbon pump. These effects may have been larger than the inorganic CDR during our experiment. We argue it is essential to account for the responses of SOC in the assessments of CDR by ERW