Societal Impact Statement
Confronting the ongoing biodiversity crisis and our incomplete taxonomic knowledge on the world's plants requires well‐trained experts able to recognize and identify ...species. Although botanical training is an integral part of many university programs in biology, plant identification skills are becoming rare. The Covid‐19 pandemic has challenged plant identification classes as many courses rely on hands‐on practicing with plant material or guided excursions. Here, we present BotanizeR, a flexible online tool to make the wealth of digitally available but scattered information on plant characteristics accessible and allow users to practice plant identification. BotanizeR can assist in teaching plant knowledge in a playful way during times of online teaching and beyond and may help to increase the fascination of biology students and laypeople alike for plant diversity.
Confronting the ongoing biodiversity crisis and our incomplete taxonomic knowledge on the world's plants requires well‐trained experts able to recognize and identify species. Although botanical training is an integral part of many university programs in biology, plant identification skills are becoming rare. The Covid‐19 pandemic has challenged plant identification classes as many courses rely on hands‐on practicing with plant material or guided excursions. Here, we present BotanizeR, a flexible online tool to make the wealth of digitally available but scattered information on plant characteristics accessible and allow users to practice plant identification. BotanizeR can assist in teaching plant knowledge in a playful way during times of online teaching and beyond and may help to increase the fascination of biology students and laypeople alike for plant diversity.
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•Compared ALS, TLS, and ground data in 52 tree islands in an oil palm landscape in Sumatra.•ALS and TLS similarly capture canopy gaps and tree height metrics.•LiDAR complements ground ...data, enhancing 3D vegetation structural characterization.
Vegetation structural complexity is an important component of forest ecosystems, influencing biodiversity and functioning. Due to the heterogeneous distribution of vegetation elements, structural complexity underpins ecological dynamics, species composition, microclimate, and habitat diversity. Field measurements and Light Detection and Ranging (LiDAR) data, such as airborne (ALS) and terrestrial (TLS), can assess structural characteristics of forest and agroforestry systems at various spatial scales. This assessment is urgently needed for monitoring ecosystem restoration in degraded lands (e.g., in oil palm landscapes), where it is not well-known how structural measures derived from these different approaches relate to each other. Here, we compared the degree of correlation between individual and multivariate datasets of vegetation structural complexity metrics derived from ALS, TLS, and ground-based inventory approaches. The study was conducted in a 140 ha oil palm monoculture, enriched with 52 plots in the form of tree islands representing agroforestry systems of varying sizes and planted diversity levels in Sumatra, Indonesia. Our datasets comprised 25 ALS, five TLS, and nine ground-based inventory metrics. We studied correlations among metrics related to traditional stand summary, heterogeneity, and vertical and horizontal stand structure. We used principal component analysis for data dimensionality reduction, correlation analysis to quantify the strength of relationships between metrics, and Procrustes analysis to investigate the agreement between datasets. Significant correlations were found between ALS and TLS metrics for canopy density (r = 0.79) and maximum tree height (r = 0.58) and between ALS and ground-based inventory measures of stand heterogeneity and height diversity (r between 0.60 and −0.63). Further, we observed significant agreements between the ordinations of multivariate datasets (r = 0.56 for ALS − TLS; and r = 0.46 for ALS – ground-based inventory). Our findings underline the ability of ALS to capture structural complexity patterns, especially for canopy gap dynamics and vegetation height metrics, as captured by TLS, and for measures of heterogeneity and vertical structure as captured by ground-based inventories. Our study highlights the strength of each approach and underscores the potential of integrating ALS and TLS with ground-based inventories for a comprehensive characterization of vegetation structure in complex agroforestry systems, which can provide guidance for their management and support ecosystem restoration monitoring efforts.
Most plant-available Si in strongly desilicated soils is provided through litter decomposition and subsequent phytolith dissolution. The
importance of silicon (Si) cycling in tropical soil–plant ...systems raised the question of whether oil-palm (Elaeis guineensis Jacq.) cultivation alters Si cycling. As oil palms are considered Si hyper-accumulators, we hypothesized that much Si is stored in the
above-ground biomass of oil palms with time. Furthermore, the system might lose considerable amounts of Si every year through fruit-bunch harvest. To
test these hypotheses, we analysed Si concentrations in fruit-bunch stalks,
fruit pulp and kernels, leaflets, rachises, and frond bases of mature oil palms on eight smallholder oil-palm plantations in Sumatra,
Indonesia. We estimated Si storage in the total above-ground biomass of oil palms, Si return to soils through decomposing pruned palm fronds, and Si
losses from the system through harvest. Leaflets of oil-palm fronds had a
mean Si concentration of > 1 wt %. All other analysed plant parts had < 0.5 wt % Si. According to our estimates, a single
palm tree stored about 4–5 kg Si in its total above-ground biomass. A smallholder oil-palm plantation stored at least 550 kg Si ha−1 in the
palm trees' above-ground biomass. Pruned palm fronds returned 111–131 kg of Si ha−1 to topsoils each year. Fruit-bunch harvest corresponded to
an annual Si export of 32–72 kg Si ha−1 in 2015 and 2018. Greater
Si losses (of at least 550 kg Si ha−1) would occur from the system if
oil-palm stems were removed from plantations prior to replanting. Therefore,
it is advisable to leave oil-palm stems on the plantations, e.g. by distributing chipped stem parts across the plantation at the end of a
plantation cycle (∼ 25 years).
Experiments performed with a voltage generator giving one pulse with an exponential decay showed that the transformation efficiency in dependence on the current density had a clear shift of the ...transformation maximum according to the conductivity of the bacteria suspension for Escherichia coli C600 as well as for Bacillus subtilis 168. For higher conductivities, higher current densities are needed to reach the transformation maximum.
In this study a square wave generator was applied. It was explicitly shown, that electroporation of E. coli depends only indirectly on the current density. In fact, the key parameter is the amount of charges applied to the bacteria. During the measurements with the square wave generator an extraordinary behavior of the current pulses could be observed which leads to the following assumptions: During the electroporation process there is not only a direct current but also a dielectric coupled current in form of a displacement current taking place within the cuvette.
•Electroporation of E. coli depends only indirectly on the current density.•Applying a square wave generator an extraordinary behavior of the current pulses could be observed.•Not only a direct current but also a dielectric coupled current in form of a displacement current appears.
Oil palm plantations are intensively managed agricultural systems that increasingly dominate certain tropical regions. Oil palm monocultures have been criticized because of their reduced biodiversity ...compared to the forests they historically replaced, and because of their negative impact on soils, water, and climate. We experimentally test whether less intensive management schemes may enhance biodiversity and lessen detrimental effects on the environment while maintaining high yields. We compare reduced vs. conventional fertilization, as well as mechanical vs. chemical weed control (with herbicides) in a long-term, full-factorial, multidisciplinary experiment. We conducted the experiment in an oil palm company estate in Sumatra, Indonesia, and report the results of the first 2 years. We measured soil nutrients and functions, surveyed above- and below-ground organisms, tracked oil palm condition and productivity, and calculated plantation gross margins. Plants, aboveground arthropods, and belowground animals were positively affected by mechanical vs. chemical weed control, but we could not detect effects on birds and bats. There were no detectable negative effects of reduced fertilization or mechanical weeding on oil palm yields, fine roots, or leaf area index. Also, we could not detect detrimental effects of the reduced fertilization and mechanical weeding on soil nutrients and functions (mineral nitrogen, bulk density, and litter decomposition), but water infiltration and base saturation tended to be higher under mechanical weeding, while soil moisture, and microbial biomass varied with treatment. Economic performance, measured as gross margins, was higher under reduced fertilization. There might be a delayed response of oil palm to the different management schemes applied, so results of future years may confirm whether this is a sustainable management strategy. Nevertheless, the initial effects of the experiment are encouraging to consider less intensive management practices as economically and ecologically viable options for oil palm plantations.
•Detailed tree inventory and transect study in a little-known region of Wallacea.•Surprisingly high tree species endemism in Sulawesi.•Alpha tree diversity not lower than in other Malesian ...regions.•Understorey tree species contribute disproportionally to species diversity.
Explaining the diversity and distribution of tree taxa in the isolated tropical mountain forests (TMF) of the Malesian archipelago remains one of the great challenges of tropical biogeographical research. We investigated tree diversity, endemism and community composition in 13 plots of 0.24ha between 700 and 2400m in the TMF of Central Sulawesi’s (Indonesia) highlands and related the patterns to gradients in elevation, climate and soil properties. Special attention was paid to understorey trees with stem diameters as low as 2cm, not exceeding 2/3 of stand canopy height. Based on extensive taxonomic work on the plots, we found that Sulawesi’s TMF flora is with 27–78 species per 0.24ha not species-poorer than that of other Malesian islands, and vascular plant endemism is higher (22% of the species endemic to Sulawesi) than previously thought. Alpha diversity was mainly dependent on elevation and not soil factors (7 parameters tested). The alpha diversity of tree species, genera and families declined linearly with elevation, as did the number of species and genera per family, revealing higher phylogenetic clustering at lower elevations. Indicator Species Analysis and cluster analysis identified three main forest belts (sub-montane at c. 700–1400m, lower montane at c. 1400–2000m, upper montane at >c. 2000m), deviating from earlier zonation concepts by separating sub-montane (rich in taxa related to the lowlands) and lower montane communities (rich in Fagaceae and Myrtaceae). With 27–51% of all tree species in a plot never found in the upper canopy, our data suggest that the guild of true understorey tree species is species-rich (estimated at c. 130 species in our region), contradicting the hypothesis that Southeast Asian tropical forests with mass-flowering trees (here: Fagaceae) are particularly poor in understorey tree species. We conclude that the mountains of Sulawesi harbour remarkably species-rich, but still understudied, TMF with a unique tree flora rich in understorey trees, which are of high conservation priority.
Vegetation structural complexity has been identified as a vital factor for forest ecosystem function, stability, and resilience. However, agricultural land with much reduced structural complexity has ...largely replaced natural forests in the tropics. Therefore, restoring structural complexity in large-scale plantation monocultures by introducing agroforestry systems may counteract the loss of biodiversity and ecosystem functions. However, we still have limited knowledge of how the structural complexity of agroforests develops under different restoration treatments. We established a large-scale biodiversity enrichment experiment in a conventional monoculture oil palm plantation in Sumatra, Indonesia. In this experiment, agroforests were implemented by planting clusters of native trees (“tree islands”) within the oil palm plantation, systematically varying initially planted tree richness ranging from 0–6 (0 corresponding to natural regeneration only) and plot area (25–1600 m2). We tested the effect of the experimental treatments on nine years of the development of local structural complexity using a stand structural complexity index (SSCI) derived from terrestrial laser scanning. We found that tree planting and natural regeneration treatments promoted structural complexity by creating denser and more complex vegetation structures. Plots with a tree planting treatment tended to show greater structural complexity than plots with natural regeneration only. However, during the study period, oil palms still dominated heights, and the temporal change in structural complexity among plots with or without a tree planting treatment did not differ. As for plot area, our results indicate that structural complexity looking from the center of plots did not necessarily depend on the area during the study period, and even small tree islands can increase local structural complexity in a monoculture oil palm plantation. Initially planted tree richness did not significantly affect the development of structural complexity. Nine years after establishment, not planted trees but regenerated woody plants strongly positively affected vegetation density and structural complexity. Our findings highlight that sustaining vegetation density below oil palm canopies is a key strategy to increase the structural complexity of oil palm landscapes.
•Analyzed the long-term structural complexity of experimental oil palm agroforests.•Combining planting trees and natural regeneration promoted structural complexity.•Initially planted tree richness and plot area did not affect structural complexity.•Regenerated woody plants drove structural complexity nine years after establishment.•Sustaining vegetation density below oil palm canopy promotes structural complexity.
Transformation and surviving of E. coli C600 have been evaluated in dependence on the electric field strength and current density by changing the conductivity of the bacteria suspension. In this ...context the impact of making bacteria electrocompetent and the addition of NaCl solution was examined.
Transformation efficiency declines with increasing conductivity of the suspension. When washing bacteria differently, the transformation efficiency correlates with the number of survivors. In contrary, adding different concentrations of NaCl has no effect on the surviving of E. coli C600.
In dependence on the electric field strength, the transformation efficiency shows no effect on changing the conductivity. Regarding the transformation efficiency in dependence of the current density, a clear shift of the transformation maximum was observed. For higher conductivities, higher current densities are needed to reach the transformation maximum.
•Current density and conductivity of the bacteria suspension are determined.•Measurement of current density and conductivity are performed before and after electroporation.•A developed calibration ...function serves to determine a small range for optimum electric field.•Optimum electroporation can be received with much less attempts.
Transformation of Escherichia coli C600 and Bacillus subtilis 168 have been evaluated in dependence on the electric field and current density by changing the conductivity of the bacteria suspension. For both kinds of bacteria, E. coli C600 and B. subtilis 168, the trans-formation efficiency in dependence on the current density showed a clear shift of the transformation maximum according to the conductivity of the bacteria suspension. For higher conductivities, higher current densities are needed to reach the transformation maximum. Based on the measured conductivity of the bacteria suspension before and during the electroporation process a diagram was developed, which can be used to predict the electric field. It has to be applied for maximal transformation efficiencies of E. coli C600 with pDsRed-Express plasmid DNA (3311 base pairs), when using a voltage generator with an exponential decay (decay time: τ=3ms). This means, a transformation mixture of unknown composition (except for the kind of cells and nucleic acid) can be measured for its conductivity in the first place and treated with the resulting voltage. Experiments showed, that a similar calibration graphic could be developed for B. subtilis 168 with pBluescript KS II (+) (2961 base pairs).
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