Negative resistance and resilience: biotic mechanisms underpin delayed biological recovery in stream restoration

Traditionally, resistance and resilience are associated with good ecological health, often underpinning restoration goals. However, degraded ecosystems can also be highly resistant and resilient, making restoration difficult: degraded communities often become dominated by hyper-tolerant species, preventing recolonization and resulting in low biodiversity and poor eco-system function. Using streams as a model, we undertook a mesocosm experiment to test if degraded community presence hindered biological recovery. We established 12 mesocosms, simulating physically healthy streams. Degraded invertebrate communities were established in half, mimicking the post-restoration scenario of physical recovery without biological recovery. We then introduced a healthy colonist community to all mesocosms, testing if degraded community presence influenced healthy community establishment. Colonists established less readily in degraded community mesocosms, with larger decreases in abundance of sensitive taxa, likely driven by biotic interactions rather than abiotic constraints. Resource depletion by the degraded community likely increased competition, driving priority effects. Colonists left by drifting, but also by accelerating development, reducing time to emergence but sacrificing larger body size. Since degraded community presence prevented colonist establishment, our experiment suggests successful restoration must address both abiotic and biotic factors, especially those that reinforce the ‘negative’ resistance and resilience which perpetuate degraded communities and are typically overlooke

Normal Seedlings as a New Parameter for Predicting Cross-Incompatibility Level on Sweetpotato

This research aimed to investigate the incompatibility levels of controlled cross-pollination in sweetpotato, based on normal seedling percentage and their correlation with seed vigour. The controlled cross-pollination in sweetpotato faces issues due to its cross-incompatibility and self-incompatibility characteristics. Currently, the incompatibility level in sweetpotato is investigated based on the fruit set percentage. However, this criterion lacks the ability in accurately predicting the number of new clones. Therefore, it is essential to study new parameters to create a better investigation of incompatibility in sweetpotato. The materials used in this research consisted of eight sweetpotato clones as female and four sweetpotato clones as male parents. Cross-pollinations were done reciprocally. The experiment was conducted at Indonesian Legume and Tuber Crops Research Institute from April to December 2014. The result showed that totally 5,188 times crossing produced about 25% fruit sets and 10% normal seedlings. The use of normal seedlings percentage as a new parameter in evaluating cross-pollination has apparently seemed to be more effective than the fruit sets percentage method because numbers of new clones could be known accurately. This research revealed that the normal seedling could be used as a new parameter in determining the incompatibility level in sweetpotato controlled cross-pollination

The Relationship of Sweet Potato Germplasm Based on Morphological Characters

Information about the morphological and genetic characteristics of sweet potato (Ipomoea batatas) is important in the variety development program. This experiment aimed to determine the diversity and genetic relationship of sweet potato accessions from NTT based on morphological character data. The research was carried out at Kendalpayak Research Station, Malang, East Java from April - September 2019. The materials used were seventy-one sweet potato germplasm from the ILETRI collection (collected from NTT). Each accession was planted on a 1 m × 5 m plot size, with a spacing of 100 × 20 cm (single row). Fertilization was carried out using a dose of “100 kg urea + 100 kg SP36 + 200 kg KCl ha-1”. The observed characters were the vines length, growth type, internode length, leaf length, leaf width, leaf size, leaf bone color, leaf shape, leaf characteristics, lobes number, lobe shape, mature leaf color, shoot color, pigmentation of petiole, young stems pigmentation (dominant and secondary color), young leaves feathers, tuber skin color, tuber flesh color, weight of canopy, number of tubers perplot, weight of tubers perplot, number and weight of tubers perplot. Cluster analysis was carried out using the Minitab 17 program. There was morphological diversity in seventy-one accessions of sweet potato germplasm from NTT. Principal component analysis resulted in seven main components with the proportion of diversity 76.3%. cluster analysis, seventy-one accessions of sweet potato germplasm were divided into fifteen accession groups on the basis of 80% degree. Characteristics of shoot color, mature leaf color, leaf size, petiole pigmentation, and leaf bone color contributed greatly to the total diversity

Factors Related to Diagnosis of Community-Acquired Pneumonia in the Elderly

Introduction. Diagnosing community-acquired pneumonia (CAP) in the elderly remains a clinical challenge for various reasons. The clinical manifestation in the elderly is not frank and atypical manifestations, e.g. falls, decrease of functional status and food intake or urinary incontinence, may be present. These reasons may be associated with under or over diagnosis, which consequently contribute to the higher observed mortality rate in the elderly population with CAP. Study about factors related to diagnosis of CAP in the elderly was ra rely performed. Methods. From January to October 2010, 158 elderly patients suspected of having pneumonia at RSCM were registered. Relationship between clinical, laboratory and radiologic factors which consist of classic manifestations (cough, productive cough, dyspnea, fever, rales, leucocytosis, infiltrates) and atypical manifestations (decrease of intake and functional status, falls, urinary incontinence) with diagnosis community acquired pneumonia were analyzed. Receiver operating characteristics analysis of C-reactive protein was performed to find its association with diagnosis of pneumonia. Results. Of 158 subject, 106 were confirmed of having pneumonia. Final model of multiple logistics regression analysis revealed three factors: cough (p<0,0001), rales (p=0,02) and infiltrate (p<0,0001) related to diagnosis of pneumonia. All four atypical manifestations were proved unrelated with diagnosis of pneumonia. The area under the ROC curve for c-reactive protein was 0,57 (95% CI 0,47- 0,66). Conclusions. Factors related with diagnosis of community-acquired penumoni in the elderly are cough, rhales and infiltrates. All four atypical manifestations are proven unrelated with diagnosis of pneumonia. C-reactive protein does not predict diagnosis of CAP in the eldery

Karakteristik dan Daya Hasil Aksesi Plasma Nutfah Ubijalar asal Jatim

Identifikasi karakter morfologi dan daya hasil plasma nutfah ubijalar (Ipomoea batatas) dilakukan untuk mendapatkan informasi sumber gen yang berguna pada program pemuliaan untuk merakit varietas unggul baru. Tujuan dari penelitian ini adalah untuk mengetahui karakteristik dan daya hasil aksesi ubijalar yang berasal dari beberapa daerah di Jawa Timur. 31 Aksesi ubijalar koleksi Balitkabi asal Jawa Timur ditanam di IP2TP Jambegede Malang pada Juli-November 2019. Penelitian disusun dalam Rancangan Acak Kelompok (RAK) dengan dua ulangan. Karakter yang diamati adalah: tipe tanaman, bentuk daun, bentuk cuping, jumlah cuping, warna daun muda dan dewasa, pigmentasi batang, warna kulit dan daging umbi, bobot tajuk, jumlah dan bobot umbi per plot, indeks panen, dan hasil umbi. Klon-klon harapan ubijalar menunjukkan karakter morfologi yang cukup beragam. Sebagian besar memiliki tipe tanaman semi kompak, bentuk daun cuping dengan jumlah cuping satu sampai tujuh, warna daun dewasa hijau, warna pucuk hijau dengan ungu melingkari tepi daun, warna umbi bervariasi yaitu: putih, kuning, oranye, dan ungu. Terdapat 13 aksesi yang memiliki potensi hasil &gt;30 t/ha, aksesi MLGI 1574 menunjukkan hasil umbi tertinggi (42,08 t/ha) sedangkan aksesi MLGI 1521 menunjukkan nilai terendah (5,37 t/ha)

Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and the ex‐ tent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (precon‐ ditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experi‐ mentally simulated, under standard laboratory conditions, rewetting of leaves, river‐ bed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative character‐ istics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dis‐ solved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contrib‐ uted most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental vari‐ ables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached sub‐ stances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying event

Simulating rewetting events in intermittent rivers and ephemeral streams: a global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56‐98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached organic matter. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events

Who Eats Whom in a Pool? A Comparative Study of Prey Selectivity by Predatory Aquatic Insects

Predatory aquatic insects are a diverse group comprising top predators in small fishless water bodies. Knowledge of their diet composition is fragmentary, which hinders the understanding of mechanisms maintaining their high local diversity and of their impacts on local food web structure and dynamics. We conducted multiple-choice predation experiments using nine common species of predatory aquatic insects, including adult and larval Coleoptera, adult Heteroptera and larval Odonata, and complemented them with literature survey of similar experiments. All predators in our experiments fed selectively on the seven prey species offered, and vulnerability to predation varied strongly between the prey. The predators most often preferred dipteran larvae; previous studies further reported preferences for cladocerans. Diet overlaps between all predator pairs and predator overlaps between all prey pairs were non-zero. Modularity analysis separated all primarily nectonic predator and prey species from two groups of large and small benthic predators and their prey. These results, together with limited evidence from the literature, suggest a highly interconnected food web with several modules, in which similarly sized predators from the same microhabitat are likely to compete strongly for resources in the field (observed Pianka’s diet overlap indices >0.85). Our experiments further imply that ontogenetic diet shifts are common in predatory aquatic insects, although we observed higher diet overlaps than previously reported. Hence, individuals may or may not shift between food web modules during ontogeny

Sediment respiration pulses in intermittent rivers and ephemeral streams

Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of CO2. We present a global study examining sediments from 200 dry IRES reaches spanning multiple biomes. Results from standardized assays show that mean respiration increased 32–66‐fold upon sediment rewetting. Structural equation modelling indicates that this response was driven by sediment texture and organic matter quantity and quality, which, in turn, were influenced by climate, land use and riparian plant cover. Our estimates suggest that respiration pulses resulting from rewetting of IRES sediments could contribute significantly to annual CO2 emissions from the global stream network, with a single respiration pulse potentially increasing emission by 0.2–0.7%. As the spatial and temporal extent of IRES increases globally, our results highlight the importance of recognizing the influence of wetting‐drying cycles on respiration and CO2 emissions in stream networks