The emergent past: past natural and human disturbances of trees can reduce their present resistance to drought stress

Forest tree growth is primarily explained, modelled, and predicted depending on current age or size, environmental conditions, and competitive status in the stand. The accumulated size is commonly used as a proxy for a tree's past development. However, recent studies suggest that antecedent conditions may impact present growth by epigenetic, transcriptional, proteomic, or metabolic changes alongside physiological and structural properties. Here, I analysed the ecological memory effect embedded in the xylem as a tree-ring structure. I used 35 mature Norway spruces (Picea abies (L.) H. Karst.) and 36 European beeches (Fagus sylvatica L.) of the Kranzberg Forest water retention experiment KROOF in South Germany to scrutinise how their past development determines the growth of control plots and plots with 5-year water retention. I hypothesised that the current size and growing conditions determine tree growth and drought stress resistance. Metrics quantifying the trees’ recent and past growth, and correlation and linear mixed models with random effects revealed the following ecological memory effects. (1) For both species, the progressive growth course, low inter-annual growth variation in the long term, and low growth deflections in the recent past increased the growth resistance to drought. (2) The correlation between the past growth metrics and current stress reactions revealed that legacy effects could reach back 5–30 years; I found short- and long-term ecological memory. (3) Parameters of model prediction of the basic model with only size as a predictor of tree growth could be improved. The results suggest differences in the internal stem structure and ring pattern cause-specific differences in the trees' functioning and growth. I conclude that a long-term progressive increase and low variation in ring width may improve water conduction and reduce embolism in both species. Annual growth variation and low growth events in the recent past may have primed the morphology and allocation of the Norway spruce to better resist drought. The strong reduction in current growth, drought resistance by irregular growth, and past growth disturbances reveal a memory effect embedded in the tree ring pattern, suggesting further exploration and consideration in tree monitoring, growth modelling, and silvicultural prescriptions.

Growth variation and proline accumulation of Echinacea purpurea cultivated to CaCl2 salinity

Purple coneflower (Echinacea purpurea (L.) Moench) is classified as medicinal plant comes from North America and not much developed in Indonesia. E. purpurea can be developed by utilizing suboptimal land such as saline land. This study aims to determine the effect of CaCl2 concentration on growth and proline accumulation of three accessions E. purpurea. This study used a Completely Randomized Design (CRD) with 2 factors and five replications. The first factor is three accessions E. purpurea (accession 1; 2; and 3). The two factor is four concentrations CaCl2 (0; 2500; 5000; and 10000 ppm). The observations are plant height, number of leaves, number of branches and proline accumulation. Data were analyzed using SPSS to test difference. The results showed that highest concentration of CaCl2 can inhibit growth and increase proline accumulation. The highest proline accumulation in accession 2 was 22.8002 µmol g−1, accession 2 as an indicator of accession tolerant to salinity.

Temperature-Driven Growth Variation in a Deep-Sea Fish: The Case of Pagellus bogaraveo (Brünnich, 1768) in the Azores Archipelago

The deep ocean ecosystem hosts high biodiversity and plays a critical role for humans through the ecosystem services it provides, such as fisheries and climate regulation. However, high longevity, late reproduction, and low fecundity of many organisms living in the deep ocean make them particularly vulnerable to fishing and climate change. A better understanding of how exploitation and changing environmental conditions affect life-history parameters (e.g., growth) of commercially important fish species is crucial for their long-term sustainable management. To this end, we used otolith increment widths and a mixed-effects modeling approach to develop a 42-year growth chronology (1975–2016) of the commercially important deep-sea fish species blackspot seabream (Pagellus bogaraveo) among the three island groups of the Azores archipelago (Northeast Atlantic). Growth was related to intrinsic (age and age-at-capture) and extrinsic factors (capture location, temperature-at-depth, North Atlantic Oscillation (NAO), Eastern Atlantic Pattern (EAP), and proxy for exploitation (landings)). Over the four decades analyzed, annual growth patterns varied among the three island groups. Overall, temperature-at-depth was the best predictor of growth, with warmer water associated with slower growth, likely reflecting physiological conditions and food availability. Average population growth response to temperature was separated into among-individual variation and within-individual variation. The significant among-individual growth response to temperature was likely related to different individual-specific past experiences. Our results suggested that rising ocean temperature may have important repercussions on growth, and consequently on blackspot seabream fishery production. Identifying drivers of blackspot seabream growth variation can improve our understanding of past and present condition of the populations toward the sustainable management of the fishery.

EVALUASI PERTUMBUHAN TANAMAN UJI KETURUNAN MERANTI MERAH (Shorea leprosula) UMUR 12 TAHUN DI AREAL IUPHHK-HA PT. ERNA DJULIAWATI KALIMANTAN TENGAH

Red meranti (Shorea leprosula) is one of the superior plants in the application of intensive silviculture (SILIN). As a superior plant, PT. Erna Djuliawati has conducted a progeny test for S. leprosula in the IUPHHK-HA area in Central Kalimantan. The aim of this research was to determine the superior seedlot and genetic growth variation of the S. leprosula in the progeny test plot. The object studied was the 30 seedlots of S. leprosula plants in progeny test plot consists divided into 8 blocks, where each seedlot was 4 plants. The data collected consisted of diameter (cm), tree height (m) and percentage of tree life. The results showed that in the progeny test trial plot there were 5 seedlots with superior growth. The results of the analysis of variance on diameter, height and percentage showed a significant difference between the tested seedlots to the properties measured. High heritability values followed by wide genetic diversity indicate that the appearance of these characters is more determined by genetic factors. The value of moderate diameter genetic progress (8.6%) indicates that the diameter character is supported by genetic factors, so that it can facilitate the progress of selection.Keywords : Progeny test, Shorea leprosula, superior dan genetic variation. AbstrakMeranti merah (Shorea leprosula) merupakan salah satu jenis tanaman unggulan dalam penerapan Silvikultur Intensif (SILIN). Sebagai tanaman unggulan, PT. Erna Djuliawati telah melakukan uji keturuan S. leprosula dalam areal IUPHHK-HA di Kalimantan Tengah. Tujuan penelitian ingin menentukan seedlot yang unggul dan variasi pertumbuhan genetik tanaman uji keturunan S. leprosula dalam plot uji keturunan. Objek yang diteliti adalah tanaman meranti merah dalam plot uji keturunan sebanyak 30 seedlot yang terbagi dalam 8 blok, dimana setiap seedlot sebanyak 4 tanaman. Data yang dikumpulkan terdiri dari diameter (cm), tinggi pohon (m) dan pesentase hidup pohon. Hasil penelitian menunjukkan bahwa dalam plot uji coba keturunan terdapat 5 seedlot yang unggul pertumbuhannya. Hasil analisis keragaman (varians) terhadap diameter, tinggi dan persentase menunjukkan adanya perbedaan yang nyata di antara seedlot yang diuji terhadap sifat yang diukur. Nilai heritabilitas yang tinggi diikuti dengan keragaman genetik yang luas menunjukkan penampilan karakter tersebut lebih ditentukan oleh faktor genetik. Nilai kemajuan genetik diameter sedang (8,6 %) mengindikasikan karakter diameter tersebut didukung oleh faktor genetik, sehingga dapat memfasilitasi kemajuan seleksi.Kata kunci : Uji Keturunan, S. leprosula, unggul, dan variasi genetik.

Effect of Nutrients on Biomass Production of Helminthosporium Tetramera A Leaf Spot Pathogen of Sugarcane (Saccharum Officinarum)

: Helminthosporium tetramera was a pathogen of Saccharum Officinarum, was isolated from diseased Saccharum Officinarum, leaves from Nashik district and used for the present study. Pathogen was grown on the Czapek-Dox liquid medium substituting or adding different carbon, nitrogen to study biomass production. The growth as dry mycelial biomass was observed on the 8th day of incubation period. A grate extent of growth variation was observed on different carbon, nitrogen. Among the carbon source, fructose shows maximum biomass while glucose with minimum biomass. From nitrogen source cobalt nitrate and barium nitrate shows maximum and control condition with minimum biomass was recorded.

Prey Abundance Regulating the Response of an Important Marine Eel Species Conger Myriaster Growth to Water Temperature

Whitespotted conger (Conger myriaster) is a commercially important species in East Asia but the fisheries stock has drastically declined in recent years. Environmental changes are assumed to have profound impacts on the growth pattern of this species, yet the mechanisms that regulate growth remain poorly understood. Here we used otolith measurements to establish growth chronologies of 9-year period (2010–2018) for whitespotted conger in the Yellow Sea and evaluated the effects of environmental variables on the growth pattern. Linear mixed-effects models were used to explain growth variation with abiotic and biotic environmental variables, including seasonal water temperature, prey availability, and population density, and to assess age-dependent responses in growth and the interactions between abiotic and biotic factors. The results indicated that the growth of whitespotted conger positively correlated with spring sea bottom temperature (March-May) and prey per capita, and the influence of prey availability became larger with increasing ages. The model detected significant negative interactions between sea temperature and prey availability, indicating a higher degree of temperature-dependent growth when prey availability was low. Our findings imply that the growth of whitespotted conger is less likely to be influenced by food availability when the spring water temperature is high in the Yellow Sea, and a combination of cold spring and low food availability may result in substantial constrained growth. This study provided the first evidence for the joint effects of abiotic and biotic factors on the growth variation of whitespotted conger, and the information may contribute to sustainable management policies.

Wintertime growth in Atlantic salmon under changing climate: the importance of ice cover for individual growth dynamics

Understanding the dynamic nature of individual growth in stream-dwelling salmonids may help forecast consequences of climate change on northern fish populations. Here, we performed an experimental capture-mark-recapture study in Atlantic salmon to quantify factors influencing wintertime growth variation among juveniles under different scenarios for ice cover reduction. We applied multiple imputation to simulate missing size observations for unrecaptured fish, and to account for individual-level variation in growth rates. The salmon parr exhibited substantial body length shrinkage in early winter, suppressed growth through mid-winter, and increasing growth rates in late winter and particularly in spring. Unexpectedly, the presence of ice cover had no direct effects on wintertime growth. Instead, our results implied increasing energetic costs with reducing ice cover: individuals exposed to absent or shortened ice-covered period gained mass at a lowered rate in spring whereas the present, long ice-covered period was followed by rapid growth. This study emphasizes natural resilience of Atlantic salmon to wintertime environmental variation which may help the species to cope with the reductions in ice cover duration due to climate change.