Prediction of soil seed bank of piedmont and alluvial environments of Dera Ghazi Khan, Punjab, Pakistan

The current focus is on the overall pattern of seed storage present in the fragments of the soil of piedmont and alluvial landscapes of the environment. The present study predicted the seed banks of both soils of alluvial and piedmont zones in different ecological conditions and evaluate the potential of seeds in the restoration of both environments. The composition of the seed bank of soil is mainly affected by the alluvial environment and the structure of cleared area shows that more species of germinating annual grasses and growable seeds with the higher total number. Extant vegetation structures have an important role in the diversity of soil seed reservoirs, whose composition corresponded with the openness of the site. When in situ soil seed bank is recruited, it helps to restore only some components of the plant community in an alluvial environment. In our current research, it was confirmed that seed richness was higher in number at lower elevation (alluvial) than that at high elevation (piedmont). Seed richness showed a significant negative correlation with anions, cations, while significantly positive with altitude that suggests the richness pattern of the overall seed bank of the area is influenced by various environmental factors.

Rainfall amount determines annual herb controls over soil seed bank and its similarity with vegetation in the Tengger Desert

Background Soil seed banks may offer great potential for maintaining and restoring desert ecosystems that have been degraded by climate change and anthropogenic disturbance. However, few studies have explored the year-to-year dynamics in the species composition (richness and abundance) of these desert soil seed banks. Thus, we conducted a 4-year study to assess the effects of environmental factors (meteorology and microtopography) and aboveground vegetation on the soil seed bank of the Tengger Desert, China. Results We found the seed bank was dominated by annual herb species both in species richness and abundance. More rainfall in the growing season increased the number of seeds in the soil seed bank, and quadrat micro-elevation had a negative effect on soil seed bank size. The species composition in the seed bank had significantly larger between-year similarity than that in the aboveground vegetation due to the dominance of annual herb species. For different life forms, the species composition of annual herbs showed distinctly larger temporal similarity between the aboveground vegetation and the seed bank compared with perennial herbs and shrubs. Conclusions Our findings highlight that the combined effects of environmental factors and plant life forms determine the species composition (especially the abundance) of soil seed banks in deserts. However, if degraded desert ecosystems are left to regenerate naturally, the lack of shrub and perennial herb seeds could crucially limit their restoration. Human intervention and management may have to be applied to enhance the seed abundance of perennial lifeforms in degraded deserts.

Ecological restoration through natural regeneration in Chunati Wildlife Sanctuary – a protected area of South-East Bangladesh

PurposeIn this paper, the authors show that ecological restoration potential through natural regeneration of degraded tropical rainforest is possible. This is significant because at present most of the tropical forest of the world, including of Bangladesh, are degraded.Design/methodology/approachRegeneration status of Chunati Wildlife Sanctuary (CWS) was assessed through stratified random sampling method using sample plots of 5 × 5 m in size covering 269 sample plots.FindingsA total of 3,256 regenerating seedlings/saplings of 105 species belonging to 35 families were recorded from CWS. From regenerating tree species, maximum (37.83) family importance value (FIV) index was found for Euphorbiaceae followed by Myrtaceae (18.03). Maximum importance value index (IVI) was found for Aporosa wallichii (21.62) followed by Grewia nervosa (16.41). Distribution of seedlings into different height classes of regenerating tree species was also calculated.Practical implicationsForest scientists are working to find out the best nature-based solution for ecological restoration of tropical rainforests to attain climate resilient ecosystem in a sustainable way. Tropical rain forest has huge plant diversity, and we find that ecological restoration is possible through natural regeneration from its rich soil seed bank. Natural regeneration is the best nature-based solution for sustainable management of the forest.Social implicationsThe authors believe that the findings presented in our paper will appeal to the forest and environmental scientists. The findings will allow readers to understand degraded tropical hill forest ecosystem and its management strategy.Originality/value The authors believe that this manuscript will give a clear picture about degraded tropical hill forest ecosystem and its genetic composition, diversity and soil seed bank status to apply appropriate management strategy.

Efficiency of Methodologies Used in the Evaluation of the Weed Seed Bank under Mediterranean Conditions

The objective of this study was to compare the efficiency of two methodologies, seed germination (SG) and seed physical extraction SPE), to assess the weed community from two locations with different soil and climatic conditions: M, with dry and low soil fertility, and S with high soil humidity and fertility. Over three years of study, the analysis of both methodologies confirmed differences in seed bank composition. In M, fewer seeds were recorded by SG than SPE (13.5% and 86.5% respectively), while in S, the difference between percentages was less (31.58% by SG and 68.41% by SPE). Our findings confirmed that Portulaca oleracea L., Amaranthus blitoides S. Watson and Chenopodium album L. were abundantly found in M. Anacyclus clavatus (Def.) Res. seeds were also found, mainly detected by SG. In S, Stellaria media (L.) Vill. was widely found. All species found in S were similarly detected by SG and SPE. The results confirmed that climatic and soil conditions influenced the efficiency of the methodology used to assess the seed bank. M conditions led to an increased seed reservoir, and both methodologies were necessary to obtain the seed bank composition. In S conditions, the seed bank was continuously renewed, and either one of methodologies defined the seed bank composition equally well.

Environmental Factors Driving Seed Hydration Status of Soil Seed Banks and the Implications for Post-fire Recruitment

Changes in fire regimes due to climate change and fire management practices are affecting the timing, length, and distribution of vegetation fires throughout the year. Plant species responses and tolerances to fire differ from season to season and are influenced by species-specific phenological processes. The ability of seeds to tolerate extreme temperatures associated with fire is one of these processes, with survival linked to seed moisture content at the time of exposure. As fire is more often occurring outside historic dry fire seasons, the probability of fire occurring when seeds are hydrated may also be increasing. In this study, we set out to understand the seasonal dynamics of seed hydration for seeds of Banksia woodland species, and how certain seed traits interact with environmental conditions to influence survival of high temperatures associated with fire. We measured the moisture content of seeds buried to 2 cm in the soil seed bank for four common native species and one invasive species on a weekly basis throughout 2017, along with soil moisture content and environmental correlates. We determined water sorption isotherms at 20°C for seeds of each species and used these functions to model weekly variation in seed water activity and predict when seeds are most sensitive to soil heating. Using Generalised additive models (GAMs), we were able to describe approximately 67% of the weekly variance in seed water activity and explored differences in seed hydration dynamics between species. Seed water activity was sufficiently high (i.e., ≥ 0.85 aw) so as to have created an increased risk of mortality if a fire had occurred during an almost continuous period between May and November in the study period (i.e., 2017). There were brief windows when seeds may have been in a dry state during early winter and late spring, and also when they may have been in a wet state during summer and late autumn. These data, and the associated analyses, provide an opportunity to develop approaches to minimize seed mortality during fire and maximize the seed bank response.

Indigenous Seeds, Seed Selection and Seed Bank for Sustainable Agriculture

Indigenous seeds are grown by the farmers over the years with a strong influence from local natural factors. Such seeds have a higher level of intrapopulation variations and the capacity of buffering the adverse factors. Understanding indigenous seeds along with their diversity are useful to diversify their uses, to assess conservation status, to know the factors making farming areas red zone, and to improve their performance. Selection is the simplest and most common method for the improvement of crop varieties. The variation must be created and maintained to impose selection. Different types of selection can be considered depending on the mode of reproduction of crops. Response to selection and correlated response are estimated to make the selection process more effective. Many different selection approaches can target either developing monomorphic or polymorphic varieties. There are five selection units and can be applied in five crop stages. Farmers’ criteria need to be considered during selection process. Based on the genotypic classes, there are three types of selection namely stabilizing selection, directional selection, and disruptive selection. The most simple and common selection methods are pure lines, mass selection, and class-bulking selection. Orthodox seeds in short, medium, and long-term storage facilities are conserved as a seed bank. Major types are household seed banks, community seed banks, national seeds, natural seed banks, and global seed banks. A seed bank is for assuring the availability of crop diversity for research, study, and production. The common works in seed banks are diversity collection, regeneration, characterization, multiplication, and distribution along with online database management.

Statistical inference for seed mortality and germination with seed bank experiments

Plant population ecologists regularly study soil seed banks with seed bag burial and seed addition experiments. These experiments contribute crucial data to demographic models, but we lack standard methods to analyze them. Here, we propose statistical models to estimate seed mortality and germination with observations from these experiments. We develop these models following principles of event history analysis, and analyze their identifiability and statistical properties by algebraic methods and simulation. We demonstrate that seed bag burial, but not seed addition experiments, can be used to make inferences about age-dependent mortality and germination. When mortality and germination do not change with seed age, both experiments produce unbiased estimates but seed bag burial experiments are more precise. However, seed mortality and germination estimates may be inaccurate when the statistical model that is fit makes incorrect assumptions about the age-dependence of mortality and germination. The statistical models and simulations that we present can be adopted and modified by plant population ecologists to strengthen inferences about seed mortality and germination in the soil seed bank.