Plant Restoration Research Articles

Cultivation of aromatic plant for nature-based sustainable solutions for the management of degraded/marginal lands: techno-economics and carbon dynamic

The cultivation of aromatic grasses on marginal/degraded land attracts attention due to their remediation potential, low input cost, and economic gain. During the distillation of these aromatic grasses, a huge amount of solid and liquid waste (hydrosol) is generated, which is not only rich in carbon content but also has a good amount of nutrient. This review summarized the potential of aromatic plants for the restoration and vaporization of distilled waste into different value-added products. In this review, estimates of the economic cost and carbon dynamics for cultivation, distillation, and waste valorisation of aromatic grasses were made using available data. Based on the literature, the available degraded land reported for India (38,600 ha) was used for the calculation. The review discussed Scientometrics analysis, the remediation potential of aromatic plants, and various routes of valorization of distilled waste generated to achieve sustainable development goals. Scientometrics analysis demonstrated the studies that include the phytoremediation potential of aromatic grasses in recent years. Among the aromatic grasses, Chrysopogon zizaniodes (L.) Nash., Cymbopogon flexuosus and Cymbopogon martini were majorly used for reclamation purposes for dry land, mine-affected areas, and metal and pesticide-contaminated soils. The estimated profitability of the cultivation and carbon sequestration potential of these grasses in marginal/degraded land could be 22–629 million USD. Our estimations showed that the cost of carbon sequestration by the cultivation of the aromatic plant in degraded land could be 16–45 million USD. The conversion of distilled waste generated into compost, vermicompost, and biochar could sequester about 0.02 X105-335 X105 t of carbon (cost: 0.2–1913 million USD). The use of hydrosol and smoke water released during the process could sequester about 0.014 to 7403 t of carbon ( cost 0.001 to 0.42 million USD). Overall the review demonstrated the sustainability and carbon footprinting of the remediation process by aromatic grasses. The review allowed the exploration of knowledge-based strategies to unlock the potential of aromatic plants for restoration and carbon sequestration, along with the value addition of distilled waste in a sustainable manner. However, more databases are needed to support the information, which includes the productivity and selectivity of individual aromatic plant for different soil and agro-climatic regions.Graphical

Defense mechanisms of alfalfa against cyclic tetramethylene tetranitramine (HMX) stress

Much attention has been paid to the environmental toxicity and ecological risk caused by cyclic tetramethylene tetranitramine (HMX) pollution in military activity sites. In this study, the response mechanism of alfalfa plants to HMX was analyzed from the aspects of the photosynthetic system, micromorphology, antioxidant enzyme system, mineral metabolism, and secondary metabolism, in order to improve the efficiency of plant restoration. Exposure to 5 mg·L−1 HMX resulted in a significant increase in leaf N content and a significant increase and drift of the Fourier transform infrared protein peak area. Transmission electron microscopy images revealed damage to the root system subcellular morphology, but the plant leaves effectively resisted HMX pressure, and the photosynthetic parameters essentially maintained steady-state levels. The root proline content decreased significantly by 23.1–47.2 %, and the root reactive oxygen species content increased significantly by 1.66–1.80 fold. The roots regulate the transport/absorption of many elements that impart stress resistance, and Cu, Mn, and Na uptake is significantly associated with secondary metabolism. The metabolism of roots was upregulated in general by HMX exposure, with the main differences appearing in the content of lipids and lipid-like molecules, further confirming damage to the root biofilm structure. HMX causes an imbalance in the energy supply from oxidative phosphorylation in roots and generates important biomarkers in the form of pyrophosphate and dihydrogen phosphate. Interestingly, HMX had no significant effect on basic metabolic networks (i.e., glycolysis/gluconeogenesis and the tricarboxylic acid cycle), confirming that alfalfa has good stress resistance. Alfalfa plants apparently regulate multiple network systems to resist/overcome HMX toxicity. These findings provide a scientific basis for improving plant stress tolerance and understanding the HMX toxicity mechanism.

Study on Purification Efficiency of Novel Aquatic Plant Combinations and Characteristics of Microbial Community Disturbance in Eutrophic Water Bodies

Aquatic plant restoration is an important technique for the treatment of eutrophic water bodies. There are significant differences in pollutant removal efficiency among different combinations of aquatic plant species in eutrophic water bodies. Therefore, further research on the selection of suitable combinations of aquatic plant species is of great significance for the restoration of eutrophic water bodies. This study investigated the pollutant removal efficiency and bacterial community structure of three novel combinations of aquatic plants, including Lythraceae, Nymphaea, and Myriophyllum (LNM group), Lythraceae, Nymphaea, and Hydrilla verticillata (LNH group), and Lythraceae, Nymphaea, and Vallisneria (LNV group), as well as a control group (CK group). The components of the CK group were only sediment and culture water without any plants. The results show that on one hand, the LNH group had the highest removal rate of COD (90.29%); the LNV group exhibited the highest removal rates for NH4+-N and TN, with removal rates of 61.20% and 82.94%, respectively; and there was no significant difference in the removal rate of TP among the experimental groups, except for the LNH group, which showed higher initial removal efficiency for TP. On the other hand, plant combinations had different impacts on the top 13 dominant microflora at the phylum level. Proteobacteria and Actinobacteria showed the highest removal efficiency for COD in the LNH group, while Verrucomicrobi, Chloroflex, and Acidobacteria showed higher removal efficiency for NH4+-N and TN in the LNV and LNH groups. In summary, the three different combinations of aquatic plants exhibited distinct pollutant removal characteristics, significantly altered the structure of the microbial community, and provided a theoretical basis for their practical application in the restoration of eutrophic water bodies.

NATURAL REGENERATION IN MIXED PLANTING FOR ECOLOGICAL RESTORATION IN THE COASTAL PLAIN OF PARANÁ STATE, BRAZIL

Pastures occupy approximately 20% of the Brazilian territory and a significant part of these areas are degraded and have legal environmental liabilities. Ecological restoration is necessary to remedy this liability. The objective of the present study was to determine the effectiveness of a forest restoration planting in an area previously used as buffalo pasture, through floristic and phytosociological parameters of natural regeneration. The study area was densely populated by invasive exotic grasses (Urochloa spp.) until 2006, when, after eliminating the grasses, six native tree species were planted at 2.5 × 1.6 m spacing. A total of 73 terrestrial plant species were found, the most important being Alchornea glandulosa Poepp. & Endl. - heliophilous, which showed high abundance in all strata. The restoration methodology employed was effective in triggering natural succession in the study area, resulting, after 12 years, in floristic and structural parameters consistent with the initial stage of development of the alluvial Dense Ombrophylous Forest. It is inferred that the well-preserved landscape in the region has been determinant in providing the propagules and dispersers that made the observed species richness possible, while the planting tends to have contributed with the control of grasses and with the recovery of the forest environment, facilitating the arrival and development of these propagules. Evidence of soil degradation by use as pasture was observed, and in former buffalo bathing areas neither restoration planting nor natural regeneration developed.

Significance of nitrogen-fixing actinorhizal symbioses for restoration of depleted, degraded, and contaminated soil.

Atmospheric nitrogen (N2)-fixing legume trees are frequently used for the restoration of depleted, degraded, and contaminated soils. However, biological N2 fixation (BNF) can also be performed by so-called actinorhizal plants. Actinorhizal plants include a high diversity of woody species and therefore can be applied in a broad spectrum of environments. In contrast to N2-fixing legumes, the potential of actinorhizal plants for soil restoration remains largely unexplored. In this Opinion, we propose related basic research requirements for the characterization of environmental stress responses that determine the restoration potential of actinorhizal plants for depleted, degraded, and contaminated soils. We identify advantages and unexplored processes of actinorhizal plants and describe a mainly uncharted avenue of future research for this important group of plant species.

An Analysis of the Growth and Photosynthetic Responses of Potted <italic>Veronica pusanensis</italic> Y.N.Lee according to the Shading Levels

Background and objective: Veronica pusanensis, an endemic species of South Korea belonging to the Plantaginaceae family, is found in Busan, South Korea. Due to its high ornamental value, it is expected to be utilized as a flower crop. However, currently it is an endangered species with its habitats being destroyed and reduced.Methods: Therefore, in this study, we analyzed the growth and photosynthetic responses of potted plants of V. pusanensis under different shading levels to enable mass production. Polyethylene (PE) shading films were selected as the shading material, and shading levels were designed at 0, 35, 45, 60, 75, and 99%, respectively.Results: Results showed that shoot height, shoot width, ground cover, leaf length, leaf width, shoot fresh and dry weight, chlorophyll content (SPAD units), and chlorophyll fluorescence parameters Fv/Fm and PIABS were highest under the 35% shading level. This indicates that it is relatively more desirable to grow V. pusanensis in shade culture compared to under direct sunlight. Meanwhile, root fresh weight and dry weight were highest under the 0% shading level.Conclusion: Therefore, it is recommended to grow V. pusanensis under direct sunlight to significantly increase root biomass when the purpose is to facilitate rootage when transplanting plants for habitat restoration. On the other hand, for the cultivation of V. pusanensis as an ornamental flower crop, it is recommended to grow the plants under the 35% shading level to significantly increase plant sizes and maintain ensure the proper functioning of photosynthetic responses in photosystem II (PSII).

Effects of long-term herbaceous plant restoration on microbial communities and metabolic profiles in coal gangue-contaminated soil

The soil microbial diversity in the gangue accumulation area is severely stressed by a variety of heavy metals, while the influence of long-term recovery of herbaceous plants on the ecological structure of gangue-contaminated soil is to be explored. Therefore, we analysed the differences in physicochemical properties, elemental changes, microbial community structure, metabolites and expression of related pathways in soils in the 10- and 20-year herbaceous remediation areas of coal gangue. Our results showed that phosphatase, soil urease, and sucrase activities of gangue soils significantly increased in the shallow layer after herbaceous remediation. However, in zone T1 (10-year remediation zone), the contents of harmful elements, such as Thorium (Th; 1.08-fold), Arsenic (As; 0.78-fold), lead (Pb; 0.99-fold), and uranium (U; 0.77-fold), increased significantly, whereas the soil microbial abundance and diversity also showed a significant decreasing trend. Conversely, in zone T2 (20-year restoration zone), the soil pH significantly increased by 1.03- to 1.06-fold and soil acidity significantly improved. Moreover, the abundance and diversity of soil microorganisms increased significantly, the expression of carbohydrates in soil was significantly downregulated, and sucrose content was significantly negatively correlated with the abundance of microorganisms, such as Streptomyces. A significant decrease in heavy metals was observed in the soil, such as U (1.01- to 1.09-fold) and Pb (1.13- to 1.25-fold). Additionally, the thiamin synthesis pathway was inhibited in the soil of the T1 zone; the expression level of sulfur (S)-containing histidine derivatives (Ergothioneine) was significantly up-regulated by 0.56-fold in the shallow soil of the T2 zone; and the S content in the soil significantly reduced. Aromatic compounds were significantly up-regulated in the soil after 20 years of herbaceous plant remediation in coal gangue soil, and microorganisms (Sphingomonas) with significant positive correlations with benzene ring-containing metabolites, such as Sulfaphenazole, were identified.

Traditional Ethno-Medicinal Plants Used for Treatment of Diabetes by Bhuyan Tribes in Sundargarh District of Odisha, India-An Ethnobotanical Survey

Diabetes mellitus is the most common disease which has conveyed significant well-being intimidation around the world. The accessible synthetic drugs for the fix of Diabetes mellitus are related to significant expense, different incidental effects and a few constraints. Medicinal plants are the storehouse of the phytochemicals which can be helpful for the therapy of various ailments. Medicinal and aromatic plants are the better option in contrast to compound medications with little or no side effects. Ethnomedicinal studies carried out among the Bhuyan tribal groups in the Sundargarh region, Odisha for the investigation of antidiabetic treatments. The Bhuyan tribal group has a rich knowledge of plants which are used in the treatment of different disease causes. The ethnomedicinal data was gathered from interviews and field studies with nearby healers and townspeople. Restorative plants were gathered and related to help from native healers. These kind medicines have been displayed to have huge mending power, either in their normal state or as the wellspring of new items handled by them. Our study is mainly concentrated on plants used by Bhuyan tribal groups in relation to the cure of diabetes. An extensive field survey of different parts of the district was made with the local tribal villagers and ethnomedicinal or ayurvedic drug practitioner’s perusal of published literature and herbarium specimen of different herbaria of the district was done. A sum of 25 plants having a place with 18 unique families used to treat diabetes utilized by Bhuyans of Sundargarh district has been reported. In this report we have prepared detailed notes on the method of preparation of precise doses, the part/parts of plants used and the method of application of doses with scientific names, vernacular names and family names of collected plants are also given. Further, it emphasizes strongly in this regard the optional and rational uses of traditional and natural indigenous medicine. The results of this study showed that these tribal people still depend on medicinal plants in Sundargarh district forest areas. The study thus underlines the potential of ethnobotanical research and the need for the documentation of traditional ecological knowledge pertaining to medicinal plant utilization for the greater benefit of mankind.

Pharmacological, Phytochemistry and Ethnomedicinal profiles of Osyris quadripartita Salz. Ex Decne.: A Critical Review

Osyris quadripartita Salz. ex Decne. (Santalaceae), prominently known as African sandalwood, is one of the most seasoned and most valuable sources of natural fragrance with immense medicinal and commercial significance. O quadripartita has been grown in Africa and Indian sub- continents from the ancient times and esteemed all over the world for its tonic, and the aromatic oils are used in different products for manufacturing expensive perfumes, rare soaps, quality lotions, and sweet-smelling candles. Leaf stem bark and African shoe heart wood the essential oil derived from African sandalwood has been used in various traditional and tribal systems of medicine, like Ayurveda, Siddha, Folk and Unani medicine, in the treatment and counteraction of a great many sicknesses. It is utilized to treat different illnesses, including helminth contaminations, leishmaniases like infection, irregularities, kidney sickness, scavenge, sterile/perfuming, eye torment, cool, anaphylactic shock, epilepsy, circumcision wounds, toothache, tonsillitis, stomach agony, and pee issues. The flexible restorative and medical services significance of sandalwood is ascribed to its rich essential oil of phytochemicals, especially sesquiterpenes. African sandalwood, recently utilized for its ancestral modern purposes, is presently acquiring consideration for its helpful as well as food and nutraceutical utilizes. An intensive bibliographic examination was done by dissecting overall acknowledged logical data sets such as Google scholar, Publons, Sci-Finder, Pub Med, Scopus, Web of Science, Research Gate, perceived reference books, and UGC Care listed as well as non-listed international journals. Current pharmacological examinations have shown a great many pharmacological activities, going from antimicrobial to anti-cancer. No huge poisonousness has been demonstrated by African sandalwood essential oil and its singular constituents; in any case, further concentrate on compound constituents and their components in showing specific natural exercises is expected to comprehend the full phytochemical profile and the complex pharmacological impacts of this plant. The expanded business abuse of African sandalwood and low efficiency of this huge restorative plant have raised worries over its preservation and efficiency upgrade through current instruments and procedures. The complete survey examines conventional purposes, ancestral purposes, ethnopharmacology, phytochemistry, and biological activities of African sandalwood to unveil its restorative and modern worth and distinguish holes requiring future exploration.

Identification of botanicals using molecular biotechnology.

The available information on the abundance of restorative plants on earth is incomplete, and the data regarding botanicals from various countries differ significantly. The substantial development of the worldwide natural botanical market is attributable to the expanding revenue of global drug companies trading herbal medicines. This essential type of traditional medical care is depended on by approx. 72-80% of individuals. Even though numerous restorative plants are readily used, they have never been subject to the same strict quality guidelines as conventional drugs. Nonetheless, it is vital to have specific organic, phytochemical, and molecular tools and methods for identifying restorative plant species so that traditional and novel plant products can be safely used in modern medicine. Molecular biotechnology approaches provide a reliable and accurate way to identify botanicals and can be used to ensure the safety and efficacy of plant-based products. This review explores various molecular biotechnology approaches and methods for identifying botanicals.

Positive responses of soil nutrients and enzyme activities to AM fungus under interspecific and intraspecific competitions when associated with litter addition

Arbuscular mycorrhizal fungi mediated-litter decomposition is essential for soil carbon and nutrient cycling. Plant competition profoundly influences soil C, nutrients, glomalin-related soil protein, and enzymes. However, it is unclear how a combined AM fungus and litter addition affects soil properties under interspecific and intraspecific competitions. With 170-day-old Broussonetia papyrifera and Carpinus pubescens seedlings, three treatments of intraspecific or interspecific plant competition, AMF Claroideoglomus etunicatum inoculation or not, and leaf litter addition to soil substrate or not were examined to address differences in plant biomass production, soil organic carbon, total nitrogen and total phosphorus, EE-GRSP, DE-GRSP and T-GRSP, and activity of alkaline phosphatase, catalase and urease. The results were as follows: Root, shoot and total biomass increased in B. papyrifera but decreased in C. pubescens under AM mycorrhization in both intraspecific and interspecific competitions. Under mycorrhization, intraspecific, not interspecific, competition increased SOC and ratios of C/N, C/P, DE-GRSP and T-GRSP. Mycorrhization plus litter addition increased SOC, ratios of C/N, C/P and N/P, EE-GRSP, DE-GRSP, T-GRSP, and alkaline phosphatase activity under intraspecific competition, while soil TN, TP, and catalase and urease activities. Soil C, N, P, EE-GRSP or T-GRSP positively associated with catalase, urease or alkaline phosphatase activities. These results showed that alterations in intra- and interspecific competition induced by AM fungus positively respond to soil C, nutrient, GRSP, and enzyme activities, thus plant competition is a key factor in regulating soil properties. Overall, we suggest that interspecific competition enables AMF to increase soil N and P accumulations and related enzyme activities, while intraspecific competition confers more significant benefits than interspecific competition in improving soil C and GRSP accumulations under a combined AMF and litter addition. The findings highlight the importance of plant competition in improving soil function through AM fungus, which is conducive to understand the mechanisms of plant restoration and nutrient cycling in degraded ecosystems.

Editorial: Recent advances in restoration, preservation, and eco-morphophysiology of plants under integrated management approaches and current climate change

EDITORIAL article Front. Ecol. Evol., 14 June 2023Sec. Conservation and Restoration Ecology Volume 11 - 2023 | https://doi.org/10.3389/fevo.2023.1226967

Conservation and Restoration of Mangroves in Response to Invasion of Spartina alterniflora Based on the MaxEnt Model: A Case Study in China

In China, the invasion of Spartina alterniflora is an important driver for the decrease of mangrove area and ecological service functions related to this habitat. In the past few decades, S. alterniflora clearing and mangrove restoration projects have mainly focused on the areas where it is already changed but ignored the potential distribution areas. This study suggested that implementation of mangrove protection prior to the areas with the threat of S. alterniflora invasion could greatly improve protection efficiency and save costs. Thus, using Maximum Entropy Modeling (MaxEnt), we estimated the potential spatial distribution of both mangroves and S. alterniflora in China, considering the current distribution data, topographical, sediments, sea surface temperature and bioclimatic variables. What’s more, we identified and calculated the potential distributed areas in each province. We aimed to explore (i) the key factors determining the distribution of mangrove and Spartina alterniflora along the coastline and (ii) the hotspots of their competitive occurrence, including S. alterniflora invasion areas and mangroves degradation areas, in order to support mangrove conservation. The model showed that the distance to the coastline and the topography play important roles in the distribution of S. alterniflora, while mangroves were more sensitive to the range of the annual sea surface temperature. Our results furthermore confirm that S. alterniflora has a wider potential distribution area (~10,585 km2) than mangroves (~9124 km2) at the coastline of China; and predict the provinces Zhangzhou, Quanzhou, Zhanjiang, Beihai and Wenzhou as hotspots for the competition between mangroves and S. alterniflora. We propose that priority should be given to the protection or restoration of mangrove plants in those areas which are co-suitable for mangroves and S. alterniflora. In these areas, management measures should be conducted that hinder S. alterniflora invasions or clear existing S. alterniflora plants, firstly. This study provides guidance for the management of native species by preventing biological invasion.

Ecological restoration in the age of apocalypse.

Billions of dollars are spent annually on ecological restoration efforts around the world and yet successful attainment of restoration targets still falls short in many regions. Globally, ecosystem restoration is becoming increasingly challenged with changes in climate. Years with extreme climatic events that limit plant establishment, such as severe drought, heatwaves, and floods are projected to increase in frequency. A critical evaluation of current ecological restoration practices and changes to those practices are needed to attain global restoration targets. For plant restoration, many efforts globally focus on planting in a single year following disturbance. The odds of restoration efforts being conducted in a year that is inconducive to plant establishment may be calculated using climatic risk data. We propose a risk-mitigation approach to restoration wherein plantings are conducted across multiple years for projects in a bet-hedging strategy and evaluated through an adaptive management approach.

Changes of nutrients and microbial communities in recovery process of abandoned rare earth tailings

Rare earth element (REE) mining has wrought severe ecosystem destruction, particularly in the loss of carbon (C), nitrogen (N), and phosphorus (P). Furthermore, its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood. In this study, an investigation was conducted to determine C, N, and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5 (1.5-Y), 7 (7-Y), 10 (10-Y), and 14 (14-Y) years and at an unmined site (the control group) in Jiangxi Province, China. Longitudinal tailing delamination at each site was investigated in 0–15 (layer 1) and 15–30 (layer 2) cm tailing layers. During the abandoned duration of REE tailings, C and P in layer 1 continued to recover from 1.62 to 8.51 g kg-1 and from 0.71 to 1.94 g kg-1, respectively; N losses of 0.60 and 0.22 g kg-1 occurred at the 1.5-Y and 10-Y sites, while N in layer 1 slightly increased at the 14-Y site. Mesorhizobium, Methylosinus, Bradyrhizobium, Pseudomonas, and Azospirillum were dominant bacteria at the 14-Y site and in the control. The relative abundances of N-fixing bacteria Mesorhizobium (32.94%), Sinorhizobium (0.24%), Frankia (0.71%), and Burkholderia (2.38%) at the 14-Y site were 1.33–3.97 times those in the control (24.19%, 0.18%, 0.32% and 0.60%, respectively), which was helpful for tailing N recovery. At the 14-Y site, Tylospora (50.24%), Luellia (11.02%), Tomentella (6.94%), and Chaetomium (4.34%) were the dominant fungal genera, while Tylospora (56.93%), Suillus (11.45%), and Penicillium (6.78%) predominated in the control. The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site (0.42%) was 4.2 times that in the control (0.1%), which may lead to the improved tailing P solubility. At the 14-Y site, woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas. This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings, thus providing a novel insight into ecological recovery and restoration after mining.

Environmental Drivers of Gross Primary Production and Evapotranspiration at a Robinia pseudoacacia L. Restoration Plantation

Black locust is the second-most-often planted tree worldwide, particularly for restoration plantations, but drought dieback and growth declines are being reported. Currently, we lack information on these ecosystems’ water and carbon fluxes, in relation to climatic variability. Here, we employed eddy covariance to determine the gross primary production (GPP) and evapotranspiration (ET) of a black locust post-mining restoration plantation in NW Greece over c. 2.5 years. Additionally, we applied Generalized Additive Models (GAMs) to study the effects of key environmental drivers (vapour pressure deficit—VPD, soil water content—SWC, solar radiation—Rg and enhanced vegetation index—EVI) on GPP and ET during summer months. Both diurnally and seasonally, GPP increased with increasing Rg, SWC and EVI, but was saturated after certain thresholds (Rg: 400 W m−2, SWC: 25%, EVI: 0.65). In contrast, GPP declined strongly with increasing VPD. Overall, GPP was maintained at a high level, at the cost of ET, which constantly raised with increasing solar radiation and SWC and was not responsive to enhanced VPD, indicating a non-conservative water use. At present, these black locust plantations exhibit favourable productivity and no drought stress, but increasing VPD in the context of climate change may, ultimately, negatively impact these ecosystems.

Evaluation of the adaptive potential of three non-native multipurpose species for soil rehabilitation

Soil rehabilitation involves restoring their capacity to provide goods and services; however, there is a lack of information regarding the survival and growth responses of individual species to local environmental variations. This study evaluated the adaptation capacity of three non-native multiple-use species in agroforestry design, in a degraded semiarid temperate climate zone located in the Tula watershed in Mexico, assessing their survival, growth of morphological variables, and death risk for use as soil restoration plants. According to the slope of the terrain, the species were planted in an agroforestry arrangement of lines and ridges. Plants were selected according to their multipurpose potential, including their taxonomy, form, function, and use, as well as their soil and climatic conditions. Survival rates for all three species were below acceptable levels (< 49%). Neither Senna multiglandulosa nor Sedum dendroideum adapted well to the soil and climate of the site, since their survival rates were below acceptable (sim 17<49mathrm{%}). Aloe sp. adapted to the edaphoclimatic conditions of the site because its survival rate was excellent (sim 97 ge 90%). Climate conditions during the autumn and winter affected growth rates of Senna multiglandulosa and Sedum dendroideum. Aloe sp. growth rates were only affected by climatic conditions during the winter months. Senna multiglandulosa's final height reduced death risk by 1.50%. Sedum dendroideum's final diameter, initial canopy cover and canopy growth rate reduced the risk of death by 55.1, 5.1 and 30.7%, respectively. The height growth rate of aloe and initial canopy cover reduced the risk of death by 93.9 and 2.4%, respectively. Plant species evaluated showed varying levels of adaptation. Aloe sp. was the species that adapted best to the site's soil and climate.

Genetic assessment of the value of restoration planting within an endangered eucalypt woodland

Assessment of woodland restoration often focusses on stand demographics, but genetic factors likely influence long-term stand viability. We examined the genetic composition of Yellow Box (Eucalyptus melliodora) trees in endangered Box-Gum Grassy Woodland in SE Australia, some 30 years after planting with seeds of reportedly local provenance. Using DArT sequencing for 1406 SNPs, we compared genetic diversity and population structure of planted E. melliodora trees with remnant bushland trees, paddock trees and natural recruits. Genetic patterns imply that natural stands and paddock trees had historically high gene flow (among group pairwise FST = 0.04–0.10). Genetic diversity was highest among relictual paddock trees (He = 0.17), while diversity of revegetated trees was identical to natural bushland trees (He = 0.14). Bayesian clustering placed the revegetated trees into six genetic groups with four corresponding to genotypes from paddock trees, indicating that revegetated stands are mainly of genetically diverse, local provenance. Natural recruits were largely derived from paddock trees with some contribution from planted trees. A few trees have likely hybridised with other local eucalypt species which are unlikely to compromise stand integrity. We show that paddock trees have high genetic diversity and capture historic genetic variety and provide important foci for natural recruitment of genetically diverse and outcrossed seedlings.

Potential to Improve Wyoming Big Sagebrush Establishment with a Root-Enhancement Seed Technology

Restoration of the foundational species, big sagebrush (Artemisia tridentata Nutt.), of the sagebrush steppe biome has not kept pace with the loss of habitat, demanding new tools to improve its restoration. Seed enhancement technology (SET) is one approach that is increasingly being tested in native plant restoration as a means to overcome establishment barriers. Like many semiarid shrubs, sagebrush faces establishment barriers from inadequate moisture, competition from faster-growing grasses, and limited available nutrients. We performed a series of laboratory trials testing whether nutrient amendments could be applied to sagebrush seed using a SET to increase root length and biomass, thereby potentially increasing seedling survival. We initially tested 11 amendments applied directly to bare seeds; of these, a high-phosphorus fertilizer resulted in a 2.7x increase in root biomass and 71-mm increase in root length over the control. We then tested incorporating this fertilizer at multiple concentrations into a pellet SET and a ground dust. Although the fertilizer, particularly at higher concentrations, conferred some enhancement to seedling biomass, the pellet treatments had substantially lower emergence and survival than bare seed and dust treatments. These results indicate the potential for a “root-enhancement” SET to benefit sagebrush and other species like it; they also illustrate some of the challenges of SET development for native species. Sagebrush has small seeds that typically need light to germinate. Further work is needed to develop an appropriate technology that does not negatively impact emergence but still provides enough nutrients for enhanced root growth. Field testing is also needed to determine if increases in root growth translate into greater survival. Given the low success rate of sagebrush seeding in restoration projects, however, we suggest that it is worth considering root-enhancement SET alongside other efforts to improve sagebrush establishment success.

Towards recovery of an endangered Pacific island endemic: Experimental evidence for shortening juvenility of Serianthes plants using a shade and trellis system to generate vigorous growth and precocious flowering

Background and Research Aims Conservationists aiming to establish seed orchards or restoration plantings benefit from methods that reduce tree juvenility. Previous studies suggest that seedling and sapling mortality is the major limitation to natural population recovery of the critically endangered Serianthes nelsonii. To enable effective restoration actions new methods are required to reduce sapling mortality. Methods Ex situ experiments were used to determine if trellised, shaded growth conditions would reduce juvenility of Serianthes saplings. Serianthes kanehirae was used as a surrogate for S. nelsonii. Stem growth was trained horizontally to a wire trellis in shaded tunnels of differing lengths (0, 3, 6, 9 or 12 m). Time to reach the end of each tunnel, and subsequent vertical stem growth in full sun were recorded until flower production commenced. Results The shortest S. kanehirae juvenile phase occurred under 12 m tunnels, with first flower production within a year (351 ± 10 days, mean ± SE). The juvenile phase increased in duration as tunnel length shortened. The control plants did not produce flowers during the study. Conclusion Horizontal trellised support of shaded stems was effective in reducing juvenile phase duration of Serianthes saplings. Implications for Conservation Serianthes seed orchards may use shaded trellises to produce seeds on young plants to rapidly boost species recovery efforts. The production of seeds in managed conservation gardens may improve recovery efforts by reducing the need to remove seeds from in situ communities. Therefore, this simple protocol may prove beneficial for both in situ and ex situ conservation of all federally listed woody plant species in the region.