Endangered Shrub Species Research Articles

Temporal variations in root-associated fungal communities of Potaninia mongolica, an endangered relict shrub species in the semi-arid desert of Northwest China.

The semi-arid region of the Western Ordos plateau in Inner Mongolia, China, is home to a critically endangered shrub species, Potaninia mongolica, which originates from ancient Mediterranean regions. Root-associated microbiomes play important roles in plant nutrition, productivity, and resistance to environmental stress particularly in the harsh desert environment; however, the succession of root-associated fungi during the growth stages of P. mongolica is still unclear. This study aimed to examine root-associated fungal communities of this relict plant species across three seasons (spring, summer and autumn) using root sampling and Illumina Miseq sequencing of internal transcribed spacer 2 (ITS 2) region to target fungi. The analysis detected 698 fungal OTUs in association with P. mongolica roots, and the fungal richness increased significantly from spring to summer and autumn. Eurotiales, Hypocreales, Chaetothyriales, Pleosporales, Helotiales, Agaricales and Xylariales were the dominant fungal orders. Fungal community composition was significantly different between the three seasons, and the fungal taxa at various levels showed biased distribution and preferences. Stochastic processes predominantly drove community assembly of fungi in spring while deterministic processes acted more in the later seasons. The findings revealed the temporal dynamics of root-associated fungal communities of P. mongolica, which may enhance our understanding of biodiversity and changes along with seasonal alteration in the desert, and predict the response of fungal community to future global changes.

The complete plastid genome of the endangered shrub Brassaiopsis angustifolia (Araliaceae): Comparative genetic and phylogenetic analysis.

Brassaiopsis angustifolia K.M. Feng belongs to the family Araliaceae, and is an endangered shrub species in southwest China. Despite the importance of this species, the plastid genome has not been sequenced and analyzed. In this study, the complete plastid genome of B. angustifolia was sequenced, analyzed, and compared to the eight species in the Araliaceae family. Our study reveals that the complete plastid genome of B. angustifolia is 156,534 bp long, with an overall GC content of 37.9%. The chloroplast genome (cp) encodes 133 genes, including 88 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. All protein-coding genes consisted of 21,582 codons. Among the nine species of Araliaceae, simple sequence repeats (SSRs) and five large repeat sequences were identified with total numbers ranging from 37 to 46 and 66 to 78, respectively. Five highly divergent regions were successfully identified that could be used as potential genetic markers of Brassaiopsis and Asian Palmate group. Phylogenetic analysis of 47 plastomes, representing 19 genera of Araliaceae and two related families, was performed to reconstruct highly supported relationships for the Araliaceae, which highlight four well-supported clades of the Hydrocotyle group, Greater Raukaua group, Aralia-Panax group, and Asian Palmate group. The genus Brassaiopsis can be divided into four groups using internal transcribed spacer (ITS) data. The results indicate that plastome and ITS data can contribute to investigations of the taxonomy, and phylogeny of B. angustifolia. This study provides a theoretical basis for species identification and future biological research on resources of the genus Brassaiopsis.

Kupeantha yabassi (Coffeeae-Rubiaceae), a new Critically Endangered shrub species of the Ebo Forest area, Littoral Region, Cameroon

SummaryA new species to science of evergreen forest shrub, Kupeantha yabassi M.G.Alvarez & Cheek (Coffeeae - Rubiaceae), is described, illustrated and compared morphologically with the closely similar species K. pentamera. Restricted so far to a single site in evergreen lowland forest near the Ebo Forest, Yabassi, Littoral Region, Cameroon, this species is Critically Endangered using the IUCN 2012 standard due to habitat clearance driven mainly by agriculture, adding to the growing list of threatened species resulting from anthropogenic pressure on Cameroon forests. A revised key to the six species of Kupeantha is presented. Two distinct geographical and ecological species groupings within the genus are identified and discussed. Notes are given on other narrowly endemic and threatened species in the Ebo Forest area, a threatened centre of diversity important for conservation in the Littoral Region.

Growth and physiological acclimation to shade in young plants of Adesmia bijuga Phil., a critically endangered species in central Chile

Adesmia bijuga Phil. is an endemic and endangered shrub species of central Chile. Its potential shade intolerance is one of the leading hypotheses for its vigor loss when the species grows beneath closed canopies. The objective of this study was to assess the growth and physiological acclimation to the shade of young plants of A. bijuga. A nursery experiment was established with three light levels based on the interception of photosynthetic active radiation (PAR) (TRT0: control at full sun; TRT60: 60% shaded; TRT90: 90% shaded), and maintained for 71 days during the summer season. Growth and leaf morpho-physiological responses were evaluated at the beginning, at the middle, and at the end of the experiment. The shading treatment increased plant height (H), live crown percentage (Lcrown), and specific leaf area (SLA) compared to the control treatment at full sun. However, light-saturated photosynthetic rate (Amax), dark respiration rate (Rd), and light compensation point (Γi) were higher in TRT60 than in the other treatments, while no differences were found among treatments for the apparent quantum yield (α). At this stage of plant development, our results suggest high acclimation plasticity of A. bijuga to light levels; however, a semi-shade environment (i.e., TRT60) favored a better performance of the species.

Characterization of the complete chloroplast genome sequence of the endangered species Platycrater arguta (Hydrangeaceae)

Platycrater arguta is a rare and endangered shrub species endemic to East Asia. Here, we report the complete chloroplast (cp) genome structure and its taxonomic position within Hydrangeaceae to promote its conservation and restoration. The complete cp genome of P. arguta was 157,810 bp in length and contained a large single-copy region (LSC) of 86,823 bp and a small single-copy region (SSC) of 18,735 bp, as well as a pair of inverted repeat (IR) regions of 26,126 bp, each. 113 unique genes are predicted in this cp genome, including 79 protein-coding genes, 30 transfer RNA (tRNA) genes and 4 rRNAs. Maximum-likelihood (ML) phylogenetic analysis based on 79 shared cp CDS (coding DNA sequences) of 19 species reveals a close relationship between P. arguta and Schizophragma hydrangeoides.

Site- and species-specific climatic responses of two co-occurring shrubs in the temperate Alxa Desert Plateau, northwest China

In the context of global precipitation anomalies and climate warming, the evolution of fragile desert ecosystems, which account for one-third of the world's land area, will become more complex. Studies of regional climate change and ecosystem response are important components of global climate change research, especially in arid desert regions. Zygophyllum xanthoxylum and Ammopiptanthus mongolicus are two dominant but endangered shrub species in the Alxa Desert in the arid region of central Asia. Using dendrochronological methods, we studied the response of radial growth of those two species to climate factors, and the adaptability of the two shrub populations under a regional warming trend. We found that radial growth of both shrubs was mainly affected by precipitation during the growing season. In additionally, along with the decrease of precipitation and the increase of temperature from east to west of Alxa desert Plateau, the limiting effect of drought during the growing season on radial growth increased. The climate response characteristics and changes between dry and wet periods exhibited spatial and temporal heterogeneity due to micro-level geomorphological factors. Under a regional climate warming trend, individual growth and population development of the two endangered shrubs will be adversely affected. In areas where these species are naturally distributed, populations will gradually become concentrated in micro-geomorphic regions with better soil moisture conditions, such as low-lying areas in the gullies that develop in alluvial fans. This finding has important scientific significance for understanding the development of the region's dominant shrub populations and protection of these and other endangered plants in arid desert areas.

Stanowiska reliktowego gatunku Betula humilis (Betulaceae) w Dolinie Górnego Nurca na Nizinie Północnopodlaskiej

Betula humilis Schrank (shrubby birch) is among the most endangered shrub species in Poland. All localities are in the eastern and northern parts of the country, where the species reaches the western border of its geographical range in Europe. Betula humilis is disappearing in Poland due to wetland melioration and shrub succession. Over 80% of the localities described in Poland have not been confirmed in the last 20 years. Five new localities of B. humilis in the North Podlasie Lowland were recorded from 2008 to 2019 in the Upper Nurzec Valley (Fig. 1): 1–1.5 km south-west of Pawlinowo village (in the ATPOL GC7146 plot) and 1.5–2 km north-west of Żuki village (ATPOL GC7155, GC156 and GC166). The population near Pawlinowo (locality 1) is currently composed of ~80 individuals (101 individuals were noted in 2010) and is one of the largest populations in north-eastern Poland. Betula humilis grows there within patches dominated by Salix rosmarinifolia and megaforbs. The population at locality 5 is composed of 18 individuals. At the remaining localities, only 1–4 individuals were found, scattered along drainage ditches surrounded by hay meadows. At some of these localities the species is threatened with extinction. It is suggested to remove competitive trees and shrubs (mainly Populus tremula, Betula pubescens and Salix cinerea) in order to maintain the local populations.

Post-fire resprout in an endangered and narrow endemic shrub from rupestrian grasslands, Serra do Cipó, southeastern Brazil

Although there is evidence that the vegetation from rupestrian grasslands is resilient to fire, investigations about the effects of increasing frequency of anthropogenic fires in the rare and endemic plants from this ecosystem are still incipient. In this study, we monitored the post-fire resprouting of the endemic and endangered shrub species Coccoloba cereifera Schwacke (Polygonaceae) from rupestrian grasslands, southeastern Brazil. Five months after the fire 100% of the monitored individuals resprouted. However, one year after the fire, the burned plants had the ramet length 24% lower and number of leaves 53.5% smaller in relation to unburned plants. Burned plants showed a much higher relative growth rate in number of leaves and much lower reproductive investment compared to unburned plants. Although the studied species showed a high ability to resprout after fire, the pattern of vegetative growth and reproductive investment showed by the burned plants suggested that the increasing frequency of anthropogenic fires represents a serious threat to C. cereifera.Keywords: Coccoloba cereifera, conservation, Espinhaco Range, plant growth, reproductive phenology.

The Effect of Controlled Burns on Abundance of Woody Species in Appalachian Pine-Oak Forests at Buck Mountain, West Virginia

ABSTRACT: Each year, the US Forest Service uses prescribed fires within the George Washington and Jefferson National Forest (GWJNF). Burns are prescribed in the growing (late April–October) and dormant season (November–mid-April). The goal of the burns is to reinstate the natural fire regime, returning forests to their original species composition. Currently in GWJNF, Appalachian pine-oak forests are experiencing an increase in fire-intolerant species, while Quercus species and Gaylussacia brachycera, an endangered shrub species, are declining. In the summer of 2014, a vegetation survey was conducted on Buck Mountain, West Virginia, to determine if there was a significant difference between dormantand growing-season burns compared to a no-burn control. A total of 60 plots (15 per treatment) was established within a site burned once (in the dormant season), a site burned twice (dormant season burn followed by a growing-season burn), a site burned twice (both dormant season), and a site protected from fire ...

The Formation of the Patterns of Desert Shrub Communities on the Western Ordos Plateau, China: The Roles of Seed Dispersal and Sand Burial

The western Ordos Plateau is a key area of shrub diversity and a National Nature Reserve of endangered shrub species in north-west China. Desert expansion is becoming the most important threat to these endangered species. However, little is known about the effects of sand burial on the dynamics of the shrub community. This study aims to investigate how the shrubs as a community and as different individual shrubs respond to the disturbances caused by the desert expansion. The approach used by this study is to separate the seed-dispersal strategy from the sand-burial forces that are involved in structuring the shrub communities at different disturbance stages. Four communities for different disturbance stages were surveyed by using 50×50 m plots. The individual shrubs were classified into coloniser and successor groups at the seed-dispersal stage and strong and weak sand-burial tolerance groups at the sand-expansion stage. We employed spatial point pattern analysis with null models for each community to examine the seed-dispersal strategy and sand-burial forces affecting community distribution patterns. At the seed-dispersal stage, the interactions between the colonisers and the successors showed significant positive correlation at a scale of 0–1 m and significant negative correlation at a scale of 2 m; significant negative correlations between the groups with strong and weak sand-burial tolerance in the early stage of sand expansion at scales of 3–6 m, and significant positive correlation in the later stage of sand expansion at a scale of 13 m, were found. Seed-dispersal strategy is a reasonable mechanism to explain the shrub community pattern formation in the earlier stages, whereas sand burial is the primary reason for the disappearance of shrubs with weak sand-burial tolerance, this irreversible disturbance causes homogenisation of the community structure and produces aging populations of shrub species. This has an important influence on the succession direction of desert shrub communities.

Isolation and characterization of microsatellite loci for Menziesia goyozanensis, an endangered shrub species endemic to Mt. Goyo in northern Japan

Menziesia goyozanensis, a Japanese kind of fool’s huckleberry, is a shrub species endemic only to Mt. Goyo in northern Japan. This species is listed as ‘critically endangered’ in the Red Data Book of wild plants in Japan, and only a single population has yet been discovered. We isolated and characterized 16 microsatellite loci for this species. The number of alleles ranged from 2 to 25. The range of expected heterozygosities was 0.292–0.917. Five of the 16 microsatellites were not conformed to Hardy–Weinberg equilibrium, probably due to the restricted population size, genetic drifting and the presence of null alleles. These 16 microsatellite loci gave a combined non-exclusion probability of <1.65E–15 in the sampled population. In Menziesia pentandra, which is closely related species to M. goyozanensis, the number of alleles detected and the expected heterozygosities of twelve loci ranged from 3 to 19 and 0.536 to 0.966, respectively. These informative microsatellite markers will be useful in studies of population genetic structure for these species.

Development of microsatellite markers for Euchresta japonica and E. formosana (Leguminosae)

We isolated 13 microsatellite loci from Euchresta japonica, an endangered shrub species that grows in warm-temperate forests in East Asia. Of these 13 loci, only one was codominant and polymorphic with five alleles. Cross-species amplification in a related species, E. formosana, detected nine of these loci, all of which were codominant and polymorphic with 2 to 9 alleles. These markers will facilitate further studies on the genetic characteristics of these two Euchresta species.

Development of microsatellite markers for Stachyurus macrocarpus and Stachyurus macrocarpus var. prunifolius (Stachyuraceae), critically endangered shrub species endemic to the Bonin Islands

Stachyurus macrocarpus and S. macrocarpus var. prunifolius are critically endangered shrub species in the Bonin (Ogasawara) Islands, Japan. These species are extremely rare, and the numbers of individuals in wild populations are 68 in S. macrocarpus and 13 in S. macrocarpus var. prunifolius. For the investigation of genetic diversity, genetic structure and relatedness among remnant individuals of these endangered species, we developed eight microsatellite markers from S. macrocarpus var. prunifolius and characterized these markers for S. macrocarpus var. prunifolius and S. macrocarpus using all naturally occurring individuals of these species. The expected heterozygosities of these markers ranged from 0.14 to 0.67 in S. macrocarpus var. prunifolius, and from 0.02 to 0.84 in S. macrocarpus. The markers described here will be useful for investigating the genetic diversity, genetic structure and relatedness among remnant individuals, and planning the restoration of these critically endangered species.

Survival and growth responses of Myricaria laxiflora seedlings to summer flooding

Myricaria laxiflora, an endangered shrub species distributed along the banks of the Yangtze River in the Three Gorges area, is completely submerged from June to October every year. It is generally assumed that summer flooding has a strong impact on the survival and growth of seedlings. We designed an outdoor randomized block experiment on the responses of seedling survival and growth to different flooding depth and flooding duration treatments during the flood season in the Three Gorges area. Seedling survival rate, aboveground biomass, belowground biomass, total biomass, root depth, length of primary branch and the number of primary and secondary branches were examined. M. laxiflora was found to acclimate to summer flooding by becoming dormant and losing biomass. Seedlings of M. laxiflora ceased growing during the summer flooding season, regardless of the flooding depth and flooding duration they were subjected to. The number of primary and secondary branches, aboveground biomass and total biomass of seedlings was reduced with prolonged flooding. The length of primary branches and aboveground biomass were more sensitive to flooding than other measured parameters and differed significantly between the onset and the end of flooding. In each flooding treatment most seedlings of M. laxiflora survived a flooding period of 2 months and recovered rapidly after the flooding was terminated in September. After 3 months of recovery, aboveground biomass, total biomass and the number of the primary branches increased significantly. Furthermore, seedling survival and growth in the flooding treatments were not significantly different from the controls both during the summer flooding stage and in the recovery stage. All of these results suggest that summer flooding does not affect seedling survival and growth in this species. On the contrary, flooding released seedlings from the stress of drought during summer and facilitated seedling establishment. M. laxiflora appears to cope adaptively with the flooding cycle by going into a state of dormancy during the flood season.