Species Composition Of Understory Vegetation Research Articles

Understory diversity and composition after planting of teak and mahogany in Yogyakarta, Indonesia

ABSTRACT Forest rehabilitation is when a desired tree species is planted in degraded forests or lands. Rehabilitation by planting a single tree species is a common way to restore exploited forests to maintain ecological processes. We compared woody and herbaceous understory vegetation between forests rehabilitated by mahogany (N = 12) or teak (N = 12) planted from 1941 until 2003 in Yogyakarta, Indonesia. Understory vegetation of these areas was compared with that of three native forests. Species richness, species diversity, density of plants and proportion of native plants did not differ between the rehabilitated areas and the native forest. Recently rehabilitated areas were different from the native forests while 41–74 yr after rehabilitation, characteristics of understory vegetation approached those of native forest. We described species composition using ordination, and found it to differ between areas rehabilitated with teak and with mahogany and, particularly, between the rehabilitated areas and the native forests. Time since rehabilitation and tree species planted were important for the species composition of understory vegetation. We conclude that the selection of species for rehabilitation and letting rehabilitated areas mature are important for understory development and species diversity.

Seasonal Dynamics of Floodplain Forest Understory–Impacts of Degradation, Light Availability and Temperature on Biomass and Species Composition

Forest understory significantly contributes to matter cycling in ecosystems, but little is known about its carbon pool. This is especially poorly understood in floodplain forests, one of the most threatened ecosystems worldwide. We studied seasonal dynamics of biomass and species composition of understory vegetation in degraded and non-degraded floodplain forests, to improve our understanding of carbon pools in forest ecosystems. We hypothesized that degraded and non-degraded floodplain forests will differ in patterns of seasonal variability of biomass and species composition. The study was conducted in Poznań (W Poland) in two study plots (each with 10 samples) across 22 dates (March–November 2016). In each date, we collected understory aboveground biomass. We evaluated impact of light availability and soil temperature on biomass and species composition. Our study revealed high dynamics of biomass production. We found maximum biomass crop of understory in degraded floodplain forest on 24 April (930.12 ± 48.70 kg ha−1), whereas in non-degraded floodplain forest the maximum occurred on 30 May (768.99 ± 40.65 kg ha−1). At the beginning of the growing season, understory biomass was dominated by spring ephemerals and later these species were replaced by others present for the whole season. Additionally, we confirmed the positive impacts of light availability and temperature on understory primary production. The pattern revealed drove species composition shifts and low differences in biomass crop between consecutive dates. Patterns of understory biomass dynamics differed between degraded and non-degraded plots. Despite study limitations, we provided rare data about understory biomass dynamics of floodplain forests, increasing knowledge about carbon accumulation and cycling in floodplain forests, and contributing to global carbon assessments.

Low impact of disturbance on ecological success of invasive tree and shrub species in temperate forests

Disturbance is claimed to be one of the most important triggers of biological invasions. There is a lack of data about disturbance impacts on the youngest life stage of invasive trees and shrubs. Thus, we aimed to assess the role of disturbances in shaping responses of natural regeneration of three model invasive species—Prunus serotina Ehrh., Quercus rubra L., and Robinia pseudoacacia L.—to disturbances in forest plant communities. Our study was conducted over 3 years on 372 study plots (100 m2), across nine types of temperate forests in Wielkopolski National Park (Poland). Disturbance was assessed using ecological indicator values for disturbance severity and frequency. Our study revealed the high importance of disturbance on species composition of understory vegetation. We also found relationships between ecological success (density and biomass of natural regeneration) of invaders and disturbance indices. These models were statistically significant but their effect sizes were low. Due to the low effect sizes, we can state only limited conclusions about impact of disturbance on ecological success of invasive species natural regeneration. The results suggest that for seedlings (up to 50 cm height—threshold between understory and shrub layer) disturbance, a leading factor in biological invasions of numerous taxa, has a small role in this case. Thus, we may assume that their ecological success is connected with stochastic processes in populations of the invader’s seedlings, rather than with stochastic release from competition caused by disturbances.

Tree species determine soil seed bank composition and its similarity with understory vegetation in a semi-arid African savanna

IntroductionThe presence of larger trees in semi-arid African savannas creates sub-habitats, which influences on herbaceous plant communities grown under their canopies differently from opened areas. Knowledge of seed banks accumulated in the soils over time beneath larger trees could facilitate the recovery of plant communities that might disappear due to sustained heavy grazing, prolonged fire, or other anthropogenic factors in semi-arid African savannas. However, the impact of larger trees on soil seed bank composition and its similarity with plant communities grown under their canopies are less understood in semi-arid African savannas. Therefore, we studied the effect of leguminous and non-leguminous tree species and their canopies on soil seed bank (SSB) composition and its similarity with understory vegetation (USV) in a semi-arid savanna of Ethiopia.MethodsWe selected 20 matured trees from 3 dominant tree species, representing one leguminous (Acacia robusta Burch) and 2 non-leguminous tree species (Ziziphus spina-Christi and Balanites aegyptiaca (L.) Del), found in isolation, a total of 60 trees for this study. Under each selected individual tree, the species composition of USV were recorded using 1-m2 quadrat in four directions (north, south, east, and west) under the inside and outside tree canopies during the flowering stage. Similarly, soil samples in a 1-m2 quadrat were also collected under the inside tree canopies and their corresponding outside canopies, in each individual tree, for the determination of SSB composition, using a seed emergence method. Then, the soil was thoroughly mixed after removal of all roots and plant fragments, and spread over sand in plastic pots to a depth of 20 mm. The pots were placed at random in a glasshouse, examined every 3 days, for the first 2 months, and thereafter weekly for 6 months. A total of 960 soil samples were used for the determination of SSB composition during this study.ResultsA total of 64 species were emerged from the SSB samples, of which 27 were grasses (19 annual and 8 perennial grasses), 35 annual forbs and 2 woody species. Acacia robusta had a higher seedling density in the SSB compared to other tree species, whereas Z. spina-Christi had higher species diversity in the SSB than other tree species. Moreover, seedling density and species diversity were higher under the inside canopies than outside tree canopies. The mean similarity in species composition between the SSB and USV was low. However, it was higher under the leguminous trees than non-leguminous trees, and under the inside tree canopies than outside canopies.ConclusionsWe found that mature tree species maintained a higher SSB species diversity and abundance under their canopies than the surrounding opened areas. Therefore, conservation of mature dominant tree species is of paramount importance for ecological stability and possible restoration of degraded semi-arid savannas under the changing climate and global warming.

Ground-dwelling spider diversity in rare European oak and yew woodlands and the impact of grazing

In Ireland only 2 % of the total land area is native woodland, which tends to be small and fragmented. Killarney National Park in south-west Ireland contains the most extensive semi-natural woodland in the country, and includes oak (Quercus petraea) and yew (Taxus baccata) woodlands which are internationally protected. Here, over-grazing by large populations of red deer (Cervus elaphus) and Asian sika deer (Cervus nippon) have lead to changes in overstory and understory vegetation species composition and structure. This study presents the first description of ground-dwelling spider fauna in the rare woodlands of Killarney National Park and asked (1) do these rare woodlands support rare or specialist species, (2) does deer grazing have an effect on spider abundance, richness and species composition in the park, (3) what management recommendations can be made for deer in the park? Active ground-dwelling spiders were sampled in the oak and yew woodlands of the park by pitfall trapping within deer-proof exclosures and adjacent grazed controls. Four spider species classified as vulnerable were collected from these woodlands: Agyneta subtilis occurred in the oak and yew woodlands but Saaristoa firma, Tapinocyba insecta and Walckenaeria dysderoides were collected only in the oak woodland. Killarney National Park may be important for five species, not typically found in plantation forests, which rely on nationally scarce habitats. Deer grazing was linked with decreased ground-dwelling spider abundance and species richness in the oak woodland by reducing structural diversity of the habitat. Fewer effects of grazing were detected in the yew woodland, possibly due to increased culling in the area. Results provide evidence that controlling deer grazing is important for woodland biodiversity in Killarney National Park. Incorporating deer into woodland management in the park is recommended to maintain low grazing levels which will prevent woodland closure and maintain ground vegetation diversity.

The Role of the Seed Bank in Recovery of Understory Species in an Eastern Oregon Ponderosa Pine Forest

Abstract Restoration treatments in ponderosa pine forests may not promote understory recovery where residual understory plant abundance or propagule availability is insufficient for natural re-establishment. The value of the seed bank for understory recovery in Pacific Northwest ponderosa pine forests is not fully understood, therefore, we designed this study to evaluate the potential of the seed bank as a source of desired herbaceous understory species recruitment. Seed bank samples were collected from 14 ponderosa pine stands, seven with a perennial bunchgrass dominated understory (intact) and seven with little or no understory (depauperate). Seedling emergence methods were used to estimate the germinable seed bank; seedling density and diversity comparisons were made using non-parametric Wilcoxon rank-sum tests; and seedling species composition compared using multiple response permutation procedures. Comparisons were also made between seed bank and understory vegetation species composition. No statisti...

A Comparison of Growth Efficiency of Plants on the East and West Sides of a Forest Canopy Gap

BARDEN, L. S. (Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223). A comparison of growth efficiency of plants on the east and west sides of a forest canopy gap. Bull. Torrey Bot. Club 123:240-242. 1996.-The theoretical distribution of light in a circular forest canopy gap is symmetrically equal on the east and west sides of the gap. However, small plants on the west side of the gap receive maximum light in the morning when air temperature and vapor pressure deficit are relatively low, while plants on the east side receive maximum light in the afternoon when temperature and VPD are high. To test the hypothesis that plants on the west side of a gap are able to use light more efficiently, Microstegium vimineum, a shade-adapted annual grass, was grown in pots in a forest canopy gap, both in the actual open gap and in the extended gap. In the actual gap there was no difference in growth efficiency. However, in the extended gap growth efficiency was 39% greater on the west side than on the east side under equal light (integrated photon flux density). Thus, asymmetry of microclimate on the east and west sides of a canopy gap causes an east-west asymmetry in plant growth efficiency and may induce asymmetry in species composition of understory vegetation.

Species composition of understory vegetation in coal mined land in Central Bengkulu, Indonesia

Wiryono, Siahaan AB. 2013. Species composition of understory vegetation in coal mined land in Central Bengkulu, Indonesia. Biodiversitas 14: 31-36. Coal strip mining in forest area has destroyed forest ecosystem and created barren land. Reclamation of mined land is done by revegetating the land. In addition to planted species, pioneer species usually grow naturally in mined land. The objectives of this study were to know the species composition of understory vegetation growing naturally in coal mined land planted with Gmelina arborea in Central Bengkulu, Indonesia, and to compare that composition with that of unreclaimed coal mined land and of natural forests. Data were collected by sampling understory vegetation in study site. Each plant was identified, harvested and oven-dried to find the biomass. Results showed that the reclaimed mined land had 16 understory species from 6 families, and the abandoned mined land had 10 species from 3 families, lower than that of natural forests, which were 92 and 112. The three most important species were Scleria sumatrensis Retz, Eragrostis chariis (Schult.) Hitchc and Paspalum conjugatum Berg. The species composition of understory vegetation in reclaimed mined land had high similarity with that of abandoned mined land but was totally different from that of natural forests.