Phylogenetic constraints to soil properties determine elevational diversity gradients of forest understory vegetation

The spatial structure of vegetation and soil properties of a patchy Scots pine (Pinussylvestris L.) forest of 1 ha was described and examined in relation to the height growth of pine seedlings in the understory. Measured ecosystem properties included the distribution and sizes of canopy trees, within-stand radiation regime, composition of understory vegetation, and topsoil and mineral soil properties. The joint distance dependent effects of large trees were described as the influence potential, derived from the ecological field theory approach. The variation in understory vegetation and soil characteristics was described as score values, derived from multivariate analyses, summarizing the variation of multiple measured variables; factor analysis was used for topsoil and mineral soil properties and canonical correspondence analysis was used for understory species composition. The spatial variation of variables was examined and mapped using geostatistical techniques. The influence potential of canopy trees, as determined by their size and spatial distribution, correlated most strongly with seedling growth, so that the height growth of seedlings was retarded in the vicinity of trees. Correlations suggest that canopy trees also affected seedlings indirectly through their dominating effect on the properties of understory vegetation and humus layer. The mineral soil nutrient content showed a weak positive correlation with seedling height growth. All the factors related to seedling growth showed substantial small-scale variation across the 1-ha study site. The analysis suggests that the variation in seedling height growth in the understory of the studied Scots pine stand is largely caused by the spatial heterogeneity of both above- and below-ground factors and by the joint effect of their complex interaction.

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Testing the Ability of Airborne LiDAR to Measure Forage Resources for Wild Ungulates in Conifer Forests

Journal of Forestry ◽

10.1093/jofore/fvz040 ◽

2019 ◽

Vol 117 (5) ◽

pp. 492-503 ◽

Cited By ~ 1

Author(s):

Iver T Hull ◽

Lisa A Shipley

Keyword(s):

Food Resource ◽

Canopy Cover ◽

Laser Pulses ◽

Understory Vegetation ◽

Airborne Lidar ◽

Forest Understory ◽

Conifer Forests ◽

Vegetation Density ◽

Wild Ungulates ◽

Vegetation Biomass

Abstract Vegetation in the forest understory is a key food resource for wild ungulates like deer (Odocoileus spp.) because the amount of nutritious forage influences animal productivity and density. Therefore, measuring the abundance of understory vegetation available to wildlife populations is often a key objective for wildlife managers. Field-based methods for measuring understory vegetation across remote landscapes are time- and resource-intensive, so we compared estimates of understory vegetation density derived from airborne light detection and ranging (LiDAR) returns with vegetation biomass sampled directly on 65 field plots across 4 years and >250,000 hectares of xeric conifer forests in northeastern Washington. We found that LiDAR-derived estimates of understory vegetation density were only able to predict field-sampled vegetation biomass when the two sampling methods occurred within 3 years of each other, and overstory canopy cover was <50 percent. Our results demonstrate limitations in the ability of LiDAR, at the intensity and frequency currently applied for multiuse purposes, to measure the quantity of forage. However, further testing with synchronous field sampling and higher-density laser pulses holds promise.

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Initial quantitative characterization of soil nutrient regimes. II. Relationships among soils, vegetation, and site index

Canadian Journal of Forest Research ◽

10.1139/x87-240 ◽

1987 ◽

Vol 17 (12) ◽

pp. 1565-1571 ◽

Cited By ~ 12

Author(s):

R. D. Kabzems ◽

K. Klinka

Keyword(s):

Soil Properties ◽

Nutrient Availability ◽

Soil Nutrient ◽

Site Index ◽

Douglas Fir ◽

Understory Vegetation ◽

Moisture Regime ◽

Soil Nutrient Availability ◽

Total N ◽

Highly Correlated

Relationships between soil properties, understory vegetation, foliar properties, and site index were examined in some Douglas-fir ecosystems on Vancouver Island. Multivariate summaries of variation in understory vegetation and foliar properties were highly correlated with the soil properties (mineralizable N, total N, and exchangeable Ca and Mg) that best characterized soil nutrient regimes of the ecosystems. The increases in soil nutrient availability were correlated with increased foliar N concentrations of the current year foliage. A consistent correlation was found between increased soil nutrient availability (particularly N, Mg, Ca) and decreased foliar Mn and Al. Site index of Douglas-fir was significantly greater on sites with greater quantities of most nutrients (particularly N, Mg, Ca) when sites with equivalent soil moisture regime were compared.

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Forest Understory Vegetation along a Productivity Gradient

The Journal of the Torrey Botanical Society ◽

10.2307/4126926 ◽

2004 ◽

Vol 131 (1) ◽

pp. 32 ◽

Cited By ~ 15

Author(s):

Greg P. Adkison ◽

Scott K. Gleeson

Keyword(s):

Understory Vegetation ◽

Forest Understory ◽

Productivity Gradient

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Forest harvesting impacts on soil properties and vegetation communities in the Northwest Territories

Canadian Journal of Forest Research ◽

10.1139/x02-014 ◽

2002 ◽

Vol 32 (4) ◽

pp. 713-724 ◽

Cited By ~ 34

Author(s):

Michael D Bock ◽

Ken CJ Van Rees

Keyword(s):

Species Composition ◽

Soil Properties ◽

Forest Harvesting ◽

Understory Vegetation ◽

Vegetation Community ◽

Clear Cut ◽

Mixedwood Forests ◽

Crown Cover ◽

Composition And Structure ◽

Harvesting Systems

Management of boreal mixedwood forests in Canada has traditionally relied almost exclusively on the clear-cut silvicultural system. In recent years, greater utilization of the hardwood component of boreal mixedwoods and increased societal concerns over maintenance of the integrity and sustainability of these ecosystems has provided impetus for forest managers to consider alternative silvicultural practices in boreal mixedwood forests. Little is currently known, however, concerning the response of soils and vegetation to forest harvesting systems in the mixedwood forests of the Liard River valley, Northwest Territories (NWT). Therefore, the objective of this study was to quantify the effects of patch clear-cut, strip clear-cut, and clear-cut harvesting systems on soil properties and understory vegetation composition and structure. Treatment sites with 3 or 4 years of recovery since harvesting and adjacent uncut forest sites were sampled using transect methodology. Soil samples were collected and understory vegetation community species composition and percent crown cover were assessed in 1-m2 quadrats. Compared with the range of conditions present in the uncut forest, increases in mineral soil bulk density (2%), exchangeable calcium (7%), LFH horizon thickness (13%), pH (0.2 units), and total organic carbon (5%) and decreases in LFH horizon total nitrogen (6%) and exchangeable potassium (22%) were observed following harvesting. Harvesting resulted in the reduction in crown cover of feathermoss species and increased abundance of shrub and herb species and minimal changes to species composition. Multivariate analysis of the data indicated that the method of harvesting did not result in significant differences in species composition and structure of the understory vegetation community. Overall, winter harvesting of these boreal mixedwood sites did not have a major impact on the majority of soil properties evaluated or on the species composition of the understory vegetation community.

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Understory vegetation relationships with soil element contents in a northern boreal forest ecosystem near a phosphate massif

10.5194/bg-2019-110 ◽

2019 ◽

Author(s):

Laura Matkala ◽

Maija Salemaa ◽

Jaana Bäck

Keyword(s):

Leaf Litter ◽

Understory Vegetation ◽

Forest Understory ◽

Nutrient Contents ◽

Humus Layer ◽

P Content ◽

Relationship Of ◽

The Relationship ◽

Total P ◽

Better Than

Abstract. We studied the relationship of forest understory vegetation with nutrient contents of soil and tree leaves near Sokli phosphate ore in northern Finland, where the soil contains naturally high variation in phosphorus (P) contents. At most study plots boreal dwarf shrubs, bryophytes and lichen formed a dense mat under a mixture of sparsely growing Pinus sylvestris, Picea abies and Betula pubescens. However, some plots were dominated by B. pubescens and had a higher variety and number of forbs and grasses in the understory. The total P content in the soil humus layer explained the abundance and species composition of the vegetation slightly better than the total nitrogen content. The spatial variation in contents of soil elements was high both between and within plots, emphasizing the heterogeneity of soil. High contents of P in the humus layer (max. 2600 mg kg−1) were measured from the birch-dominated plots. As the P contents of birch leaves and leaf litter were also rather high (2580 mg kg−1 and 1280 mg kg−1, respectively), this may imply that the leaf litter of birch forms an important source of P to the soil.

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Decreased variation of forest understory vegetation is an effect of fertilisation in young stands of Picea abies

Scandinavian Journal of Forest Research ◽

10.1080/02827581.2011.564397 ◽

2011 ◽

Vol 26 (S11) ◽

pp. 46-55 ◽

Cited By ~ 10

Author(s):

Per-Ola Hedwall ◽

Jörg Brunet ◽

Annika Nordin ◽

Johan Bergh

Keyword(s):

Picea Abies ◽

Understory Vegetation ◽

Forest Understory

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Separating overstory and understory leaf area indices for global needleleaf and deciduous broadleaf forests by fusion of MODIS and MISR data

Biogeosciences ◽

10.5194/bg-14-1093-2017 ◽

2017 ◽

Vol 14 (5) ◽

pp. 1093-1110 ◽

Cited By ~ 20

Author(s):

Yang Liu ◽

Ronggao Liu ◽

Jan Pisek ◽

Jing M. Chen

Keyword(s):

Leaf Area ◽

Water Cycle ◽

Field Measurements ◽

Absolute Error ◽

Mean Value ◽

Understory Vegetation ◽

Forest Understory ◽

Ecosystem Functions ◽

Canopy Reflectance ◽

Area Index

Abstract. Forest overstory and understory layers differ in carbon and water cycle regimes and phenology, as well as ecosystem functions. Separate retrievals of leaf area index (LAI) for these two layers would help to improve modeling forest biogeochemical cycles, evaluating forest ecosystem functions and also remote sensing of forest canopies by inversion of canopy reflectance models. In this paper, overstory and understory LAI values were estimated separately for global needleleaf and deciduous broadleaf forests by fusing MISR and MODIS observations. Monthly forest understory LAI was retrieved from the forest understory reflectivity estimated using MISR data. After correcting for the background contribution using monthly mean forest understory reflectivities, the forest overstory LAI was estimated from MODIS observations. The results demonstrate that the largest extent of forest understory vegetation is present in the boreal forest zones at northern latitudes. Significant seasonal variations occur for understory vegetation in these zones with LAI values up to 2–3 from June to August. The mean proportion of understory LAI to total LAI is greater than 30 %. Higher understory LAI values are found in needleleaf forests (with a mean value of 1.06 for evergreen needleleaf forests and 1.04 for deciduous needleleaf forests) than in deciduous broadleaf forests (0.96) due to the more clumped foliage and easier penetration of light to the forest floor in needleleaf forests. Spatially and seasonally variable forest understory reflectivity helps to account for the effects of the forest background on LAI retrieval while compared with constant forest background. The retrieved forest overstory and understory LAI values were compared with an existing dataset for larch forests in eastern Siberia (40–75° N, 45–180° E). The retrieved overstory and understory LAI is close to that of the existing dataset, with an absolute error of 0.02 (0.06), relative error of 1.3 % (14.3 %) and RMSE of 0.93 (0.29) for overstory (understory). The comparisons between our results and field measurements in eight forest sites show that the R2 values are 0.52 and 0.62, and the RMSEs are 1.36 and 0.62 for overstory and understory LAI, respectively.

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