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

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

Plant Ecology ◽

10.1007/s11258-017-0732-z ◽

2017 ◽

Vol 218 (7) ◽

pp. 821-834 ◽

Cited By ~ 7

Author(s):

Nobuhiko Shigyo ◽

Kiyoshi Umeki ◽

Haruka Ohashi ◽

Kiyokazu Kawada ◽

Toshihide Hirao

Keyword(s):

Soil Properties ◽

Understory Vegetation ◽

Forest Understory ◽

Diversity Gradients ◽

Phylogenetic Constraints

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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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Nitrogen supply and other controls of carbon uptake of understory vegetation in a boreal Picea abies forest

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2019.107620 ◽

2019 ◽

Vol 276-277 ◽

pp. 107620 ◽

Cited By ~ 3

Author(s):

Sari Palmroth ◽

Lisbet H. Bach ◽

Marie Lindh ◽

Pasi Kolari ◽

Annika Nordin ◽

...

Keyword(s):

Picea Abies ◽

Nitrogen Supply ◽

Understory Vegetation ◽

Carbon Uptake

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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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