Effect of Removal of Hesperis matronalis (Dame's Rocket) on Species Cover of Forest Understory Vegetation in NW Indiana

2009 ◽  
Vol 161 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Noel B. Pavlovic ◽  
Stacey A. Leicht-Young ◽  
Krystalynn J. Frohnapple ◽  
Ralph Grundel
2019 ◽  
Vol 117 (5) ◽  
pp. 492-503 ◽  
Author(s):  
Iver T Hull ◽  
Lisa A Shipley

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.


Plant Ecology ◽  
2017 ◽  
Vol 218 (7) ◽  
pp. 821-834 ◽  
Author(s):  
Nobuhiko Shigyo ◽  
Kiyoshi Umeki ◽  
Haruka Ohashi ◽  
Kiyokazu Kawada ◽  
Toshihide Hirao

2019 ◽  
Author(s):  
Laura Matkala ◽  
Maija Salemaa ◽  
Jaana Bäck

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.


2017 ◽  
Vol 14 (5) ◽  
pp. 1093-1110 ◽  
Author(s):  
Yang Liu ◽  
Ronggao Liu ◽  
Jan Pisek ◽  
Jing M. Chen

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.


2010 ◽  
Vol 91 (9) ◽  
pp. 1811-1820 ◽  
Author(s):  
Leena Hamberg ◽  
Minna Malmivaara-Lämsä ◽  
Susanna Lehvävirta ◽  
Robert B. O’Hara ◽  
D. Johan Kotze

Ecography ◽  
2021 ◽  
Author(s):  
Josep Padullés Cubino ◽  
Idoia Biurrun ◽  
Gianmaria Bonari ◽  
Tatiana Braslavskaya ◽  
Xavier Font ◽  
...  

2019 ◽  
Vol 30 (4) ◽  
pp. 746-755 ◽  
Author(s):  
Robert Weigel ◽  
Jennifer Gilles ◽  
Marcin Klisz ◽  
Michael Manthey ◽  
Juergen Kreyling

2004 ◽  
Vol 82 (9) ◽  
pp. 1314-1323 ◽  
Author(s):  
Han YH Chen ◽  
Sonia Légaré ◽  
Yves Bergeron

Although various conceptual models exist to explain the pattern of diversity along a productivity gradient, studies of forest understory vegetation along a natural gradient of productivity are often confounded with changes in overstory cover types. We investigated how understory vegetation composition, cover, structure, and diversity change along a productivity gradient in 60 monodominant Populus stands in northeastern British Columbia. A partial canonical correspondence analysis indicated that understory vegetation composition was significantly related to aspen site index – dominant aspen tree height at breast-height age 50 years and several climate and soil variables, but not to stand basal area, density, or aboveground biomass, values that served as an index of light availability to forest understory. Indicator species analysis showed that Cornus sericea, Galium trifidum, and Equisetum pratense were associated with the higher productivity class, while Geocaulon lividum, Vaccinium vitis-idaea, Vaccinium myrtilloides, and bryophytes like Polytrichum juniperinum and Pleurozium schreberi occurred only on poor sites. Total cover of all understory plants, woody plants, and herbaceous species did not vary, but that of bryophytes and lichens decreased from poor to intermediate sites, and diversity indices of total, woody, and herbaceous plants increased significantly with the site index. The greater diversity on more productive sites may be associated with greater spatial and resource heterogeneity.Key words: trembling aspen, forest productivity, site index, understory vegetation, species composition, diversity index.


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