The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA

Orwig, David A.; Boucher, Peter; Paynter, Ian; Saenz, E. J.; Ли, Жан; Schaaf, Crystal B.

doi:10.1098/rsfs.2017.0044

Cited by 16 publications

(14 citation statements)

References 49 publications

(63 reference statements)

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“…4b), and now the hemlock woolly adelgid (HWA) is progressively eliminating eastern hemlock. The ecosystem consequences of hemlock loss via HWA has been a research focus at the Harvard Forest since the 1990s (Orwig and Foster 1998, Orwig et al 2008, 2012) and HWA is now causing decline and mortality at the Harvard Forest (Kim et al 2017, Orwig et al 2018).…”

Section: Discussionmentioning

confidence: 99%

Carbon budget of the Harvard Forest Long‐Term Ecological Research site: pattern, process, and response to global change

Finzi

Giasson

Plotkin

et al. 2020

Ecological Monographs

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How, where, and why carbon (C) moves into and out of an ecosystem through time are long-standing questions in biogeochemistry. Here, we bring together hundreds of thousands of C-cycle observations at the Harvard Forest in central Massachusetts, USA, a mid-latitude landscape dominated by 80-120-yr-old closed-canopy forests. These data answered four questions: (1) where and how much C is presently stored in dominant forest types; (2) what are current rates of C accrual and loss; (3) what biotic and abiotic factors contribute to variability in these rates; and (4) how has climate change affected the forest's C cycle? Harvard Forest is an active C sink resulting from forest regrowth following land abandonment. Soil and tree biomass comprise nearly equal portions of existing C stocks. Net primary production (NPP) averaged 680-750 g CÁm À2 Áyr À1 ; belowground NPP contributed 38-47% of the total, but with large uncertainty. Mineral soil C measured in the same inventory plots in 1992 and 2013 was too heterogeneous to detect change in soil-C pools; however, radiocarbon data suggest a small but persistent sink of 10-30 g CÁm À2 Áyr À1. Net ecosystem production (NEP) in hardwood stands averaged~300 g CÁm À2 Áyr À1. NEP in hemlock-dominated forests averaged 450 g CÁm À2 Áyr À1 until infestation by the hemlock woolly adelgid turned these stands into a net C source. Since 2000, NPP has increased by 26%. For the period 1992-2015, NEP increased 93%. The increase in mean annual temperature and growing season length alone accounted for~30% of the increase in productivity. Interannual variations in GPP and NEP were also correlated with increases in red oak biomass, forest leaf area, and canopy-scale lightuse efficiency. Compared to long-term global change experiments at the Harvard Forest, the C sink in regrowing biomass equaled or exceeded C cycle modifications imposed by soil warming, N saturation, and hemlock removal. Results of this synthesis and comparison to simulation models suggest that forests across the region are likely to accrue C for decades to come but may be disrupted if the frequency or severity of biotic and abiotic disturbances increases.

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Section: Discussionmentioning

confidence: 99%

Carbon budget of the Harvard Forest Long‐Term Ecological Research site: pattern, process, and response to global change

Finzi

Giasson

Plotkin

et al. 2020

Ecological Monographs

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“…There is little terrain variation in the MegaPlot, and elevation ranges from 340.2 to 367.8 meters above sea level. Soil are primarily moderately-to well-drained loam formed from glacial till [36].…”

Section: Study Site Descriptionmentioning

confidence: 99%

Tree Species Traits Determine the Success of LiDAR-Based Crown Mapping in a Mixed Temperate Forest

et al. 2020

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The ability to automatically delineate individual tree crowns using remote sensing data opens the possibility to collect detailed tree information over large geographic regions. While individual tree crown delineation (ITCD) methods have proven successful in conifer-dominated forests using Light Detection and Ranging (LiDAR) data, it remains unclear how well these methods can be applied in deciduous broadleaf-dominated forests. We applied five automated LiDAR-based ITCD methods across fifteen plots ranging from conifer- to broadleaf-dominated forest stands at Harvard Forest in Petersham, MA, USA, and assessed accuracy against manual delineation of crowns from unmanned aerial vehicle (UAV) imagery. We then identified tree- and plot-level factors influencing the success of automated delineation techniques. There was relatively little difference in accuracy between automated crown delineation methods (51–59% aggregated plot accuracy) and, despite parameter tuning, none of the methods produced high accuracy across all plots (27—90% range in plot-level accuracy). The accuracy of all methods was significantly higher with increased plot conifer fraction, and individual conifer trees were identified with higher accuracy (mean 64%) than broadleaf trees (42%) across methods. Further, while tree-level factors (e.g., diameter at breast height, height and crown area) strongly influenced the success of crown delineations, the influence of plot-level factors varied. The most important plot-level factor was species evenness, a metric of relative species abundance that is related to both conifer fraction and the degree to which trees can fill canopy space. As species evenness decreased (e.g., high conifer fraction and less efficient filling of canopy space), the probability of successful delineation increased. Overall, our work suggests that the tested LiDAR-based ITCD methods perform equally well in a mixed temperate forest, but that delineation success is driven by forest characteristics like functional group, tree size, diversity, and crown architecture. While LiDAR-based ITCD methods are well suited for stands with distinct canopy structure, we suggest that future work explore the integration of phenology and spectral characteristics with existing LiDAR as an approach to improve crown delineation in broadleaf-dominated stands.

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“…The increasing importance of T. canadensis during the last century across the plot negatively affected the distribution of Q. rubra. Its location and five-year schedule of plot sampling highlight the plot as valuable long-term infrastructure that will complement Harvard Forest, LTER, NEON, and ForestGEO research efforts (Orwig et al 2018). Because all woody stems ≥ 1 cm DBH are mapped and measured, the data have been used in a variety of complementary ways including to examine species codispersion patterns and spatial patterns of species co-occurrence (Buckley et al 2016, help inform a simulation model of forest dynamics (SORTIE (Case et al 2017)), assist with investigating crown allometry (Sullivan et al 2017) and mapping (Hastings et al 2020), and aid in identifying statistical fingerprints of foundation species (Ellison et al 2019).…”

Section: Discussionmentioning

confidence: 99%

Land-use history impacts spatial patterns and composition of woody plant species across a 35-hectare temperate forest plot

Orwig

Aylward

Buckley

et al. 2021

Preprint

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Land-use history is the template upon which contemporary plant and tree populations establish and interact with one another and exerts a legacy on the structure and dynamics of species assemblages and ecosystems. We use the first census (2010-2014) of a 35-ha forest-dynamics plot at the Harvard Forest in central Massachusetts to explore such legacies. The plot includes 108,632 live stems ≥ 1 cm in diameter (2215 individuals/ha) and 7,595 dead stems ≥ 5 cm in diameter. Fifty-one woody plant species were recorded in the plot, but two tree species - Tsuga canadensis (eastern hemlock) and Acer rubrum (red maple) - and one shrub - Ilex verticillata (winterberry) -comprised 56% of all stems. Live tree basal area averaged 42.25 m2/ha, of which 84% was represented by T. canadensis (14.0 m2/ha), Quercus rubra (northern red oak; 9.6 m2/ha), A. rubrum (7.2 m2/ha) and Pinus strobus (eastern white pine; 4.4 m2/ha). These same four species also comprised 78% of the live aboveground biomass, which averaged 245.2 Mg/ha, and were significantly clumped at distances up to 50 m within the plot. Spatial distributions of A. rubrum and Q. rubra showed negative intraspecific correlations in diameters up to at least a 150-m spatial lag, likely indicative of competition for light in dense forest patches. Bivariate marked point-pattern analysis showed that T. canadensis and Q. rubra diameters were negatively associated with one another, indicating resource competition for light. Distribution and abundance of the common overstory species are predicted best by soil type, tree neighborhood effects, and two aspects of land-use history: when fields were abandoned in the late 19th century and the succeeding forest types recorded in 1908. In contrast, a history of intensive logging prior to 1950 and a damaging hurricane in 1938 appear to have had little effect on the distribution and abundance of present-day tree species.

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The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA

Cited by 16 publications

References 49 publications

Carbon budget of the Harvard Forest Long‐Term Ecological Research site: pattern, process, and response to global change

Carbon budget of the Harvard Forest Long‐Term Ecological Research site: pattern, process, and response to global change

Tree Species Traits Determine the Success of LiDAR-Based Crown Mapping in a Mixed Temperate Forest

Land-use history impacts spatial patterns and composition of woody plant species across a 35-hectare temperate forest plot

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