You'd better walk alone: Changes in forest composition affect pollination efficiency and pre-dispersal cone damage in IberianJuniperus thuriferaforests

Plant Biology ◽  
2017 ◽  
Vol 19 (6) ◽  
pp. 934-941 ◽  
Author(s):  
E. Rodríguez-García ◽  
E. T. Mezquida ◽  
J. M. Olano
Keyword(s):  
Forest Composition ◽  
Pollination Efficiency ◽  
Cone Damage

scholarly journals Predicting Damage to Hop Cones by Tetranychus urticae (Acari: Tetranychidae)

2021 ◽  
Author(s):  
Joanna L Woods ◽  
Anne E Iskra ◽  
David H Gent
Keyword(s):  
Risk Factors ◽  
Tetranychus Urticae ◽  
Crop Damage ◽  
Equation Modeling ◽  
Data Sets ◽  
Current Management ◽  
Late Season ◽  
Model Based ◽  
Predatory Arthropods ◽  
Cone Damage

Abstract Twospotted spider mite (Tetranychus urticae Koch) is a cosmopolitan pest of numerous plants, including hop (Humulus lupulus L.). The most costly damage from the pest on hop results from infestation of cones, which are the harvested product, which can render crops unsalable if cones become discolored. We analyzed 14 yr of historical data from 312 individual experimental plots in western Oregon to identify risk factors associated with visual damage to hop cones from T. urticae. Logistic regression models were fit to estimate the probability of cone damage. The most predictive model was based on T. urticae-days during mid-July to harvest, which correctly predicted occurrence and nonoccurrence of cone damage in 91 and 93% of data sets, respectively, based on Youden’s index. A second model based on the ratio of T. urticae to predatory arthropods late in the season correctly predicted cone damage in 92% of data sets and nonoccurrence of damage in 77% of data sets. The model based on T. urticae abundance performed similarly when validated in 23 commercial hop yards, whereas the model based on the predator:prey ratio was relatively conservative and yielded false-positive predictions in 11 of the 23 yards. Antecedents of these risk factors were explored and quantified by structural equation modeling. A simple path diagram was constructed that conceptualizes T. urticae invasion of hop cones as dependent on prior density of the pest on leaves in early spring and summer, which in turn influences the development of predatory arthropods that mediate late-season density of the pest. In summary, the biological insights and models developed here provide guidance to pest managers on the likelihood of visual cone damage from T. urticae that can inform late-season management based on both abundance of the pest and its important predators. This is critically important because a formal economic threshold for T. urticae on hop does not exist and current management efforts may be mistimed to influence the pest when crop damage is most probable. More broadly, this research suggests that current management practices that target T. urticae early in the season may in fact predispose yards to later outbreaks of the pest.

scholarly journals Forest plant and macrofungal differences in the Greater and Lesser Khingan Mountains in Northeast China: A regional-historical comparison and its implications

2021 ◽  
Author(s):  
Yuanyuan Wang ◽  
Hui Wen ◽  
Kai Wang ◽  
Jingxue Sun ◽  
Jinghua Yu ◽  
...  
Keyword(s):  
Northeast China ◽  
Dominant Species ◽  
Local Economy ◽  
Forest Composition ◽  
Historical Records ◽  
Historical Comparison ◽  
Composition And Structure ◽  
Total State ◽  
The 1960S ◽  
Forest Plants

AbstractForests in Northeast China in the Greater and Lesser Khingan Mountains (GKM and LKM) account for nearly 1/3 of the total state-owned forests in the country. Regional and historical comparisons of forest plants and macrofungi will favor biological conservation, forest management and economic development. A total of 1067 sampling plots were surveyed on forest composition and structure, with a macrofungi survey at Liangshui and Huzhong Nature Reserves in the center of two regions. Regional and historical differences of these parameters were analyzed with a redundancy ordination of their complex associations. There were 61–76 families, 189–196 genera, and 369–384 species, which was only 1/3 of the historical records. The same dominant species were larch and birch with Korean pine (a climax species) less as expected from past surveys in the LKM. Shrub and herb species were different in the two regions, as expected from historical records. There was 10–50% lower species diversity (except for herb evenness), but 1.8- to 4-time higher macrofungi diversity in the GKM. Compared with the LKM, both tree heights and macrofungi density were higher. Nevertheless, current heights averaging 10 m are half of historical records (> 20 m in the 1960s). Edible macrofungi were the highest proportion in both regions, about twice that of other fungal groups, having important roles in the local economy. A major factor explaining plant diversity variations in both regions was herb cover, followed by shrubs in the GKM and herb-dominant species in the LKM. Factors responsible for macrofungi variations were tree density and shrub height. Vaccinium vitis-idaea and Larix gmelinii in the GKM but tree size and diversity were important factors in the LKM. Our findings highlighted large spatial and historical differences between the GKM and LKM in plant-macrofungal composition, forest structure, and their complex associations, which will favor precise conservation and management of forest resources in two region in the future.

scholarly journals Over half of western United States' most abundant tree species in decline

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hunter Stanke ◽  
Andrew O. Finley ◽  
Grant M. Domke ◽  
Aaron S. Weed ◽  
David W. MacFarlane
Keyword(s):  
United States ◽  
Tree Species ◽  
Tree Mortality ◽  
Temperate Forests ◽  
Size Structure ◽  
Forest Disturbance ◽  
Population Decline ◽  
Western United States ◽  
Scale Transformation ◽  
Forest Composition

AbstractChanging forest disturbance regimes and climate are driving accelerated tree mortality across temperate forests. However, it remains unknown if elevated mortality has induced decline of tree populations and the ecological, economic, and social benefits they provide. Here, we develop a standardized forest demographic index and use it to quantify trends in tree population dynamics over the last two decades in the western United States. The rate and pattern of change we observe across species and tree size-distributions is alarming and often undesirable. We observe significant population decline in a majority of species examined, show decline was particularly severe, albeit size-dependent, among subalpine tree species, and provide evidence of widespread shifts in the size-structure of montane forests. Our findings offer a stark warning of changing forest composition and structure across the western US, and suggest that sustained anthropogenic and natural stress will likely result in broad-scale transformation of temperate forests globally.

Comparison of the pollination efficiency of Apis cerana with wild bees in oil-seed camellia fields

2021 ◽  
Author(s):  
Hong-Ying Li ◽  
An-Cai Luo ◽  
You-Jin Hao ◽  
Fei-Yue Dou ◽  
Ruo-Mei Kou ◽  
...  
Keyword(s):  
Apis Cerana ◽  
Pollination Efficiency ◽  
Wild Bees ◽  
Oil Seed

Landscape Eragmentation and Forest Composition Effects on Grouse Breeding Success in Boreal Forests

Ecology ◽  
2000 ◽  
Vol 81 (7) ◽  
pp. 1985 ◽  
Author(s):  
Sami Kurki ◽  
Ari Nikula ◽  
Pekka Helle ◽  
Harto Linden
Keyword(s):  
Breeding Success ◽  
Boreal Forests ◽  
Forest Composition ◽  
Composition Effects

The composition of Amazonian forests: patterns at local and regional scales

1998 ◽  
Vol 14 (5) ◽  
pp. 645-664 ◽  
Author(s):  
John Terborgh ◽  
Ellen Andresen
Keyword(s):  
Detrended Correspondence Analysis ◽  
Forest Composition ◽  
Level Data ◽  
Tree Communities ◽  
Floristic Patterns ◽  
Edaphic Properties ◽  
Number Of Stems ◽  
Amazonian Forests ◽  
Amazonian Region ◽  
The Guianas

An analysis was conducted of floristic patterns contained in 48 1-ha tree plots distributed at 29 sites in seven neotropical countries, with a primary emphasis on the Amazonian region. Analyses were made with family level data, using detrended correspondence analysis and multidimensional scaling to generate two-dimensional ordinations. Dissimilarity values for all pairs of plots were then used to compare forest composition at both local (flooded vs unflooded forests) and regional scales (e.g., western vs central vs eastern Amazonia). The predominate family of trees in a large majority of Amazonian and Guianan forests (by number of stems) is either Palmae or Leguminosae (sensu latu), followed by Moraceae and Euphorbiaceae. The forests of western Amazonia are particularly rich in palms, Moraceae, and Myristicaceae, whereas those of eastern Amazonia and the Guianas are rich in Lecythidaceae and Chrysobalanaceae. Dissimilarity between sites increases with distance for both flooded and unflooded forests. The tree communities of flooded and unflooded forests within a region tended to resemble one another more closely than forests of either type resembled the homologous forests of the adjoining regions. Within Amazonia the edaphic properties of each region and its geological history are tightly interrelated. It is therefore difficult to distinguish between evolutionary and ecological interpretations of the results.

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