scholarly journals Does insect herbivory suppress ecosystem productivity? Evidence from a temperate woodland

2021 ◽  
Author(s):  
Kristiina Visakorpi ◽  
Sofia Gripenberg ◽  
Yadvinder Malhi ◽  
Terhi Riutta
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Leaf Gas Exchange ◽  
Insect Herbivory ◽  
Ecosystem Productivity ◽  
Area Loss ◽  
Leaf Area Loss ◽  
The Relationship

AbstractOur current understanding of the relationship between insect herbivory and ecosystem productivity is limited. Previous studies have typically quantified only leaf area loss, or have been conducted during outbreak years. These set-ups often ignore the physiological changes taking place in the remaining plant tissue after insect attack, or may not represent typical, non-outbreak herbivore densities. Here, we estimate the amount of carbon lost to insect herbivory in a temperate deciduous woodland both through leaf area loss and, notably, through changes in leaf gas exchange in non-consumed leaves under non-outbreak densities of insects. We calculate how net primary productivity changes with decreasing and increasing levels of herbivory, and estimate what proportion of the carbon involved in the leaf area loss is transferred further in the food web. We estimate that the net primary productivity of an oak stand under ambient levels of herbivory is 54 - 69% lower than that of a completely intact stand. The effect of herbivory quantified only as leaf area loss (0.1 Mg C ha−1 yr−1) is considerably smaller than when the effects of herbivory on leaf physiology are included (8.5 Mg C ha−1 yr−1). We propose that the effect of herbivory on primary productivity is non-linear and mainly determined by changes in leaf gas exchange. We call for replicated studies in other systems to validate the relationship between insect herbivory and ecosystem productivity described here.

Abundance of leafminers and leaf area loss by chewing herbivores in hybrids between Quercus crispula and Quercus dentata

2004 ◽  
Vol 34 (12) ◽  
pp. 2501-2507 ◽  
Author(s):  
Takahide A Ishida ◽  
Kouhei Hattori ◽  
Masahito T Kimura
Keyword(s):  
Leaf Area ◽  
Parental Species ◽  
Quercus Crispula ◽  
Species Dominance ◽  
Area Loss ◽  
Early Instar ◽  
Sap Feeding ◽  
Leaf Area Loss ◽  
Quercus Dentata ◽  
Northern Japan

We examined responses of phytophagous insects to hybrids between Quercus crispula Blume and Quercus dentata Thunberg in a natural population in northern Japan. The abundance of leafminers and leaf area loss by chewing insects in hybrids were intermediate between those in the parental species (additive mode), close to those of either of the parental species (dominance mode), or similar to those of both parental species (no difference). Hybrids were neither more susceptible nor resistant to the insect herbivores we monitored. In Phyllonorycter (Gracillariidae) species, which are specialized to either of the parental oak species, the mortality of sap-feeding early instar larvae did not differ between hybrids and the parental species. The abundance of four leafminer taxa was correlated with environmental conditions (i.e., distance from the coastal edge of the forest or the timing of budbreak) as well as genetic factors.

scholarly journals The Variation on Tempo-Spatial Pattern of Main Pastoral Grasslands in China

2018 ◽  
Author(s):  
Wei Zhou ◽  
Lu Huang ◽  
Han Yang ◽  
Xuemin Nie
Keyword(s):  
Primary Productivity ◽  
Theoretical Basis ◽  
Net Primary Productivity ◽  
Ecological Engineering ◽  
Grassland Ecosystem ◽  
Ecosystem Productivity ◽  
Landscape Index ◽  
Ecological Patterns ◽  
Rational Management ◽  
Landscape Ecological

In order to explore the grassland ecosystem productivity and landscape ecological patterns of main pastoral grasslands in China, it provides a theoretical basis for the efficient implementation of ecological engineering and rational management of grassland resources in the region. This study analyzed the changes in grassland area, landscape index (LSI), and net primary productivity (NPP) in seven major pastoral areas in China in 1985, 1995, 2005, and 2015. Results showed that (1) the sizes of the grassland study area in 1985, 1995, 2005, and 2015 were 248.34, 243.93, 245.80, and 244.660 km2 respectively. (2) The dominance of grassland in the landscape pattern increased from 2005 to 2015 as compared with that in 1985–1995 and 1995–2005. The degrees of spatial heterogeneity were reduced. (3) The grassland NPP showed spatial and temporal differences. The average NPP of grassland increased by 21.30%, 16.47%, and 36.17% during 1985–1995, 2005–2015, and 1985–2015, respectively. From 1995 to 2005, the average NPP decreased by 5.05 gC/m2, which is equivalent to -3.61% of the average NPP in 1995. The total amount of grassland NPP in the study area was the greatest in 2015, showing increments of 36.37% and 16.61% compared with those in 1985 and 2005, respectively.

The Variation on Tempo-Spatial Pattern of Main Pastoral Grasslands in China

2018 ◽  
Author(s):  
Wei Zhou ◽  
Lu Huang ◽  
Han Yang ◽  
Xuemin Nie
Keyword(s):  
Primary Productivity ◽  
Theoretical Basis ◽  
Net Primary Productivity ◽  
Ecological Engineering ◽  
Grassland Ecosystem ◽  
Ecosystem Productivity ◽  
Landscape Index ◽  
Ecological Patterns ◽  
Rational Management ◽  
Landscape Ecological

In order to explore the grassland ecosystem productivity and landscape ecological patterns of main pastoral grasslands in China, it provides a theoretical basis for the efficient implementation of ecological engineering and rational management of grassland resources in the region. This study analyzed the changes in grassland area, landscape index (LSI), and net primary productivity (NPP) in seven major pastoral areas in China in 1985, 1995, 2005, and 2015. Results showed that (1) the sizes of the grassland study area in 1985, 1995, 2005, and 2015 were 248.34, 243.93, 245.80, and 244.660 km2 respectively. (2) The dominance of grassland in the landscape pattern increased from 2005 to 2015 as compared with that in 1985–1995 and 1995–2005. The degrees of spatial heterogeneity were reduced. (3) The grassland NPP showed spatial and temporal differences. The average NPP of grassland increased by 21.30%, 16.47%, and 36.17% during 1985–1995, 2005–2015, and 1985–2015, respectively. From 1995 to 2005, the average NPP decreased by 5.05 gC/m2, which is equivalent to -3.61% of the average NPP in 1995. The total amount of grassland NPP in the study area was the greatest in 2015, showing increments of 36.37% and 16.61% compared with those in 1985 and 2005, respectively.

Stomatal conductance and gas exchange in four species of Caribbean mangroves exposed to ambient and increased CO2

1998 ◽  
Vol 49 (4) ◽  
pp. 325 ◽  
Author(s):  
Samuel C. Snedaker ◽  
Rafael J. Araújo
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
South Florida ◽  
Avicennia Germinans ◽  
Laguncularia Racemosa ◽  
Conocarpus Erectus ◽  
Sun Leaves ◽  
Ambient Co2

Stomatal conductance and gas exchange rates in sun leaves were measured in multiple individuals of four species of Caribbean mangroves common to south Florida, USA. Under ambient CO2 levels (340–360 ppm), stomatal conductance (mol m-2 s-1), net primary productivity (g CO2 m-2 min-1), transpiration (g H2O m-2 s-1), and instantaneous transpiration efficiency, ITE, (µmol CO2/mmol H2O) were not significantly different among the four species: Rhizophora mangle (Rm), Avicennia germinans (Ag), Laguncularia racemosa (Lr), and Conocarpus erectus (Ce). Under exposure to increased CO2 (361–485 ppm) there were highly significant (P < 0.001) decreases in stomatal conductance and transpiration, and a highly significant increase in ITE in all four species. However, there was no significant change in net primary productivity in Rm, Ag and Ce, whereas there was a significant decrease (P < 0.01) in net primary productivity in Lr.

scholarly journals HUBUNGAN PRODUKTIVITAS PRIMER FITOPLANKTON DENGAN KETERSEDIAAN UNSUR HARA DAN INTENSITAS CAHAYA DI PERAIRAN TELUK KENDARI SULAWESI TENGGARA

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Nur Irawati, Enan M. Adiwilaga Dan Niken T.M. Prawtiwi
Keyword(s):  
Light Intensity ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
River Mouth ◽  
Sampling Station ◽  
Nutrient Element ◽  
Data Description ◽  
Average Value ◽  
Main Factors ◽  
The Relationship

ABSTRAKPenelitian ini merupakan kajian tentang hubungan produktivitas primer fitoplankton denganketersediaan unsur hara dan intensitas cahaya di perairan Teluk Kendari. Penelitian ini dilaksanakan diPerairan Teluk Kendari pada bulan April – Juni 2009 dengan menempatkan 3 stasiun penelitian.Tujuan penelitian adalah mengkaji hubungan antara produktivitas primer fitoplankton (NPP) denganketersediaan unsur hara dan intensitas cahaya (ICM) di perairan Teluk Kendari. Hasil penelitianmenunjukkan bahwa nilai produktivitas primer selama penelitian pada perairan Teluk Kendari yaitupada stasiun luar teluk berkisar 16,99 – 26,37 mgC/m3/4 jam, pada stasiun tengah teluk 21,09 – 31,25mgC/m3/4 jam, dan 11,13–24,61 mgC/m3/4 jam pada stasiun dalam teluk. Hubungan produktivitasprimer dengan unsur hara dan ICM memperlihatkan keeratan hubungan yang kuat pada ketiga stasiunpenelitian sedang produktivitas primer dengan unsur hara dan ICM menunjukkan pola yang hampirsama pada ketiga stasiun penelitian. Pada stasiun luar teluk, unsur hara amonia dan nitrat bersamaICM menjadi faktor yang memberikan pengaruh nyata terhadap tinggi rendahnya nilai NPP, sedangpada stasiun tengah dan dalam teluk, unsur hara nitrat dan ICM memberikan pengaruh yang nyataterhadap tinggi dan rendahnya nilai NPP di perairan Teluk Kendari.ABSTRACTThe sudy on the Phytoplankton primary productivity relationship to the availability of nutrientelement and light intensity in the waters of Kendari Bay was conducted on April-June 2009 at threesites. The purpose of this research was to examine the relationship between primary productivity ofphytoplankton with nutrient availability and light intensity in the waters of the Bay of Kendari. Basedon the data description and laboratory analysis, net primary productivity values during the surveyperiod varied from 11.13 to 31.25 mgC/m3/4 hour with ranges of average value of NPP from 20.0 to24.46 mgC/m3/4 hour. Sampling station located at the middle of the bay had the highest NPP valuefollowed by sampling station positioned at the mouth of the bay and the lowest value was found atsampling station located near the river mouth of the upper part of the bay. Relationship betweenprimary productivity and light intensity depicted a strong correlation at the three sampling stations.Relationship of primary productivity to nutrient and light intensity showed that the relationship werehigh in all three stations. Similar pattern of relationship were shown among the three stations. At thestation located out of the Kendari Bay, nutrient element N (both ammonia and nitrate) and lightintensity were the main factors that signifacantly influence the level of NPP value, while stationlocated in the middle and inside the bay, results reveal that nitrate and light intensity had significatinflunce on the level of NPP values.Key words: primary productivity of phytoplankton, nutrient elements, light intensity

Reexamining the empirical relation between plant growth and leaf photosynthesis

2006 ◽  
Vol 33 (5) ◽  
pp. 421 ◽  
Author(s):  
Eric L. Kruger ◽  
John C. Volin
Keyword(s):  
Gas Exchange ◽  
Plant Growth ◽  
Leaf Area ◽  
Leaf Gas Exchange ◽  
Empirical Relation ◽  
Leaf Photosynthesis ◽  
Unit Leaf Area ◽  
Leaf Mass ◽  
Unit Leaf ◽  
Growth Variation

Technological advances during the past several decades have greatly enhanced our ability to measure leaf photosynthesis virtually anywhere and under any condition. Associated with the resulting proliferation of gas-exchange data is a lingering uncertainty regarding the importance of such measurements when it comes to explaining intrinsic causes of plant growth variation. Accordingly, in this paper we rely on a compilation of data to address the following questions: from both statistical and mechanistic standpoints, how closely does plant growth correlate with measures of leaf photosynthesis? Moreover, in this context, does the importance of leaf photosynthesis as an explanatory variable differ among growth light environments? Across a wide array of species and environments, relative growth rate (RGR) was positively correlated with daily integrals of photosynthesis expressed per unit leaf area (Aarea), leaf mass (Amass), and plant mass (Aplant). The amount of RGR variation explained by these relationships increased from 36% for the former to 93% for the latter. Notably, there was close agreement between observed RGR and that estimated from Aplant after adjustment for theoretical costs of tissue construction. Overall, based on an analysis of growth response coefficients (GRCs), gross assimilation rate (GAR), a photosynthesis-based estimate of biomass gain per unit leaf area, explained about as much growth variation as did leaf mass ratio (LMR) and specific leaf area (SLA). Further analysis of GRCs indicated that the importance of GAR in explaining growth variation increased with increasing light intensity. Clearly, when considered in combination with other key determinants, appropriate measures of leaf gas exchange effectively capture the fundamental role of leaf photosynthesis in plant growth variation.

Mechanisms promoting recovery from defoliation in goldenrod (Solidago altissima)

1998 ◽  
Vol 76 (3) ◽  
pp. 450-459 ◽  
Author(s):  
G A Meyer
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Unit Area ◽  
Total Carbon ◽  
Carbon Gain ◽  
Solidago Altissima ◽  
Photosynthetic Rates ◽  
Area Loss ◽  
Compensatory Photosynthesis ◽  
Leaf Area Loss

Plant responses to defoliation were examined using Solidago altissima and a leaf-chewing beetle (Trirhabda sp.). Plants were exposed to five intensities of defoliation (ranging from 0 to 85% leaf area loss) and effects on carbon gain, vegetative growth, and flowering were determined. Defoliated plants partially restored their capacity for carbon gain in the following ways: (i) activity of damaged leaves remaining after defoliation was increased via delayed senescence and enhanced photosynthetic rates and (ii) regrowth leaves on damaged plants had higher specific leaf area (leaf area per leaf mass) than comparable leaves on undamaged plants, but photosynthetic rates per unit area were equivalent to controls; thus, these leaves covered more area for a given investment in biomass with no loss in activity per unit area. Delayed leaf senescence and compensatory photosynthesis are commonly observed following defoliation, but increased specific leaf area is not generally recognized as a mechanism contributing to plant regrowth. In spite of these changes, total carbon gain capacity of defoliated plants was still less than that of controls after 3 weeks of regrowth. Overall plant performance was reduced by defoliation. Defoliated stems grew at a slower rate early in the season, added fewer new leaves in the first few weeks after defoliation, and had fewer lateral stems throughout the season. Damaged plants delayed flowering and maintained height growth later into the season than undamaged plants. Damaged stems reached heights comparable with undamaged stems by the end of the season, but they were thinner and their flower production was lower. Declines in plant growth and flowering were linear functions of the percentage leaf area loss, suggesting that even low levels of insect feeding are likely to affect plant performance.Key words: Solidago altissima, Trirhabda, defoliation, compensatory photosynthesis, insect herbivory, herbivore damage, plant compensation.

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