Untangling positive and negative biotic interactions: views from above and below ground in a forest ecosystem.

نویسندگان

  • Rebecca A Montgomery
  • Peter B Reich
  • Brian J Palik
چکیده

In ecological communities, the outcome of plant-plant interactions represents the net effect of positive and negative interactions occurring above and below ground. Untangling these complex relationships can provide a better understanding of mechanisms that underlie plant-plant interactions and enhance our ability to predict population, community, and ecosystem effects of biotic interactions. In forested ecosystems, tree seedlings interact with established vegetation, but the mechanisms and outcomes of these interactions are not well understood. To explore such mechanisms, we manipulated above- and belowground interactions among tree seedlings, shrubs, and trees and monitored seedling survival and growth of six species (Pinus banksiana, Betula papyrifera, P. resinosa, Quercus rubra, P. strobus, and Acer rubrum) in mature pine-dominated forest in northern Minnesota, USA. The forest had a moderately open canopy and sandy soils. Understory manipulations were implemented in the forest interior and in large gaps and included removal of shrubs (no interactions), tieback of shrubs (belowground), removal of shrubs with addition of shade (aboveground), and unmanipulated shrubs (both below- and aboveground). We found that shrubs either suppressed or facilitated seedling survival and growth depending on the seedling species, source of interaction (e.g., above- or belowground), and ecological context (e.g., gap or forest interior). In general, shrubs strongly influenced survival and growth in gaps, with more modest effects in the forest interior. In gaps, the presence of shrub roots markedly decreased seedling growth and survival, supporting the idea that belowground competition may be more important in dry, nutrient-poor sites. Shrub shade effects were neutral for three species and facilitative for the other three. Facilitation was more likely for shade-tolerant species. In the forest interior, shrub shade negatively affected seedling survival for the most shade-intolerant species. For several species the net effect of shrubs masked the existence of both positive and negative interactions above and below ground. Our results highlight the complexity of plant-plant interactions, demonstrate that outcomes of these interactions vary with the nature of resource limitation and the ecophysiology of the species involved, and suggest that ecological theory that rests on particular notions of plant-plant interactions (e.g., competition) should consider simultaneous positive and negative interactions occurring above and below ground.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

اثر آشفتگی انسانی بر تنوع، زیست‌توده و نگهداشت نیتروژن و فسفردر پوشش علفی جنگل‌های بلوط دارمازو (مطالعه موردی: جنگل‌های شینه قلایی استان لرستان)

This study investigates the role of man-made disturbance on on nitrogen and phosphorus nutrient storage by herbaceous species in Gall Oak stands of Lorestan province. In order to do this study, two sites with the same physiographic and ecological conditions and different land uses were selected. Multiscale sampling plots were used randomly in each site to collect data on forest floor vegetation...

متن کامل

Ecological assessment of Mel e Gonzeh mangrove forest by AZTI's Marine Biotic Index

AMBI is an ecological marine ecosystem indicator, which provides a more intelligent assessment of ecosystems of sensitivity and resilience, and ecological role, compared to famous diversity and dominance. This study assesses ecosystem health status from the AMBI's perspective by examining the distribution and biodiversity of macrobenthoses from mangrove of Mel-e-Gonzeh in the Bushehr province. ...

متن کامل

Assessment of Effect of Road or Road Construction on Soil Physical and Chemical Properties in Northern Forests of Iran

Forests are an important economic source for human and have key role in nutrient cycle, hydrology and ecosystem performance, any interference in this vital ecosystem causes to damage to forests. Mechanical logging and road construction in forest areas have led to much soil compaction. Soil physical and chemical properties were studied in parts of road and non-road in the Darabkola forest of Ira...

متن کامل

Assessment of Effect of Road or Road Construction on Soil Physical and Chemical Properties in Northern Forests of Iran

Forests are an important economic source for human and have key role in nutrient cycle, hydrology and ecosystem performance, any interference in this vital ecosystem causes to damage to forests. Mechanical logging and road construction in forest areas have led to much soil compaction. Soil physical and chemical properties were studied in parts of road and non-road in the Darabkola forest of Ira...

متن کامل

How planting density and grazing intensity affect the above- and below-ground carbon pools in a dryland ecosystem?

Climate change is known as one of the most important environmental challenges. Sequestration of carbon in terrestrial ecosystems is a low-cost option that may be available in the near-term to mitigate increasing atmospheric CO2 concentrations, while providing additional benefits. In this study, we estimated the effects of planting density and grazing intensity on the potential of Atriplex canes...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Ecology

دوره 91 12  شماره 

صفحات  -

تاریخ انتشار 2010