THE WORLD CONFERENCE ON ECOLOGICAL RESTORATION

2005 The World Conference on Ecological Restoration 35
ture of 100-year old regenerating redwood stands managed under variable retention. Increment core data
were used to reconstruct recent diameter growth rates, tree and stand volume growth. Tree height, live
crown length, and branch-free trunk length data were used to describe vertical stand structure, and were
depicted graphically, complemented by color slides of the regenerating stands. Leaf area index and stand
density index were calculated and compared with data from old growth and regenerating stands. The
growth and vigor of the new cohort initiated by the restorative harvest treatment was assessed in small
subplots. The future growth of these trees, and other understory cohorts initiated by future harvest treatments
was discussed with reference to estimates of future canopy tree growth, crown expansion, and
growing space occupancy within the restored structure. Data collected within adjacent undisturbed redwood
stands were used to derive indicative variable retention harvest yields. The average diameter, height
and cubic volume of cut trees will inform managers interested in producing forest floor log debris or deriving
returns from restorative variable retention harvest treatments. Once key structural elements and features
of old-growth redwood stands have been defined, the data and results presented herein could guide
future restoration efforts aimed at meeting defined structural goals for old-growth restoration.
Keywords: Old-growth, redwood, Sequoia sempervirens, restoration, variable retention.
Bio-geo-chemical Cycles and their practical implications in Management of
Degraded Sites by Restoration Forestry
Bhojvaid P.P.
Conservator of Forests, South Circle, Gurgaon, Haryana, India
One of the main objectives of ‘Restoration Forestry’ is to suggest the management options for improving
degraded soil fertility through biological processes of trees. This aspect was formulated on the premise
that the sustainable productivity of a natural ecosystem is derived to a great extent from the bio-geochemical
processes of litter and soil. These processes include biomass and nutrient accumulation by carbon
assimilation, nutrient recycling by litter fall, root turnover and their subsequent decomposition and
decay resulting in humus synthesis. The soil fertility build up and its sustainability is dependent not
only on the maintenance of these activities at certain critical levels but even more importantly on their
functioning as an integrated system with regulatory mechanisms operating in a synchronized manner.
Essentially it means making the acyclic processes more cyclic thereby leading to the improvement of
structure and function of an ecosystem. Little, however, is known about the mechanism of these effects
especially with respect to restoration of degraded sites by tree planting. The discussion in this paper is
focused on these aspects of restoration forestry and their importance in field management based on biogeo-chemical
cycles of plantations raised for restoration of various categories of degraded sites such as
saline, sodic, sand dunes, waterlogged and mined spoils. It is envisaged that a judicious decision on
management of a restored area would depend on such rotations that maintain and sustain the cyclic nature
of ecosystems without jeopardizing the production from such areas.
Keywords: Ecosystem degradation- Ecological rotation- Restoration forestry-Sustainability.
Biomass and nutrient accumulation in restoration plantations of an age
sequence of Prosopis juliflora (Swartz) DC grown on degraded sodic soils in
Haryana, India
Bhojvaid P.P.
Conservator of Forests, South Circle, Gurgaon, Haryana. India
The objective of this study is to address the issue of sustainbilty of management options for Prosopis
juliflora plantations raised on sodic soils in Haryana, India set up primarily for the purpose of soil reclamation.
Sustainability, in the context of this study, is defined as the maintenance and/or enhancement
of organic matter and nutrient build up in the soils, which is driven by carbon assimilation and photosynthesis
in the living biomass and the return of organic matter to soil via litterfall and root turnover.
The approach taken was to monitor these indicators of sustainabilty along a gradient of increasing tree
biomass, detritus biomass and under-storey development and corresponding changes in soil organic
matter and nutrient build up in a 0-, 5-, 7- and 30 year old chronosequence. The intention was to examine
the sustainability of management recommendations in relation to temporal patterns of biomass and
nutrient accumulation in an age sequence of Prosopis juliflora. Specific objectives were to: (1) examine
nutrient budgets, nutrient cycling and growth partitioning in the age sequence, (2) to study dynamics of
nutrient storage in soil and vegetation biomass over time, and (3) to examine the changes in understorey
community structure in the Prosopis chronosequence.
Keywords: Sodic soils, Sustainability, Restoration, Chronosequence, Nutrient Budgets.